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Home My WebLink AboutSupplemental Application Materials 06.19.2023 HYDROLOGY STUDY Eagle Springs Solar Project Garfield County, Colorado FEBRUARY 28, 2023 PREPARED FOR: PREPARED BY: Hydrology Study Eagle Springs Solar Project Garfield County, Colorado Prepared For: The AES Corporation 2180 South 1300 East Suite 600 Salt Lake City, Utah 84106 Prepared By: Westwood 12701 Whitewater Drive, Suite 300 Minnetonka, MN 55343 (952) 937-5150 Project Number: R0042347.00 Date: January 16, 2023 03/01/2023 Hydrology Study | Eagle Springs Solar Project February 28, 2023 i | Confidential and Proprietary. TBPLS Firm #10074302 Table of Contents Executive Summary ................................................................................................ 1 1.0 Data Sources ................................................................................................. 2 2.0 Coordinate System ........................................................................................ 2 3.0 Existing Conditions....................................................................................... 3 3.1 Project Location ........................................................................................................................ 3 3.2 Watershed Hydrology .............................................................................................................. 3 3.3 Onsite Conditions ..................................................................................................................... 3 3.4 FEMA Flood Zones ................................................................................................................... 4 4.0 Proposed Conditions .................................................................................... 4 4.1 Proposed Conditions ................................................................................................................. 4 4.2 Post-Construction Stormwater Management ........................................................................... 4 5.0 FLO-2D Modeling ......................................................................................... 4 5.1 FLO-2D Modeling Overview ..................................................................................................... 4 5.2 Elevation Data ........................................................................................................................... 5 5.3 Watershed Soils and Land Cover .............................................................................................. 5 5.4 Precipitation.............................................................................................................................. 5 6.0 Flood Analysis Results ................................................................................... 5 6.1 Existing Conditions Flood Analysis .......................................................................................... 5 6.2 Scour ......................................................................................................................................... 8 7.0 Recommendations ........................................................................................ 8 8.0 Next Steps ..................................................................................................... 9 9.0 Included Output Files .................................................................................. 10 10.0 References Cited ...................................................................................... 11 Hydrology Study | Eagle Springs Solar Project February 28, 2023 ii | Confidential and Proprietary. TBPLS Firm #10074302 Tables Table 1 – Data Sources .................................................................................................................................. 2 Table 2 – Coordinate System Used ............................................................................................................... 2 Table 3 –100-Year Flood Depths Onsite ....................................................................................................... 6 Table 4 –10-Year Flood Depths Onsite ......................................................................................................... 7 Table 5 –500-Year Flood Depths Onsite ....................................................................................................... 8 Exhibits Exhibit 1: Location Map Exhibit 2: Base Hydrologic Map Exhibit 3: Soils Map Exhibit 4: Landcover Map Exhibit 5: Curve Number and Topographic Source Map Exhibit 6: 100-Year Max Flood Depth Map Exhibit 6A: 100-Year Max Flood Depth Project Area Map Exhibit 7: 100-Year Peak Velocity Map Exhibit 7A: 100-Year Peak Velocity Project Area Map Exhibit 8: 100-Year Scour Map Exhibit 9: 10-Year Max Flood Depth Map Exhibit 9A: 10-Year Max Flood Depth Project Area Map Exhibit 10: 10-Year Peak Velocity Map Exhibit 10A: 10-Year Peak Velocity Project Area Map Exhibit 11: 10-Year Scour Map Exhibit 12: 500-Year Max Flood Depth Map Exhibit 12A: 500-Year Max Flood Depth Project Area Map Exhibit 13: 500-Year Peak Velocity Map Exhibit 13A: 500-Year Peak Velocity Project Area Map Exhibit 14: 500-Year Scour Map Appendices Appendix A: NOAA Atlas 14 Precipitation Data Appendix B: Curve Number Table Hydrology Study | Eagle Springs Solar Project February 28, 2023 1 | Confidential and Proprietary. TBPLS Firm #10074302 Executive Summary The purpose of this study is to analyze and review the existing hydrology of the Eagle Springs Solar Project (Project or Site) and any impacts that the hydrology may play in the design of the proposed solar array. This report was prepared to be used by the Project Team in the design and layout of the Project and not intended for submittal to reviewing agencies for stormwater permitting. The Project Site is proposed on approximately 96 acres and is located within Garfield County, Colorado, approximately 4 miles southeast of Rifle, Colorado. The Site is located on relatively flat land that generally slopes to the northeast. The modeled watershed area encompasses approximately 94 square miles and generally slopes north. The analysis shows low water depths and velocities (Exhibits 6 through 7A) across the majority of the Site. Higher flood depths exist within flow paths and their surrounding areas located within and adjacent to the Site. There are also scattered low-lying areas with localized ponding. Minimal velocities and scour are expected on site due to the flat terrain. Based on experience with similar projects, the majority of the Site is suitable for the planned development by avoiding or designing to areas of high flood depths. Hydrology Study | Eagle Springs Solar Project February 28, 2023 2 | Confidential and Proprietary. TBPLS Firm #10074302 1.0 Data Sources Table 1 – Data Sources Task Format Source Use Elevation 1m Lidar USGS TNM FLO-2D Model Elevations Crop Data Shapefile USDA 2021 Cropland Data Layer Landcover Soils Shapefile USGS SSURGO Dataset Curve Numbers Precipitation PDF File NOAA Atlas 14 Design Storms HUC-12 Drainage Boundary Shapefile USGS Define Model Extents Site Boundary KMZ The AES Corporation Define Model Extents 2014 Aerial Photography ArcGIS Map Service USDA FSA Reference FEMA Flood Zones PDF; Shapefile FEMA Reference Culvert Locating and Sizing Aerial Imagery Google Earth Culvert Modeling 2.0 Coordinate System Table 2 – Coordinate System Used Projection State Plane Coordinate System Zone Colorado Central (FIPS 502) Datum NAD83 Planar Units Feet (U.S. Survey) Hydrology Study | Eagle Springs Solar Project February 28, 2023 3 | Confidential and Proprietary. TBPLS Firm #10074302 3.0 Existing Conditions 3.1 Project Location The Project Site covers approximately 96 acres and is located within Garfield County, Colorado (Exhibit 1). The Project Site is located approximately 150 miles west of Denver, Colorado, and is located near Rifle, Colorado. Rifle is located 4 miles northwest of the Project Area (Exhibit 1). 3.2 Watershed Hydrology The modeled watershed area encompasses approximately 94 square miles that generally slopes to the north. Several creeks flow from the south before exiting the modeled watershed and converging with the Colorado River at the northern side of the modeled watershed. The Colorado River is not included in the modeled watershed because the Project Area is approximately 150 feet above the river elevation and over 3,000 feet away. Three primary creeks convey flows into the Colorado River and are included in the model—Dry Creek, Mamm Creek, and Dry Hollow Creek. Mamm Creek is the largest and primary flow path in the modeled watershed and flows adjacent to the land the Project Area sits on. Several manmade ditches carry flows throughout the project area including the Multa Trina Ditch, Highline Ditch, and Rising Sun Ditch. During large storm events, these ditches can see increased flow rates. 3.3 Onsite Conditions The Project is located on a localized high area that sits over 100 feet above Mamm Creek which flows to the west of the Project Area. Several depressed areas and impounding structures are located on or adjacent to the Project Area and may retain water during large storm events. On the northwest portion of the Site, water may collect behind an approximately 8.5 high berm. On the western portion of the southern section of the Site, a berm structure located just outside of the Project Area may withhold water behind it in certain areas. Several ditches are located across the Site and can convey flows, especially in large storm events. In general, the Site is relatively moderately sloped with grades of less than 4% though there are locations where the slopes reach roughly 6%. US Fish and Wildlife Service National Wetlands Inventory (NWI Wetlands) provides information on the distribution of US wetlands and are shown in Exhibit 2. The NWI Wetlands dataset is not all-inclusive and other wetlands not shown may exist. The landcover on the Project area is primarily agricultural row crop, fallow, and shrubland (Exhibit 4) and has soils that are primarily belonging to Hydrologic Soil Group (HSG) C (Exhibit 3). Typically, C soils are Clay Loams. Soils belonging to Hydrologic Soil Group C exhibit low infiltration rates; therefore, standing water will be slow to infiltrate during and after storm events when compared to soils belonging to Hydrologic Soil Groups A or B. Hydrology Study | Eagle Springs Solar Project February 28, 2023 4 | Confidential and Proprietary. TBPLS Firm #10074302 The main potential hydrologic issues on Site are flooding and erosive velocities. 3.4 FEMA Flood Zones FEMA has not completed a study to determine flood hazards for the project area; therefore, the project area contains no mapped FEMA flood zones (Exhibit 2). However, this does not reduce any hydrologic risks the site may have. No preliminary or pending FEMA changes are proposed within the project area. 4.0 Proposed Conditions 4.1 Proposed Conditions The majority of the proposed solar facility will consist of above ground mounted solar modules. A climate-specific grass seed mix should be planted below the modules and would make up a majority of the land cover. A small amount of impervious surface will be added from the gravel access roads and electrical equipment pads. The Project should be designed to minimize grading and maintain existing drainage patterns. A flood analysis of pre-development and post development depths may need to be completed once civil design is finalized for permitting purposes. 4.2 Post-Construction Stormwater Management A desktop review of Garfield County Stormwater Management and Drainage Requirements identified the Garfield County Land Use and Development Code. This manual specifies guidelines for avoiding direct discharge to streams, minimizing directly-connected impervious areas, and detaining and treating runoff. A stormwater management report will need to be prepared to ensure all requirements are met. The typical solar project’s low-impact development technique of converting the land cover from a row crop field to a meadow grass will provide post-construction stormwater management to meet most agency requirements. The proposed meadow grass will act as a vegetated filter providing both runoff treatment and reduction when compared to existing conditions. As the Project design advances, the post-construction stormwater management should be reviewed in further detail with the County Engineer. 5.0 FLO-2D Modeling 5.1 FLO-2D Modeling Overview FLO-2D is a physical process model that routes rainfall runoff and flood hydrographs overflow surfaces or in channels using the dynamic wave approximation to the momentum equation. FLO-2D offers advantages over 1-D Hydrology Study | Eagle Springs Solar Project February 28, 2023 5 | Confidential and Proprietary. TBPLS Firm #10074302 models and unit hydrograph methods by allowing for breakout flows and visualization of flows across a potential site. The primary inputs are a DTM (elevation data), curve numbers, and precipitation. Major culverts impacting the site were modeled based on aerial imagery provided by Google Earth (Exhibits 6- 7). A FLO-2D model with 50-foot grid cells was utilized to model the watershed within and directly impacting the Project Site. 5.2 Elevation Data The elevation data input into the FLO-2D model was 1m Lidar data from USGS TNM (Exhibit 5). This data was exported as a single digital terrain model (DTM), which is read directly into FLO-2D. 5.3 Watershed Soils and Land Cover USDA-NRCS SSURGO soil data provides soil types within the Project boundary and full coverage of the contributing watershed. Soils are primarily classified as Hydrologic Soil Group (HSG) C within the Project boundary (Exhibit 3). Land cover was obtained from the USDA 2021 Cropland Data Layer. Exhibit 4 displays the land cover classes for the entire watershed. Curve numbers were applied to each grid cell in the FLO-2D model based on intersecting the grid with the curve numbers (Exhibit 5). 5.4 Precipitation Precipitation data was downloaded from NOAA Atlas 14 (Appendix A) and used for the FLO-2D analysis for the 500-Year, 100-Year, and 10-Year, 24-Hour storm events. A 500-Year, 100-Year, and 10-Year rainfall depth of 3.22 inches, 2.54 inches, and 1.69 inches, respectively, were averaged across the modeled watershed and used as the modeled rainfall for this location. This allows for the best initial analysis in order to determine the worst areas of flooding and erosion during storm events of varying intensities. Rainfall inputs were distributed based on a site- specific nested Atlas 14 distribution pattern. 6.0 Flood Analysis Results 6.1 Existing Conditions Flood Analysis The analysis shows low water depths and velocities (Exhibits 6 through 7A) across the majority of the Site. During a 100-year storm, the flood depths across the majority of the Project Area are less than 0.5 feet with velocities less than 1 foot/second. Certain locations may see increased ponding, such as behind the berm on the northwestern section of the Project Area, where the depths can reach as high as 3 feet. A small portion of the southern half of the Project Area may see flooding along a subtle channelized area, upstream of the berm that extents along the Hydrology Study | Eagle Springs Solar Project February 28, 2023 6 | Confidential and Proprietary. TBPLS Firm #10074302 outside of the southwestern side of the Project Area. See Table 3 below for a breakdown of flood depths within the Project Site for the 100-year storm. Table 3 –100-Year Flood Depths Onsite Peak Flow Depth (ft) Percentage of Project Area Covered by Peak Flow Depths 0.00 - 0.49 98.6% 0.50 - 1.00 0.9% 1.01 - 1.50 0.1% 1.51 - 2.00 0.1% 2.01 - 2.50 0.1% 2.51 - 3.00 <0.1% 3.01 - 4.00 0.2% 4.01 - 6.00 <0.1% 6.01+ <0.1% See Exhibits 6 through 7A for areas within the Project with higher flood depths and velocities for the 100-year storm. During the 10-year storm, flood depths are minimized when compared with the 100-year storm, although flooding locations are expected to be generally the same. The vast majority of the project will see flood depths and velocities less than 0.5 feet and 1 foot/second respectively. See Table 4 below for a breakdown of flood depths within the Project Site for the 100-year storm. Hydrology Study | Eagle Springs Solar Project February 28, 2023 7 | Confidential and Proprietary. TBPLS Firm #10074302 Table 4 –10-Year Flood Depths Onsite Peak Flow Depth (ft) Percentage of Project Area Covered by Peak Flow Depths 0.00 - 0.49 99.4% 0.50 - 1.00 0.2% 1.01 - 1.50 <0.1% 1.51 - 2.00 0.2% 2.01 - 2.50 <0.1% 2.51 - 3.00 0.2% 3.01 - 4.00 <0.1% 4.01 - 6.00 <0.1% 6.01+ <0.1% See Exhibits 9 through 10A for areas within the Project with higher flood depths and velocities for the 10-year storm. During the 500-year storm, increased rainfall leads to high flood depths and velocities across the Project Area. Compared to the 100-year, there is an increase in areas that are inundated with flood depths greater than 0.5 feet, such as the areas behind the berms, where depths can reach up to 3.5 feet at certain locations. See Table 5 below for a breakdown of flood depths within the Project Site for the 100- year storm. Hydrology Study | Eagle Springs Solar Project February 28, 2023 8 | Confidential and Proprietary. TBPLS Firm #10074302 Table 5 –500-Year Flood Depths Onsite Peak Flow Depth (ft) Percentage of Project Area Covered by Peak Flow Depths 0.00 - 0.49 97.4% 0.50 - 1.00 1.8% 1.01 - 1.50 0.4% 1.51 - 2.00 <0.1% 2.01 - 2.50 0.2% 2.51 - 3.00 <0.1% 3.01 - 4.00 0.2% 4.01 - 6.00 <0.1% 6.01+ <0.1% See Exhibits 12 through 13A for areas within the Project with higher flood depths and velocities for the 10-year storm. Overall, minimal flooding and velocities are expected within the Project Area. Mamm Creek, which flows adjacent to the Project Area downhill, is not expected to pose hydrologic risk to the Site, even during large storm events. 6.2 Scour Minimal scour is expected onsite (Exhibits 8, 9, and 14). The scour depths calculated for this Project are based on HEC-18 Pier Scour Equations of a 6-inch- wide pile perpendicular to flow. Scour calculations consist of local scour only with unarmored soils and pile bases to provide the conservative local scour results. These scour results do not account for general, rill, or gully scour. 7.0 Recommendations Based on experience on similar projects, the Site is suitable for the planned development and hydrologic concerns can be addressed by either avoiding areas of high flood depths or through detailed engineering design. Hydrology Study | Eagle Springs Solar Project February 28, 2023 9 | Confidential and Proprietary. TBPLS Firm #10074302 8.0 Next Steps 1. Final engineering design should account for the flood depths and velocities presented in Exhibits 6-7A. 2. Facilities to be elevated 1’ above the 100-year, 24-hour peak flood elevations. 3. Stormwater management should be revisited to ensure the final design meets the local and state requirements. Hydrology Study | Eagle Springs Solar Project February 28, 2023 10 | Confidential and Proprietary. TBPLS Firm #10074302 9.0 Included Output Files 1. Shapefile of 500-year Rain Event Flow Depth 2023-01-10_Eaglesprings_FlowDepthatCell_500yr.shp Attribute “ID” = Grid Cell Number Attribute “VAR” = Max Flow Depth (Feet) 2. Shapefile of 500-year Rain Event Velocity 2023-01-10_Eaglesprings_VelocityatCell_500yr.shp Attribute “ID” = Grid Cell Number Attribute “VAR” = Max Velocity (Feet) 3. Shapefile of 100-Year Rain Event Flow Depth 2023-01-10_Eaglesprings_FlowDepthatCell_100yr.shp Attribute “ID” = Grid Cell Number Attribute “VAR” = Max Flow Depth (Feet) 4. Shapefile of 100-Year Rain Event Velocity 2023-01-10_Eaglesprings_VelocityatCell_100yr.shp Attribute “ID” = Grid Cell Number Attribute “VAR” = Max Velocity (Feet) 5. Shapefile of 10-Year Rain Event Flow Depth 2023-01-10_Eaglesprings_FlowDepthatCell_10yr.shp Attribute “ID” = Grid Cell Number Attribute “VAR” = Max Flow Depth (Feet) 6. Shapefile of 10-Year Rain Event Velocity 2023-01-10_Eaglesprings_VelocityatCell_10yr.shp Attribute “ID” = Grid Cell Number Attribute “VAR” = Max Velocity (Feet) 7. KMZ of FLO-2D Results 2023-01-13_Eaglesprings_FLO-2D.kmz Overlay in Google Earth for graphical representation. Hydrology Study | Eagle Springs Solar Project February 28, 2023 11 | Confidential and Proprietary. TBPLS Firm #10074302 10.0 References Cited National Engineering Handbook, Part 630 Hydrology. Chapter 9 Hydrologic Soil-Cover Complexes. USDA. NRCS. 210-VI-NEH, July 2004 The National Map, 1-meter DEM, Elevation data, Accessed January 2023, from https://viewer.nationalmap.gov/basic/ Web soil survey. Retrieved January 2023, from https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx NOAA Atlas 14 Point Precipitation Frequency Estimates. Retrieved January 2023 from https://hdsc.nws.noaa.gov/hdsc/pfds/ USGS. USGS water resources: About USGS water resources. Retrieved January 2023, from https://water.usgs.gov/GIS/huc.html USDA 2021 Cropland Data Layer, Landcover data, retrieved January 2023, from https://www.nass.usda.gov/Research_and_Science/Cropland/Release/ FEMA Flood Insurance Rate Maps, retrieved January 2023, from https://msc.fema.gov/portal/advanceSearch#searchresultsanchor Garfield County Land Use and Development Code, retrieved January 2023, from LUDC-Complete-05.11.2020.pdf (garfield-county.com) Exhibits westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project± 0 8,000 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 01-Location Map - Location Map | 2/28/2023 1:18 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 1: Location Map Legend Project Area FLO-2D Boundary County Boundary Rifle Gap Reservoir 13 13 H ighway 6 H i g h way 1 3 Rifle Colorado River Highway 6 Highway 6 Garfield County Regional Airport Antlers Silt Hi gh way6New Castle Garfield Mesa 6 13 139 70 Curecanti National Recreation Area Uncompahgre National Forest Dinosaur National Monument Grand Junction San Isabel National Forest Routt National Forest White River National Forest Delta EagleGarfield Gunnison Jackson Mesa Moffat Montrose Pitkin Rio Blanco Routt Grand Uintah -Project Location AZ CO KS NE NM OK TX UT WY -Project Location westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project ± 0 6,500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 02-Base Hydrologic Map - USGS, FEMA, and NWI Wetlands Map | 2/28/2023 1:18 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 2: Base Hydrologic Map Legend Project Area FLO-2D Boundary HUC-12 Boundary County Boundary FEMA Zone A FEMA Zone AE NWI Wetlands NHD Flowlines Mi d d l e t o n C r e e k Rising Sun Ditch Salt CreekWest ProngAlkaliCreekEast Mamm CreekNor t h F o r k Che n e y C r e e k Salt CreekRifle CreekPorter DitchWes t D iv ide C reek D i tch Last Chance Ditch U h l C r e e k Mamm CreekHi g h l i n e D i t c h West M a m m Cr e e k Cheney Cree k Sheep Creek Divide CreekCollier CreekTepeeCreekBrush CreekColorad o Ri v er Dry Hollow CreekAlkali CreekMiddle Mamm CreekBeaver CreekDry CreekMi n e o t a D i t c h East For k Br u s h Cr e e k GrandTunnelDitchWare and Hin d s D i t c h West Divide CreekPioneer Ditch Multa Trina DitchEast Divide CreekDiv ideCreekGovernmentCreekR i f l e C r e e k C a n y o n D i t c h Lower Cactus Valley Ditch Garfield Mesa westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project ± 0 6,500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 03-Soils Map - Soils Map | 2/28/2023 1:18 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 3: Soils Map Legend Project Area FLO-2D Boundary County Boundary Hydrologic Soil Group A A/D B C C/D D Water 13 6 70 Rifle Colorado R iver 6 70 Garfield County Regional Airport Antlers Silt Garfield Mesa westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project ± 0 6,500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 04-Landcover Map - Landcover | 2/28/2023 1:19 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 4: Landcover Map Legend Project Area FLO-2D Boundary County Boundary Landcover Barren Cultivated Developed Fallow Woods Pastureland Shrubland Water 13 6 70 Rifle Colorado R iver 6 70 Garfield County Regional Airport Antlers Silt Garfield Mesa westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project ± 0 6,500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 05-CN And Topo Sources - CN and Topo Sources | 2/28/2023 1:18 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 5: Curve Number and Topographic Source Map Legend Project Area FLO-2D Boundary 1m TNM Topo Coverage County Boundary Curve Number 40 - 49 50 - 59 60 - 69 70 - 79 80 - 89 90 - 99 13 6 70 Rifle Colorado R iver 6 70 Garfield County Regional Airport Antlers Silt Garfield Mesa westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project± 0 6,500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 06-100 Yr Max Water Depth Map - 100 Yr Max Water Depth | 2/28/2023 1:18 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 6: 100-Year Max Water Depth Map Legend Project Area FLO-2D Boundary HUC-12 Boundary County Boundary FEMA Zone A FEMA Zone AE NHD Flowlines FLO-2D Culvert Inputs Max Water Depth (ft) 0.50 - 1.00 1.01 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 - 6.00 6.01 + 13 6 70 Rifle Colorado R iver 6 70 Garfield County Regional Airport Antlers Silt Mi d d l e t o n C r e e k Rising Sun Ditch Salt CreekWest ProngAlkaliCreekEast Mamm CreekNor t h F o r k Che n e y C r e e k Salt CreekRifle CreekPorter DitchWes t D iv ide C reek D i tch Last Chance Ditch U h l C r e e k Mamm CreekHi g h l i n e D i t c h West M a m m Cr e e k Cheney Cree k Sheep Creek Divide CreekCollier CreekTepeeCreekBrush CreekColorad o Ri v er Dry Hollow CreekAlkali CreekMiddle Mamm CreekBeaver CreekDry CreekMi n e o t a D i t c h East For k Br u s h Cr e e k GrandTunnelDitchWare and Hin d s D i t c h West Divide CreekPioneer Ditch Multa Trina DitchEast Divide CreekDiv ideCreekGovernmentCreekR i f l e C r e e k C a n y o n D i t c h Lower Cactus Valley Ditch Garfield Mesa westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) Exhibit 6A: 100-Year Max Water Depth Project Area Map February 28, 2023 Garfield County, ColoradoEagle Springs Solar Project ±0 500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx06A-100 Yr Max Water Depth Project Area Map - 100 Yr Max Water Depth Project Area | 2/28/2023 1:17 PM | TPGlaza© 2023 Westwood Legend Project Area FLO-2D Boundary HUC-12 Boundary County Boundary 10' Contours NHD Flowlines Max Water Depth (ft) 0.50 - 1.00 1.01 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 - 6.00 6.01 + Co unt y Road 34 6 MammCre e kR d C o u n t y R o a d352Ri singSunD itch La st C h an ce Ditch70 County R o ad 3 46 M ulta Trina DitchEagle Springs Ranch Rd Ma mm C reek Rd 5670 ft 5660 ft 5640 f t 5630 f t 5610 f t 5600 f t 5590 ft 5550 ft 5500 ft 5520 ft 5480 ft 5450 ft 5400 ft 5390 ft 556 0 f t 5490 f t 5460 ft 5440 ft 5430 ft 5600 ft 5590 ft5580 ft5570 ft 5560 ft 5550 f t 5540 f t 5520 ft 5510 f t 5 5 5 0 f t5520 f t 5570 ft 5550 ft 5500 ft 5460 ft 5 5 2 0 f t 5 4 9 0 f t 565 0 f t 5 6 2 0 f t 5570 ft 5530 f t 5510 ft 5410 ft 5420 ft 538 0 f t 54 7 0 f t5540 ft5580 ft5530 ft550 0 f t 549 0 f t 5480 ft5470 ft 5470 ft 5600 ft5590 ft56 7 0 f t 55 2 0 f t 5 4 0 0 f t 5680 f t 5540 ft 5500 ft 541 0 f t 5380 ft5380 ft 5390 ft Mamm Creek Rising Sun Ditch Mu l t a T r i n a D i t c h Ma m m C r e e k Last Chance Ditch westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project ± 0 6,500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 07-100 Yr Peak Velocity Map - 100 Yr Peak Velocity | 2/28/2023 1:17 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 7: 100-Year Peak Velocity Map Legend Project Area FLO-2D Boundary County Boundary FLO-2D Culvert Inputs Peak Velocity (fps) 1.00 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 + 13 6 70 Rifle Colorado R iver 6 70 Garfield County Regional Airport Antlers Silt Garfield Mesa westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) Exhibit 7A: 100-Year Peak Velocity Project Area Map February 28, 2023 Garfield County, ColoradoEagle Springs Solar Project ±0 500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx07A-100 Yr Peak Velocity Project Area Map - 100 Yr Peak Velocity Project Area | 2/28/2023 1:18 PM | TPGlaza© 2023 Westwood Legend Project Area FLO-2D Boundary County Boundary 10' Contours Peak Velocity (fps) 1.00 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 + Co unt y Road 34 6 MammCre e kR d C o u n t y R o a d352Ri singSunD itch La st C h an ce Ditch70 County R o ad 3 46 M ulta Trina DitchEagle Springs Ranch Rd Ma mm C reek Rd 5670 ft 5660 ft 5640 f t 5630 f t 5610 f t 5600 f t 5590 ft 5550 ft 5500 ft 5520 ft 5480 ft 5450 ft 5400 ft 5390 ft 556 0 f t 5490 f t 5460 ft 5440 ft 5430 ft 5600 ft 5590 ft5580 ft5570 ft 5560 ft 5550 f t 5540 f t 5520 ft 5510 f t 5 5 5 0 f t5520 f t 5570 ft 5550 ft 5500 ft 5460 ft 5 5 2 0 f t 5 4 9 0 f t 565 0 f t 5 6 2 0 f t 5570 ft 5530 f t 5510 ft 5410 ft 5420 ft 538 0 f t 54 7 0 f t5540 ft5580 ft5530 ft550 0 f t 549 0 f t 5480 ft5470 ft 5470 ft 5600 ft5590 ft56 7 0 f t 55 2 0 f t 5 4 0 0 f t 5680 f t 5540 ft 5500 ft 541 0 f t 5380 ft5380 ft 5390 ft westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) Exhibit 8: 100-Year Scour Map February 28, 2023 Garfield County, ColoradoEagle Springs Solar Project ±0 500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx08-100 Yr Scour Map - 100 Yr Scour | 2/28/2023 1:11 PM | TPGlaza© 2023 Westwood Legend Project Area FLO-2D Boundary County Boundary 10' Contours Scour 0.50 - 1.00 1.01 - 1.50 1.51 - 2.00 2.01 + Co unt y Road 34 6 MammCre e kR d C o u n t y R o a d352Ri singSunD itch La st C h an ce Ditch70 County R o ad 3 46 M ulta Trina DitchEagle Springs Ranch Rd Ma mm C reek Rd 5670 ft 5660 ft 5640 f t 5630 f t 5610 f t 5600 f t 5590 ft 5550 ft 5500 ft 5520 ft 5480 ft 5450 ft 5400 ft 5390 ft 556 0 f t 5490 f t 5460 ft 5440 ft 5430 ft 5600 ft 5590 ft5580 ft5570 ft 5560 ft 5550 f t 5540 f t 5520 ft 5510 f t 5 5 5 0 f t5520 f t 5570 ft 5550 ft 5500 ft 5460 ft 5 5 2 0 f t 5 4 9 0 f t 565 0 f t 5 6 2 0 f t 5570 ft 5530 f t 5510 ft 5410 ft 5420 ft 538 0 f t 54 7 0 f t5540 ft5580 ft5530 ft550 0 f t 549 0 f t 5480 ft5470 ft 5470 ft 5600 ft5590 ft56 7 0 f t 55 2 0 f t 5 4 0 0 f t 5680 f t 5540 ft 5500 ft 541 0 f t 5380 ft5380 ft 5390 ft westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project± 0 6,500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 09-10 Yr Max Water Depth Map - 100 Yr Max Water Depth | 2/28/2023 1:16 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 9: 10-Year Max Water Depth Map Legend Project Area FLO-2D Boundary HUC-12 Boundary County Boundary FEMA Zone A FEMA Zone AE NHD Flowlines FLO-2D Culvert Inputs Max Water Depth (ft) 0.50 - 1.00 1.01 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 - 6.00 6.01 + 13 6 70 Rifle Colorado R iver 6 70 Garfield County Regional Airport Antlers Silt Mi d d l e t o n C r e e k Rising Sun Ditch Salt CreekWest ProngAlkaliCreekEast Mamm CreekNor t h F o r k Che n e y C r e e k Salt CreekRifle CreekPorter DitchWes t D iv ide C reek D i tch Last Chance Ditch U h l C r e e k Mamm CreekHi g h l i n e D i t c h West M a m m Cr e e k Cheney Cree k Sheep Creek Divide CreekCollier CreekTepeeCreekBrush CreekColorad o Ri v er Dry Hollow CreekAlkali CreekMiddle Mamm CreekBeaver CreekDry CreekMi n e o t a D i t c h East For k Br u s h Cr e e k GrandTunnelDitchWare and Hin d s D i t c h West Divide CreekPioneer Ditch Multa Trina DitchEast Divide CreekDiv ideCreekGovernmentCreekR i f l e C r e e k C a n y o n D i t c h Lower Cactus Valley Ditch Garfield Mesa westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) Exhibit 9A: 10-Year Max Water Depth Project Area Map February 28, 2023 Garfield County, ColoradoEagle Springs Solar Project ±0 500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx09A-10 Yr Max Water Depth Project Area Map - 10 Yr Max Water Depth Project Area1 | 2/28/2023 1:16 PM | TPGlaza© 2023 Westwood Legend Project Area FLO-2D Boundary HUC-12 Boundary County Boundary 10' Contours NHD Flowlines Max Water Depth (ft) 0.50 - 1.00 1.01 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 - 6.00 6.01 + Co unt y Road 34 6 MammCre e kR d C o u n t y R o a d352Ri singSunD itch La st C h an ce Ditch70 County R o ad 3 46 M ulta Trina DitchEagle Springs Ranch Rd Ma mm C reek Rd 5670 ft 5660 ft 5640 f t 5630 f t 5610 f t 5600 f t 5590 ft 5550 ft 5500 ft 5520 ft 5480 ft 5450 ft 5400 ft 5390 ft 556 0 f t 5490 f t 5460 ft 5440 ft 5430 ft 5600 ft 5590 ft5580 ft5570 ft 5560 ft 5550 f t 5540 f t 5520 ft 5510 f t 5 5 5 0 f t5520 f t 5570 ft 5550 ft 5500 ft 5460 ft 5 5 2 0 f t 5 4 9 0 f t 565 0 f t 5 6 2 0 f t 5570 ft 5530 f t 5510 ft 5410 ft 5420 ft 538 0 f t 54 7 0 f t5540 ft5580 ft5530 ft550 0 f t 549 0 f t 5480 ft5470 ft 5470 ft 5600 ft5590 ft56 7 0 f t 55 2 0 f t 5 4 0 0 f t 5680 f t 5540 ft 5500 ft 541 0 f t 5380 ft5380 ft 5390 ft Mamm Creek Rising Sun Ditch Mu l t a T r i n a D i t c h Ma m m C r e e k Last Chance Ditch westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project ± 0 6,500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 10-10 Yr Peak Velocity Map - 100 Yr Peak Velocity | 2/28/2023 1:16 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 10: 10-Year Peak Velocity Map Legend Project Area FLO-2D Boundary County Boundary FLO-2D Culvert Inputs Peak Velocity (fps) 1.00 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 + 13 6 70 Rifle Colorado R iver 6 70 Garfield County Regional Airport Antlers Silt Garfield Mesa westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) Exhibit 10A: 10-Year Peak Velocity Project Area Map February 28, 2023 Garfield County, ColoradoEagle Springs Solar Project ±0 500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx10A-10 Yr Peak Velocity Project Area Map - 10 Yr Peak Velocity Project Area1 | 2/28/2023 1:17 PM | TPGlaza© 2023 Westwood Legend Project Area FLO-2D Boundary County Boundary 10' Contours Peak Velocity (fps) 1.00 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 + Co unt y Road 34 6 MammCre e kR d C o u n t y R o a d352Ri singSunD itch La st C h an ce Ditch70 County R o ad 3 46 M ulta Trina DitchEagle Springs Ranch Rd Ma mm C reek Rd 5670 ft 5660 ft 5640 f t 5630 f t 5610 f t 5600 f t 5590 ft 5550 ft 5500 ft 5520 ft 5480 ft 5450 ft 5400 ft 5390 ft 556 0 f t 5490 f t 5460 ft 5440 ft 5430 ft 5600 ft 5590 ft5580 ft5570 ft 5560 ft 5550 f t 5540 f t 5520 ft 5510 f t 5 5 5 0 f t5520 f t 5570 ft 5550 ft 5500 ft 5460 ft 5 5 2 0 f t 5 4 9 0 f t 565 0 f t 5 6 2 0 f t 5570 ft 5530 f t 5510 ft 5410 ft 5420 ft 538 0 f t 54 7 0 f t5540 ft5580 ft5530 ft550 0 f t 549 0 f t 5480 ft5470 ft 5470 ft 5600 ft5590 ft56 7 0 f t 55 2 0 f t 5 4 0 0 f t 5680 f t 5540 ft 5500 ft 541 0 f t 5380 ft5380 ft 5390 ft westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) Exhibit 11: 10-Year Scour Map February 28, 2023 Garfield County, ColoradoEagle Springs Solar Project ±0 500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx11-10 Yr Scour Map - 10 Yr Scour1 | 2/28/2023 1:17 PM | TPGlaza© 2023 Westwood Legend Project Area FLO-2D Boundary County Boundary 10' Contours Scour 0.50 - 1.00 1.01 - 1.50 1.51 - 2.00 2.01 + Co unt y Road 34 6 MammCre e kR d C o u n t y R o a d352Ri singSunD itch La st C h an ce Ditch70 County R o ad 3 46 M ulta Trina DitchEagle Springs Ranch Rd Ma mm C reek Rd 5670 ft 5660 ft 5640 f t 5630 f t 5610 f t 5600 f t 5590 ft 5550 ft 5500 ft 5520 ft 5480 ft 5450 ft 5400 ft 5390 ft 556 0 f t 5490 f t 5460 ft 5440 ft 5430 ft 5600 ft 5590 ft5580 ft5570 ft 5560 ft 5550 f t 5540 f t 5520 ft 5510 f t 5 5 5 0 f t5520 f t 5570 ft 5550 ft 5500 ft 5460 ft 5 5 2 0 f t 5 4 9 0 f t 565 0 f t 5 6 2 0 f t 5570 ft 5530 f t 5510 ft 5410 ft 5420 ft 538 0 f t 54 7 0 f t5540 ft5580 ft5530 ft550 0 f t 549 0 f t 5480 ft5470 ft 5470 ft 5600 ft5590 ft56 7 0 f t 55 2 0 f t 5 4 0 0 f t 5680 f t 5540 ft 5500 ft 541 0 f t 5380 ft5380 ft 5390 ft westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project± 0 6,500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 12-500 Yr Max Water Depth Map - 100 Yr Max Water Depth | 2/28/2023 1:16 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 12: 500-Year Max Water Depth Map Legend Project Area FLO-2D Boundary HUC-12 Boundary County Boundary FEMA Zone A FEMA Zone AE NHD Flowlines FLO-2D Culvert Inputs Max Water Depth (ft) 0.50 - 1.00 1.01 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 - 6.00 6.01 + 13 6 70 Rifle Colorado R iver 6 70 Garfield County Regional Airport Antlers Silt Mi d d l e t o n C r e e k Rising Sun Ditch Salt CreekWest ProngAlkaliCreekEast Mamm CreekNor t h F o r k Che n e y C r e e k Salt CreekRifle CreekPorter DitchWes t D iv ide C reek D i tch Last Chance Ditch U h l C r e e k Mamm CreekHi g h l i n e D i t c h West M a m m Cr e e k Cheney Cree k Sheep Creek Divide CreekCollier CreekTepeeCreekBrush CreekColorad o Ri v er Dry Hollow CreekAlkali CreekMiddle Mamm CreekBeaver CreekDry CreekMi n e o t a D i t c h East For k Br u s h Cr e e k GrandTunnelDitchWare and Hin d s D i t c h West Divide CreekPioneer Ditch Multa Trina DitchEast Divide CreekDiv ideCreekGovernmentCreekR i f l e C r e e k C a n y o n D i t c h Lower Cactus Valley Ditch Garfield Mesa westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) Exhibit 12A: 500-Year Max Water Depth Project Area Map February 28, 2023 Garfield County, ColoradoEagle Springs Solar Project ±0 500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx12A-500 Yr Max Water Depth Project Area Map - 500 Yr Max Water Depth Project Area11 | 2/28/2023 1:16 PM | TPGlaza© 2023 Westwood Legend Project Area FLO-2D Boundary HUC-12 Boundary County Boundary 10' Contours NHD Flowlines Max Water Depth (ft) 0.50 - 1.00 1.01 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 - 6.00 6.01 + Co unt y Road 34 6 MammCre e kR d C o u n t y R o a d352Ri singSunD itch La st C h an ce Ditch70 County R o ad 3 46 M ulta Trina DitchEagle Springs Ranch Rd Ma mm C reek Rd 5670 ft 5660 ft 5640 f t 5630 f t 5610 f t 5600 f t 5590 ft 5550 ft 5500 ft 5520 ft 5480 ft 5450 ft 5400 ft 5390 ft 556 0 f t 5490 f t 5460 ft 5440 ft 5430 ft 5600 ft 5590 ft5580 ft5570 ft 5560 ft 5550 f t 5540 f t 5520 ft 5510 f t 5 5 5 0 f t5520 f t 5570 ft 5550 ft 5500 ft 5460 ft 5 5 2 0 f t 5 4 9 0 f t 565 0 f t 5 6 2 0 f t 5570 ft 5530 f t 5510 ft 5410 ft 5420 ft 538 0 f t 54 7 0 f t5540 ft5580 ft5530 ft550 0 f t 549 0 f t 5480 ft5470 ft 5470 ft 5600 ft5590 ft56 7 0 f t 55 2 0 f t 5 4 0 0 f t 5680 f t 5540 ft 5500 ft 541 0 f t 5380 ft5380 ft 5390 ft Mamm Creek Rising Sun Ditch Mu l t a T r i n a D i t c h Ma m m C r e e k Last Chance Ditch westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) February 28, 2023 Eagle Springs Solar Project ± 0 6,500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx 13-500 Yr Peak Velocity Map - 100 Yr Peak Velocity | 2/28/2023 1:17 PM | TPGlaza © 2023 Westwood Garfield County, Colorado Exhibit 13: 500-Year Peak Velocity Map Legend Project Area FLO-2D Boundary County Boundary FLO-2D Culvert Inputs Peak Velocity (fps) 1.00 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 + 13 6 70 Rifle Colorado R iver 6 70 Garfield County Regional Airport Antlers Silt Garfield Mesa westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) Exhibit 13A: 500-Year Peak Velocity Project Area Map February 28, 2023 Garfield County, ColoradoEagle Springs Solar Project ±0 500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx13A-500 Yr Peak Velocity Project Area Map - 500 Yr Peak Velocity Project Area11 | 2/28/2023 1:17 PM | TPGlaza© 2023 Westwood Legend Project Area FLO-2D Boundary County Boundary 10' Contours Peak Velocity (fps) 1.00 - 1.50 1.51 - 2.00 2.01 - 2.50 2.51 - 3.00 3.01 - 4.00 4.01 + Co unt y Road 34 6 MammCre e kR d C o u n t y R o a d352Ri singSunD itch La st C h an ce Ditch70 County R o ad 3 46 M ulta Trina DitchEagle Springs Ranch Rd Ma mm C reek Rd 5670 ft 5660 ft 5640 f t 5630 f t 5610 f t 5600 f t 5590 ft 5550 ft 5500 ft 5520 ft 5480 ft 5450 ft 5400 ft 5390 ft 556 0 f t 5490 f t 5460 ft 5440 ft 5430 ft 5600 ft 5590 ft5580 ft5570 ft 5560 ft 5550 f t 5540 f t 5520 ft 5510 f t 5 5 5 0 f t5520 f t 5570 ft 5550 ft 5500 ft 5460 ft 5 5 2 0 f t 5 4 9 0 f t 565 0 f t 5 6 2 0 f t 5570 ft 5530 f t 5510 ft 5410 ft 5420 ft 538 0 f t 54 7 0 f t5540 ft5580 ft5530 ft550 0 f t 549 0 f t 5480 ft5470 ft 5470 ft 5600 ft5590 ft56 7 0 f t 55 2 0 f t 5 4 0 0 f t 5680 f t 5540 ft 5500 ft 541 0 f t 5380 ft5380 ft 5390 ft westwoodps.com(888) 937-5150Toll Free Data Source(s): Westwood (2023); Esri WMS Basemap Imagery (Accessed 2023); USGS (2023); FEMA (2023); USDA (2023) Exhibit 14: 500-Year Scour Map February 28, 2023 Garfield County, ColoradoEagle Springs Solar Project ±0 500 Feet N:\0042347.00\_GIS\_Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits\2023-02-28 Eagle Springs Hydro Exhibits.aprx14-500 Yr Scour Map - 500 Yr Scour11 | 2/28/2023 1:11 PM | TPGlaza© 2023 Westwood Legend Project Area FLO-2D Boundary County Boundary 10' Contours Scour (ft) 0.50 - 1.00 1.01 - 1.50 1.51 - 2.00 2.01 + Co unt y Road 34 6 MammCre e kR d C o u n t y R o a d352Ri singSunD itch La st C h an ce Ditch70 County R o ad 3 46 M ulta Trina DitchEagle Springs Ranch Rd Ma mm C reek Rd 5670 ft 5660 ft 5640 f t 5630 f t 5610 f t 5600 f t 5590 ft 5550 ft 5500 ft 5520 ft 5480 ft 5450 ft 5400 ft 5390 ft 556 0 f t 5490 f t 5460 ft 5440 ft 5430 ft 5600 ft 5590 ft5580 ft5570 ft 5560 ft 5550 f t 5540 f t 5520 ft 5510 f t 5 5 5 0 f t5520 f t 5570 ft 5550 ft 5500 ft 5460 ft 5 5 2 0 f t 5 4 9 0 f t 565 0 f t 5 6 2 0 f t 5570 ft 5530 f t 5510 ft 5410 ft 5420 ft 538 0 f t 54 7 0 f t5540 ft5580 ft5530 ft550 0 f t 549 0 f t 5480 ft5470 ft 5470 ft 5600 ft5590 ft56 7 0 f t 55 2 0 f t 5 4 0 0 f t 5680 f t 5540 ft 5500 ft 541 0 f t 5380 ft5380 ft 5390 ft Appendix A NOAA Atlas 14 Precipitation Data 1/6/23, 11:21 AM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=39.5236&lon=-107.6958&data=depth&units=english&series=pds 1/4 NOAA Atlas 14, Volume 8, Version 2 Location name: Silt, Colorado, USA* Latitude: 39.5236°, Longitude: -107.6958° Elevation: 5640.23 ft** * source: ESRI Maps** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA, National Weather Service, Silver Spring, Maryland PF_tabular | PF_graphical | Maps_&_aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 5-min 0.114 (0.089‑0.144) 0.144 (0.113‑0.182) 0.197 (0.154‑0.251) 0.246 (0.191‑0.315) 0.319 (0.241‑0.433) 0.380 (0.279‑0.523) 0.445 (0.316‑0.630) 0.516 (0.350‑0.754) 0.615 (0.402‑0.929) 0.696 (0.440‑1.06) 10-min 0.166 (0.130‑0.211) 0.211 (0.165‑0.267) 0.289 (0.225‑0.368) 0.360 (0.279‑0.461) 0.467 (0.353‑0.634) 0.557 (0.409‑0.765) 0.652 (0.463‑0.923) 0.755 (0.513‑1.10) 0.901 (0.588‑1.36) 1.02 (0.645‑1.56) 15-min 0.203 (0.159‑0.257) 0.257 (0.201‑0.325) 0.353 (0.275‑0.448) 0.439 (0.341‑0.562) 0.570 (0.431‑0.773) 0.679 (0.499‑0.933) 0.795 (0.564‑1.13) 0.921 (0.626‑1.35) 1.10 (0.717‑1.66) 1.24 (0.786‑1.90) 30-min 0.261 (0.204‑0.330) 0.336 (0.263‑0.426) 0.468 (0.365‑0.595) 0.583 (0.452‑0.746) 0.753 (0.567‑1.02) 0.892 (0.654‑1.22) 1.04 (0.735‑1.47) 1.19 (0.810‑1.74) 1.41 (0.919‑2.13) 1.58 (1.00‑2.42) 60-min 0.338 (0.265‑0.428) 0.421 (0.330‑0.534) 0.566 (0.441‑0.719) 0.693 (0.537‑0.886) 0.879 (0.662‑1.18) 1.03 (0.756‑1.41) 1.19 (0.843‑1.68) 1.36 (0.922‑1.98) 1.60 (1.04‑2.40) 1.78 (1.13‑2.72) 2-hr 0.415 (0.328‑0.521) 0.506 (0.399‑0.636) 0.664 (0.522‑0.837) 0.802 (0.627‑1.02) 1.00 (0.762‑1.34) 1.17 (0.865‑1.58) 1.34 (0.959‑1.87) 1.53 (1.05‑2.19) 1.78 (1.17‑2.64) 1.99 (1.27‑2.98) 3-hr 0.482 (0.383‑0.602) 0.567 (0.450‑0.709) 0.717 (0.566‑0.899) 0.850 (0.667‑1.07) 1.05 (0.800‑1.39) 1.21 (0.900‑1.62) 1.38 (0.992‑1.91) 1.56 (1.08‑2.23) 1.82 (1.21‑2.68) 2.03 (1.30‑3.02) 6-hr 0.597 (0.478‑0.740) 0.691 (0.552‑0.857) 0.851 (0.678‑1.06) 0.989 (0.784‑1.24) 1.19 (0.915‑1.55) 1.35 (1.01‑1.79) 1.52 (1.10‑2.07) 1.70 (1.18‑2.38) 1.94 (1.30‑2.81) 2.13 (1.39‑3.13) 12-hr 0.728 (0.588‑0.894) 0.841 (0.678‑1.03) 1.03 (0.830‑1.27) 1.20 (0.956‑1.48) 1.43 (1.11‑1.84) 1.61 (1.22‑2.11) 1.81 (1.32‑2.42) 2.00 (1.41‑2.77) 2.28 (1.54‑3.24) 2.49 (1.64‑3.59) 24-hr 0.870 (0.708‑1.06) 1.00 (0.815‑1.22) 1.23 (0.993‑1.50) 1.42 (1.14‑1.74) 1.69 (1.32‑2.15) 1.91 (1.46‑2.46) 2.13 (1.58‑2.83) 2.37 (1.68‑3.23) 2.69 (1.84‑3.77) 2.94 (1.96‑4.18) 2-day 1.01 (0.831‑1.22) 1.16 (0.951‑1.40) 1.41 (1.15‑1.71) 1.62 (1.32‑1.98) 1.93 (1.53‑2.44) 2.18 (1.68‑2.79) 2.44 (1.82‑3.19) 2.71 (1.94‑3.64) 3.08 (2.13‑4.25) 3.37 (2.27‑4.71) 3-day 1.08 (0.894‑1.30) 1.25 (1.03‑1.51) 1.54 (1.27‑1.86) 1.78 (1.46‑2.16) 2.13 (1.69‑2.66) 2.40 (1.86‑3.04) 2.68 (2.01‑3.47) 2.97 (2.13‑3.94) 3.36 (2.33‑4.58) 3.66 (2.47‑5.06) 4-day 1.15 (0.950‑1.37) 1.33 (1.10‑1.60) 1.64 (1.35‑1.97) 1.90 (1.56‑2.29) 2.27 (1.80‑2.81) 2.55 (1.98‑3.21) 2.84 (2.13‑3.65) 3.14 (2.27‑4.14) 3.54 (2.46‑4.79) 3.84 (2.61‑5.28) 7-day 1.34 (1.12‑1.59) 1.53 (1.28‑1.82) 1.85 (1.54‑2.21) 2.12 (1.75‑2.54) 2.50 (2.00‑3.07) 2.79 (2.18‑3.47) 3.09 (2.34‑3.93) 3.39 (2.47‑4.42) 3.80 (2.67‑5.08) 4.11 (2.82‑5.58) 10-day 1.52 (1.27‑1.79) 1.71 (1.43‑2.02) 2.03 (1.69‑2.40) 2.30 (1.91‑2.73) 2.67 (2.15‑3.27) 2.97 (2.34‑3.67) 3.27 (2.49‑4.13) 3.58 (2.62‑4.63) 3.99 (2.82‑5.29) 4.31 (2.97‑5.79) 20-day 1.99 (1.68‑2.33) 2.21 (1.86‑2.58) 2.57 (2.16‑3.01) 2.86 (2.40‑3.37) 3.28 (2.66‑3.95) 3.59 (2.86‑4.38) 3.91 (3.01‑4.87) 4.24 (3.14‑5.39) 4.67 (3.33‑6.08) 4.99 (3.48‑6.60) 30-day 2.36 (2.01‑2.75) 2.62 (2.23‑3.06) 3.05 (2.58‑3.56) 3.39 (2.85‑3.97) 3.86 (3.14‑4.61) 4.21 (3.36‑5.09) 4.56 (3.53‑5.62) 4.91 (3.65‑6.18) 5.36 (3.85‑6.91) 5.70 (4.00‑7.45) 45-day 2.83 (2.42‑3.28) 3.16 (2.70‑3.66) 3.69 (3.14‑4.28) 4.11 (3.48‑4.78) 4.67 (3.82‑5.53) 5.08 (4.07‑6.09) 5.48 (4.26‑6.69) 5.87 (4.39‑7.31) 6.36 (4.59‑8.10) 6.72 (4.74‑8.69) 60-day 3.23 (2.77‑3.73) 3.63 (3.11‑4.19) 4.25 (3.63‑4.92) 4.75 (4.04‑5.51) 5.40 (4.43‑6.35) 5.87 (4.72‑6.99) 6.32 (4.93‑7.66) 6.76 (5.07‑8.35) 7.29 (5.28‑9.20) 7.67 (5.44‑9.85) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper boundsare not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical 1/6/23, 11:21 AM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=39.5236&lon=-107.6958&data=depth&units=english&series=pds 2/4 Back to Top Maps & aerials Small scale terrain 1/6/23, 11:21 AM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=39.5236&lon=-107.6958&data=depth&units=english&series=pds 3/4 Large scale terrain Large scale map Large scale aerial + – 3km 2mi + – 100km 60mi + – 100km 60mi 1/6/23, 11:21 AM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=39.5236&lon=-107.6958&data=depth&units=english&series=pds 4/4 Back to Top US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring, MD 20910 Questions?: HDSC.Questions@noaa.gov Disclaimer + – 100km 60mi Appendix B Curve Number Table neiengineering.com + 303-431-7895 12600 W Colfax Avenue, Suite C500, Lakewood, CO 80215 Stormwater Management Plan AES Clean Energy – Eagle Springs Solar Project Name: Eagle Springs Solar Project Location: Silt, CO NEI Project Number: 4084.001 Client Name: AES Clean Energy Prepared by: NEI Electric Power Engineering, Inc. 12600 W Colfax Avenue, Suite C500 Lakewood, CO 80215 REV DATE ENG APPVD DESCRIPTION A 03/29/23 JPD RDB ISSUED FOR REVIEW AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. i Table of Contents Table of Contents ...................................................................................................................... i 1.0 Project/Site Information ................................................................................................. 1 1.1 Stormwater Management and Sediment Control .......................................................... 1 1.2 Contact Information/Responsible Parties ..................................................................... 4 1.3 Certification Statement ................................................................................................. 5 1.4 Sequence of Construction Activities ............................................................................. 6 1.5 Allowable Non-Stormwater Discharges ........................................................................ 7 2.0 Stormwater Discharge ................................................................................................... 8 2.1 Surface and Receiving Waters ..................................................................................... 8 2.2 Protected Site Features and Sensitive Areas ............................................................... 8 2.3 Potential Sources of Pollution ...................................................................................... 8 2.4 Materials Handling ....................................................................................................... 9 3.0 Erosion and Sediment Control Measures ....................................................................10 3.1 Perimeter Controls ......................................................................................................13 3.1.1 Vehicle Tracking Control ......................................................................................13 3.1.2 Silt Fence .............................................................................................................13 3.1.3 Earth Dikes/Drainage Swales ..............................................................................13 3.2 Additional Control Measures .......................................................................................13 3.2.1 Concrete Washout Areas .....................................................................................13 3.2.2 Stockpile Management ........................................................................................14 3.2.3 Rolled Erosion Control Product ............................................................................14 3.2.4 Wind Erosion/Dust Control ...................................................................................14 3.2.5 Sediment Control Log ..........................................................................................14 3.2.6 Permanent Seeding .............................................................................................15 4.0 Final Stabilization ..........................................................................................................16 4.1 Removal of Temporary Erosion Control Measures ......................................................16 4.2 Stormwater Permits Close-Out....................................................................................16 5.0 Spill Prevention and Response ....................................................................................16 5.1 Vehicle Maintenance, Fueling, and Storage ................................................................18 5.2 Notification Procedures ...............................................................................................20 6.0 Stormwater Inspections ................................................................................................20 6.1 Inspection Frequency ..................................................................................................20 6.2 Common Compliance Problems..................................................................................21 7.0 Recordkeeping ..............................................................................................................22 AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. ii Appendices .............................................................................................................................23 APPENDIX 1: Site Maps ........................................................................................................23 APPENDIX 2: General CDPS Permit for Stormwater Discharges from Construction Activities ..............................................................................................................................................24 APPENDIX 3: Engineering Reports .......................................................................................25 APPENDIX 4: [RESERVED] ..................................................................................................26 APPENDIX 5: Stormwater Inspection Report Template .........................................................27 APPENDIX 6: Completed Stormwater Inspection Reports .....................................................28 AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 1 1.0 Project/Site Information Project activity includes the construction of a 10 MW AC solar powered electric generation facility with a 20MWh DC Coupled BESS generally located 2.6 miles southwest of Silt, Colorado in Garfield County. The proposed site is approximately 96.12 acres, consisting primarily of agricultural and native grasslands of which the project will utilize approximately 53.9 acres. A vicinity map is provided in Appendix 1. The project site consists of two general area types. The northern and southern areas characterized by farmland, while the central area is native grasslands. The Project is located on a localized high area that sits over 100 feet above Mamm Creek which flows to the west of the Project Area. Several ditches are located across the Site and can convey flows, especially in large storm events. In general, the Site is relatively moderately sloped with grades of less than 4% though there are locations where the slopes reach roughly 6%. Slopes generally flow from southeast to northwest, away from Mamm Creek. The site has approximately 80% vegetative cover as determined by aerial imagery and a site inspection. This construction site activities include the clearing and grubbing of existing undeveloped land, grading of the existing contours, and the construction solar panels and associated electrical equipment. Perimeter Control BMPs will be installed prior to the initiation of the mass clearing/grubbing and grading of the site. Silt fence and a sediment control log will be the primary sediment control BMPs used during the lifespan of all construction activities, until final stabilization is reached. The construction activities at this site will be implemented in three distinct Erosion Prevention and Sediment Control Phases. The first phase includes the initial installation of perimeter controls, sediment control BMPs, and the construction entrance. The second phase includes the bulk of the construction activities and the implementation of internal stormwater management BMPs. The final phase, Phase 3, includes the final stabilization of the site. All sensitive areas shall be marked prior to start of earth disturbance activities. Sensitive areas include the identified wetlands which shall be avoided by construction activities including permanent roads, pads, temporary haul roads, and laydown areas. If any subsurface and/or surface drainage features are altered during construction, they will be restored to pre- construction conditions and drainage patterns. 1.1 Stormwater Management and Sediment Control Erosion Prevention BMPs As the existing site is cleared, grubbed and graded to the proposed contours shown on the construction site plans, erosion prevention BMPs shall be placed throughout the construction site to aid in the prevention of sediment-laden stormwater runoff. These BMPs shall be focused in areas with high potential of erosion, areas preceding infiltration practices, and shall be applied to all steep slopes equal to or greater than 3H:1V. Each erosion prevention measure shall be selected on a site-specific basis and details have been provided on the construction site plans. The plans identify all proposed Erosion Prevention BMPs and the recommended installation, maintenance, and inspection procedures. Examples of Erosion Prevention BMPs are, but are not limited to, surface roughening, temporary seeding, erosion control blankets, turf reinforcement mats, sodding, riprap, outlet protection, dust control, and polyacrylamide (PAM). AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 2 Sediment Control BMPs Sediment Control BMPs are designed to remove some of the sediment accumulated within stormwater runoff, to the best extent practicable. These BMPs help prevent sediment impacts to adjacent properties and waterbodies from stormwater discharges originating from construction sites. Typically, these BMPs are placed near each of the site’s outfalls and are installed prior to clearing and grubbing of the site (before large areas of soil are exposed). However, these BMPs can also be located throughout the construction site and, in these circumstances, are installed after mass grading has occurred. Placement, sizing and modifications of Sediment Control BMPs should be left to the SWMP preparer and/or the Site Engineer. Contractors must consult the SWMP Preparer as listed at the front of this SWMP before making any significant changes to these BMPs. Construction Entrances and Dust Control All access areas into and out of the limits of disturbance, as shown on the construction site plans, are required to be equipped with a construction entrance. The use of this BMP will limit the amount of sediment being transported by construction vehicles onto existing roadways or other impervious areas. Any tracked sediment, along with any attached pollutants, deposited on impervious areas could be washed downstream during the next rain event. Each construction entrance must be installed as shown in the details section of the construction site plans. If a new entrance or exit is required, that is not shown on the plans, install the construction entrance as noted by the construction entrance detail, mark the location on the plans and make a record of this minor modification in the SWMP’s modification log, which is located within one of the appendices of the On-site SWMP. Each stabilized construction entrance should be used in conjunction with Street Sweeping measures if it becomes apparent that sediment is still being tracked onto adjacent impervious areas, even with the use of the construction entrance. During extremely dry conditions, drought, and/or excessive winds, the construction site should be treated for dust control to prevent the suspension of fine sediment particles into the air, being carried offsite, and deposited on adjacent properties or surface waters. This practice may not be directly called out for on the construction site plans. A water tanker used to spray the soil down may be an effective way to prevent excessive dust at a construction site. Water Quality BMPs During Construction Site-specific water quality BMPs (e.g., sediment basins, sediment traps, rock check dams, and rock sediment dikes) must be installed prior to the mass clearing, grubbing and grading of the site, and must be kept in functioning order throughout the lifespan of all construction activities. Each of these BMPs must be maintained and inspected until all areas draining to these BMPs have reached final stabilization, approved by the construction site inspector or the SWMP Preparer, and recorded within the stabilization log located as an appendix of the On-site SWMP. The location, installation procedures, and maintenance procedures for each water quality BMP can be found within the approved construction site plans. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 3 Post-Construction Water Quality Upon final stabilization, the construction site will have to make the transition from temporary BMPs to permanent BMPs. This transition will include removal of the temporary silt fence and establishment of permanent vegetation to treat post-construction runoff. Other Stormwater Management Procedures Based on the nature, conditions, and/or procedures associated with this construction site, the following items must be followed and adopted by all those conducting land disturbing activities at this site: · All construction debris must be stockpiled in designated areas, which have been provided with the proper BMPs to prevent the discharge of pollutants through stormwater runoff form building or other similar materials off-site or into surface waters. · Any additional waste material or stockpile material (i.e., soil and mulch) must also be stored in the designated areas as shown on the Construction Site Plans or as the contractor, responsible for day-day activities at this site, deems appropriate. Silt fence or an approved equal shall surround all stockpiled materials. · All parties conducting work at this construction site must be informed of and make note of pollutant sources, both industrial and construction, at this site, and be informed of all controls and measures the will be implemented to prevent the discharge of these pollutants in stormwater runoff. · Any additional non-stormwater discharges, as referenced in the CGP, should be eliminated or reduced to the maximum extent feasible. All unpreventable non-stormwater discharges shall be treated through the approved stormwater management system before release off- site. Following is a list of allowable non-stormwater discharges: · Fire hydrant flushing · Wash water without detergents · Water used for dust control · Potable water · Building wash down water without detergents · Uncontaminated pavement wash water · Uncontaminated condensation from mechanical equipment · Uncontaminated ground or spring water · Water from foundation of footing drains · Uncontaminated excavation dewatering · Landscape irrigation. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 4 1.2 Contact Information/Responsible Parties Project/Site Name and Location: Eagle Springs Solar Near County Road 315 and 346 Garfield County, Colorado Latitude: 39° 31' 21.00" N; Longitude: 107° 41' 43.08" W Owner Name AES Clean Energy 282 Century Place, Suite 2000, Louisville, CO 80027 SWMP Preparer: NEI Electric Power Engineering 12600 W. Colfax Ave, Suite C-500 Lakewood, CO 80215 (720) 689-9719 Qualified Stormwater Manager: _____________________________ AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 5 1.3 Certification Statement “I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Qualified Stormwater Manager Date AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 6 1.4 Sequence of Construction Activities 1. Contractor shall verify location of buried utilities prior to start of construction. Underground utilities not shown on drawings may exist. 2. Obtain approved set of Construction Drawings. An approved Erosion Control Plan shall be required before the onset of any grading activity. Keep a copy of both items onsite throughout construction. 3. Install storm water inspection box with storm water inspection reports, a copy of the permits, and the approved plans. The inspection box will be placed in a prominent location by the main road and driveway. The inspection records for land disturbing activities must be completed weekly and after each significant rainfall event of one- inch (1”) or greater within twenty-four (24) hours. Extra copies of the inspection report forms should be placed in the inspection box. All inspection records must be retained and signed by the qualified inspector identified in Part II.J.2 of the construction general permit. 4. Install construction entrances prior to any land disturbing activities. 5. Flag construction limits and clear only what is necessary to install silt fencing, silt fence outlets. Immediately stabilize the embankments with rolled erosion control product, mulch and seed. 6. Install all perimeter controls including silt fence and silt fence outlets. 7. Begin rough grading the construction access road to required subgrades. 8. Install the gravel construction access road. 9. Begin clearing and grubbing of the vegetation and demolition of other site items as shown on these plans. 10. Once the temporary sediment control BMPs are stabilized and operational, complete the remainder of the site clearing within the construction limits. 11. Topsoil to be reused in areas to be landscaped or seeded may be stockpiled within the designated stockpile locations as indicated on the drawings. The stockpile locations shall be surrounded on three (3) sides by silt fence with one (1) side open to earth moving equipment. All topsoil, vegetation, debris, and other unsuitable material should be removed from the site to an approved and permitted location. 12. Begin rough grading equipment pads grading plan to required subgrades. 13. Subgrade soils shall be inspected by a geotechnical engineer utilizing proof rolling methods and compacted per the grading specifications prior to the placement of fill material. 14. Use temporary seed as conditions warrant in areas with no current work. 15. Finalize the installation of the access drives (including stone), complete grading, and stabilize all disturbed areas by seeding and mulching. 16. Haul away or dispose of any excess spoils not needed to balance site. If any topsoil is to remain stockpiled, protect with silt fencing around perimeter. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 7 17. Soil stabilization measures shall be initiated as soon as practicable in portions of the site where construction activities have temporarily or permanently ceased, but in no case more than seven (7) or fourteen (14) days (depending on slope) after work has ceased. 18. Seed graded slopes and denuded areas following initial soil disturbance. After final use, the spoils area shall be restored and seeded. 19. Install and repair permanent vegetation across the entirety of the site once access roads have been completed. Use light, tracked equipment for minimum ground disturbance during steel pile and solar panel mounting structure installation. 20. Immediately re-seed areas disturbed during panel installation and trenching of underground electrical utilities. 21. Remove all stockpiles of soil, construction material/debris, construction equipment, etc. From the construction site. 22. Ensure the site has uniform vegetative cover of at least 70% compared to the original undisturbed site 1.5 Allowable Non-Stormwater Discharges Allowable sources of non-stormwater discharges (Part I.A.1.b of the Permit, Appendix 2) must be identified in the Plan. Appropriate measures must be taken to ensure that pollution prevention measures for the non-stormwater component of the discharge are implemented. The non-stormwater discharges associated with this project identified at this time are: 1. Discharges from fire fighting activities 2. Water used to control dust in accordance with Part 3.2.4; 3. Potable water sources, including uncontaminated waterline flushings; 4. Uncontaminated ground water or spring water; 5. Concrete washout water; 6. Landscape irrigation return flow AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 8 2.0 Stormwater Discharge On the central and northern project areas, stormwater discharges to the northwest where it exits either to the north off localized high area or to the west and captured by an impounding structure located west of the Project Area. On the southern area, stormwater discharges to the west and south off the high area before flowing into Mamm Creek. The site does not discharge into a public Municipal Separate Storm Sewer System (MS4). 2.1 Surface and Receiving Waters Several manmade ditches carry flows throughout the project area including the Multa Trina Ditch, Highline Ditch, and Rising Sun Ditch. Mamm Creek is the nearest receiving water, located in the ravine south of the project area. The ultimate receiving water is the Colorado River, approximately 1.5 miles from the project site (see Appendix 3, 2023-01-16 Eagle Springs Preliminary Hydrology Study). 2.2 Protected Site Features and Sensitive Areas There is one fringing wetland located along the existing site access road east of the project area, classified as a freshwater palustrine emergent wetland (PEM) in the wetland study (see Appendix 3, EagleSprings_Wetland-WaterDelineationReport_2022_1014_Final, Section 4.4.2). The wetlands shall be flagged prior to the start of construction and a 35 ft. vegetative buffer shall be maintained with existing vegetation throughout the duration of the project to protect the wetland areas. The installation of posts and pilings from solar panels has traditionally not been considered a wetland impact if they do not significantly alter the wetland function and value. No grubbing or grading will take place within the delineated wetland area. Tracked equipment will be used to minimize ground pressure and soil disturbance. In addition to the single wetland, 5 roadside ditches and 4 irrigation ditches were identified in the Project Area. The ditches mapped in the Project Area are likely non-jurisdictional as stated in the wetland study (see Appendix 3, EagleSprings_Wetland- WaterDelineationReport_2022_1014_Final, Section 4.4.3). 2.3 Potential Sources of Pollution Throughout construction activities, each permittee, contractor, and person responsible for conducting work will need to ensure that sources of pollution are managed to prevent their discharge from the construction site. Expected pollution sources during construction have been identified in Table 1, but due to the nature of construction activities, it is often tough to predict all pollution sources that may appear throughout the life of a construction project. For that reason, the following table has also been provided to help all those performing work at this construction site identify possible sources of pollution. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 9 Potential Sources of Pollution Potential Pollutant Location* Control Measures Sediment Disturbed areas Sediment and erosion controls Diesel Fuel/Gasoline Vehicles, equipment, fuel tanks Drip pans, spill kits Concrete Located adjacent to each construction entrance Concrete Washout Basin Groundwater In and around any trenching activities. Direct water into impoundments such as basins or traps to allow for the sedimentation of the listed pollutants. Trash and construction debris Various Dumpster, Good Housekeeping Antifreeze Vehicles, equipment Drip pans, Secondary Containment Hydraulic Oils/Fluids Areas surrounding equipment and fuel tanks Provide secondary containments, locate in upland areas. Repair leaking and broken hoses. Paints Various Washwater should be contained and is prohibited from being discharged Sanitary Waste Near the construction entrance Service provider to secure units from tipping Maintenance activities involving fertilizers, pesticides, and herbicides Entire site Secondary containment and covered storage of materials Vehicle Tracking of Sediment Site entrance Vehicle tracking control Stormwater runoff subjected to the identified pollution sources must be treated by the appropriate BMPs as directed by this SWMP. If any additional sources of pollution are identified during construction, the person(s) with day-to- day operational control at the site is to add the new source(s) to the table and consult with the SWMP Preparer to properly address this source and to prevent the discharge of its pollutant through stormwater runoff. 2.4 Materials Handling When raw materials, byproducts, finished products, storage tanks, and other materials are stored or handled outdoors, stormwater runoff that comes in contact with the materials can become contaminated. Proactively covering storage and handling areas can be an effective source control for such areas. Coverings can be permanent or temporary and consist of tarp, AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 10 plastic sheeting, roofing, enclosed structures, or other approaches that reduce exposure of materials to precipitation and wind. Uses: Covering is appropriate for areas where solids (e.g., gravel, compost, building materials) or liquids (e.g., oil, gas, tar) are stored, prepared, or transferred. Cover the following areas that are applicable to this construction site: · Loading and Unloading: Loading and unloading operations usually take place at outside storage or staging area on the construction site. Materials may be spilled during transfer between storage facilities and trucks during pumping of liquids, pneumatic transfer of dry chemicals, and mechanical transfer of bags, boxes, drums, or other containers by material handling equipment. · Aboveground Tanks/Liquid Storage: Accidental releases of chemicals from above- ground liquid storage can contaminate stormwater with a variety of pollutants. Several common causes of accidental releases from above-ground storage include: external corrosion and structural failure, problems due to improper installation, spills and overfills due to operator error, failure of piping systems, and leads or spills during pumping of liquids or gases between trucks to a storage facility. · Waste Management: Wastes spilled, leached, or lost from outdoor waste management areas or outside manufacturing activities may accumulate in soils or on other surfaces and be carried away by storm runoff. There is also the potential for liquid wastes from surface impoundments to overflow to surface waters or soak the soil where they can be picked up by runoff. Possible stormwater contaminants include toxic compounds, oil and grease, oxygen-demanding organics, paints and solvents, heavy metals and high levels of suspended solids. Lack of coverage of waste receptacles can result in precipitation seeping through the material and collecting contaminants or the material being blown around the site and into the storm sewer system. Containment sources include waste piles, wastewater and solid waste treatment and disposal, land application sites, dumpsters, or unlabeled drums. · Outside Storage of Materials: Raw materials, intermediate products, byproducts, process residuals, finished products, containers, and materials storage areas can be sources of pollutants such as metals, oils and grease, sediment and other contaminants. Pollutant transport can occur when solid materials wash off or dissolve into water, or when spills or leaks occur. Practice Procedures: · Where practical, conduct operations indoors. If outdoors, then select a temporary or permanent covering to reduce exposure of materials to precipitation and runoff. The type of covering selected depends on a variety of factors such as the type and size of activity being conducted and materials involved. Types of cover range from relatively inexpensive tarps and plastic sheeting to overhead structures 3.0 Erosion and Sediment Control Measures Stormwater Volume and Velocity Control During the implementation of construction activities, all parties performing work at this construction site whose work may affect the implementation of the SWMP must be informed of how to manage stormwater runoff within the construction site and at each outfall. The purpose of this requirement is to control the stormwater volume and velocity at these locations to minimize erosion. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 11 Specifically, each responsible party should be made aware of the practices that have been or should be implemented at the construction site to accomplish these particular stormwater management practices. Below is a list of practices that may be utilized within the disturbed area and at each outfall at construction sites to control stormwater volume and velocity: Volume Control · Limiting the amount of disturbed area and exposed soils · Staging and/or Phasing of the Construction Sequence; · Diverting off-site flow around the construction site; · Controlling the Drainage Patterns within the Construction Site; · Temporary Stabilization of Disturbed Areas. Velocity Control · Surface Roughening and/or other Slope Stabilization Practices; · Level Spreaders, Riprap Plunge Pools and/or other Velocity Dissipation BMPS located at the Construction Site's and Sediment Basin Outfalls. · Use of Rock Checks, Sediment Tubes, Etc. in Temporary Diversions Swales and Ditches. · Use of Erosion Control Blankets, Turf Reinforcement Mats, and other Non-Vegetative BMPs that can be used to Quickly Stabilize Disturbed Areas. The SWMP Preparer/Engineer should approve any modifications (Additional BMPs or Changes to Existing BMPs) to address the management of stormwater volume and velocity prior to implementation. All approved SWMPs that were issued coverage under the CGP should include ample BMPs and other control measures. Soil Exposure, Compaction and Preservation Throughout construction activities, the amount of soil exposed during construction should be kept to a minimum. This may be accomplished by minimizing the amount the disturbed area within the permitted Limits of Disturbance (shown on the approved construction site plans) to only that which is necessary to complete the proposed work. For areas that have already been disturbed and where construction activities will not begin for a period of 14 days or more, temporary stabilization techniques must be implemented. Prior to implementation of any major grading activities, topsoil is to be preserved by placing it in areas designated for stockpiling until final grades are reached. Each stockpile must be equipped with proper sediment and erosion controls to preserve the topsoil and protect adjacent areas from impacts. Once final grades have been reached, the preserved topsoil should be utilized to apply to areas identified for stabilization. Topsoil contains nutrients and organisms that aid in the growth of vegetation. The compaction of soil should also be minimized to the degree practicable during grading activities. This is especially important during the replacement of topsoil to aid in a quick establishment of vegetative cover. Compaction of soil may also reduce rainfall's ability to infiltrate into the soil, increasing the amount of stormwater runoff. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 12 Soil Stabilization Throughout construction activities, soil stabilization techniques are to be initiated as soon as practicable whenever any clearing, grading, excavating, or other land-disturbing activities have permanently or temporarily ceased on any portion of the construction site and will not resume for a period exceeding 14 calendar days. For areas where initiating stabilization measures is infeasible, (e.g., where snow cover, frozen ground, or drought conditions preclude stabilization), initiate vegetative or non-vegetative stabilization measures as soon as practicable. Sediment Discharge Minimization Permittees, Contractors, and all other parties responsible for conducting land-disturbing activities are required to install and maintain all erosion and sediment BMPs that are identified on the approved construction site plans. These BMPs have been designed and approved to address such factors as the amount, frequency, intensity and duration of precipitation, the nature of resulting stormwater runoff, and soil characteristics, including the range of soils particle sizes expected to be present on the construction site. Proper installation, inspection, and maintenance will allow these BMPs to operate at maximum efficiencies in order to minimize sediment discharges to the maximum extent practical. Pollutant Discharge Minimization Permittees, Contractors, and all other parties responsible for conducting land-disturbing activities are required to install, implement, and maintain effective pollution prevention measures to minimize the discharge of pollutants. At a minimum, the following items must be implemented: · Minimize the discharge of pollutants from dewatering trenches and excavations by managing runoff with the appropriate controls. Otherwise these discharges are prohibited; · Minimize the discharge of pollutants from equipment and vehicle washing, wheel wash water, and other wash waters. Wash waters must be treated in a sediment basin or alternative control that provides equivalent or better treatment prior to discharge; · Minimize the exposure of building materials, building products, construction wastes, trash, landscape materials, fertilizers, pesticides, herbicides, detergents, sanitary waste and other materials present on the site to precipitation and to stormwater; and · Minimize the discharge of pollutants from spills and leaks and implement chemical spill and leak prevention and response procedures. Prohibited Discharges Permittees, Contractors, and all other responsible parties for conducting land-disturbing activities are prohibited from discharges of the following items: · Wastewater from washout of concrete, unless managed by an appropriate control; · Wastewater from washout and cleanout of stucco, paint, form release oils, curing compounds and other construction materials; · Fuels, oils, or other pollutants used in vehicle and equipment operation and maintenance; and · Soaps or solvents used in vehicle and equipment washing. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 13 3.1 Perimeter Controls Perimeter control BMPs are the last protection before sediment enters the roadway, storm drains or adjacent properties. Perimeter control BMPs can be the most visible and most vandalized BMPs used on a site of ground disturbance. Perimeter BMPs shall be installed before starting and site grading activities. 3.1.1 Vehicle Tracking Control Vehicle tracking control is a stabilized site access point that helps remove sediment from vehicle tires and reduces tracking of sediment onto paved surfaces. Install stabilized construction entrances for vehicle tracking control prior to any land disturbing activities and remove when there is no longer the potential for vehicle tracking to occur. The construction entrance shall be installed at the location identified on the SWMP. Locate the control measure where frequent vehicle traffic will exit the construction site onto a paved roadway. All construction entrances must have non-woven geotextile fabric between the soil and rock pad. Recycled concrete aggregate is not allowed because concrete dust elevates pH in stormwater. Inspect regularly and maintain vehicle tracking controls throughout construction. If the area becomes clogged with sediment, remove and dispose of excess sediment or replace material with a fresh layer of rock. Any sediment that is tracked onto adjacent roadways shall be cleaned with brooms, shovels (no water washing), or mechanically cleaned with a street vacuum sweeper. 3.1.2 Silt Fence Silt fence is a woven geotextile fabric attached to wooden or steel posts and trenched into the ground. It is used to intercept sheet flow runoff from disturbed areas. Silt fence shall be installed prior to land disturbing activities and shall be removed when the upstream area is stabilized. Silt fence shall be installed at the locations identified on the SWMP. Silt fence is typically installed along the contour of slopes, which is down slope of a disturbed area to accept sheet flow and placed along the perimeter of a construction site. Silt fence is not designed to receive concentrated flow, or to be used a filter fabric. Inspect regularly and maintain silt fence throughout construction. Any section that has a tear, hole, slumping, undercutting or has been bypassed shall be replaced. Accumulated sediment shall be removed before it reaches a depth of 6 inches. 3.1.3 Earth Dikes/Drainage Swales Earth dikes and drainage swales are temporary storm conveyance channels used to divert runoff around slopes or to convey runoff to additional sediment control measures prior to discharge from the site. Continuously inspect and maintain all dikes and swales for stability, compaction and signs of erosion and repair. Inspect side slopes for erosion and damage to erosion control fabric. Stabilize slopes and repair fabric as necessary. Accumulated sediment shall be removed when the sediment has accumulated to ½ of the depth of the dike or swale. 3.2 Additional Control Measures 3.2.1 Concrete Washout Areas A concrete washout area is a specific area for concrete washing activities. It can be an excavation of a pit in the ground, above ground storage area or prefabricated haul-away container. The concrete washout area shall be installed prior to any concrete delivery to the AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 14 construction site; and remove upon termination of use of the washout. Accumulated solid waste, including concrete waste and any contamination soils, must be removed from the site to a designated disposal location. The concrete washout area shall be installed at the locations identified on the SWMP. Line the concrete washout area if the groundwater table is high; or if the concrete washout area will be placed within 400 ft of a natural drainage pathway/waterbody; or within 1,000 ft of a wells or drinking water source. Inspect regularly and maintain concrete washout area throughout construction. Ensure adequate signage is in place identifying the location. Remove concrete waste when filled to about ⅔ of capacity to maintain functionality. 3.2.2 Stockpile Management Stockpiles include measures to minimize erosion and sediment transport. Stockpiles shall be used when soils or other erodible materials are stored. Stockpile locations shall be determined during construction. If temporary removal of a control measure is necessary to access the stockpile, ensure control measures area re-installed per detail drawing. When a stockpile is no longer needed, properly dispose of excess materials and re-vegetate or stabilize the ground surface where the stockpile was located. Stockpile locations shall be placed away from areas where concentrated stormwater flow is anticipated, major drainageways, gutters, and storm sewer inlets. Stockpile locations shall be noted on the SWMP. Stockpiles shall be installed with silt fence on three sides, with the opening in the upstream direction. Inspect regularly and maintain the stockpile throughout construction. 3.2.3 Rolled Erosion Control Product Rolled erosion control product (RECP) consists of a variety of temporary or permanently installed manufactured products designed to control erosion and enhance vegetation establishment and survivability, especially on slopes and in channels. Categories of RECP: mulch control netting, open weave textile, erosion control blanket, and turf reinforcement mat. Continuously inspect and maintain all RECP throughout construction. Check for signs of erosion, including voids under the mat. Also check for damaged or loose stakes and secure loose sections of the blanket. 3.2.4 Wind Erosion/Dust Control Dust Control helps keep sediments (from soils and stockpiles) from entering the air as a result of land disturbing construction activities. Implement dust control during conditions which result in dust from either construction activities or from naturally occurring winds. Do not overwater. Apply water or magnesium chloride, seed and mulch or use spray-on soil binders on disturbed areas. Water and magnesium chloride shall be applied such that concentrated flows do not form. 3.2.5 Sediment Control Log A sediment control log is a linear roll made of natural materials such as straw, coconut fiber, or other fibrous material trenched into the ground and held with a wooden stake. Sediment control AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 15 logs are also often referred to as "straw wattles." They are used as a sediment barrier to intercept sheet flow. Be aware that sediment control logs will eventually degrade. Remove accumulated sediment before the depth is one-half the height of the sediment log and repair damage to the sediment log, typically by replacing the damaged section. Once the upstream area is stabilized, remove and properly dispose of the logs. Areas disturbed beneath the logs may need to be seeded and mulched. Sediment control logs that are biodegradable may occasionally be left in place (e.g., when logs are used in conjunction with erosion control blankets as permanent slope breaks). However, removal of sediment control logs after final stabilization is typically recommended when used in perimeter control, inlet protection and check dam applications.. 3.2.6 Permanent Seeding Permanent seeding should be used to stabilize areas at final grade that will not be otherwise stabilized. Effective seeding includes preparing a seedbed, selecting an appropriate seed mixture, using proper planting techniques, and protecting the seeded area with mulch, geotextiles, or other appropriate measures. To provide vegetative cover on disturbed areas that have reached final grade, a perennial grass mix should be established. Permanent seeding should be performed promptly (typically within 14 days) after reaching final grade. Each site will have different characteristics and a landscape professional or the local jurisdiction should be contacted to determine the most suitable seed mix for a specific site. In lieu of a specific recommendation, one of the perennial grass mixes appropriate for site conditions and growth season listed in seed mix tables in the USDCM Volume 2 Revegetation Chapter can be used. The pure live seed (PLS) rates of application recommended in these tables are considered to be absolute minimum rates for seed applied using proper drill-seeding equipment. The below seed mix table and additional background on the site specific reclamation method can be found in Appendix 3, Eagle Springs Organic-Vegetation Management and Reclamation Plan-Final_03-22-2023 Table 3-1. Seed Mix and Application Rates (Upland Mix) Common Name Scientific Name Cultivar % of Seed Mix Pure Live Seed (lb/ac)* Blue Grama Bouteloua gracilis Hachita 20 2.14 Western Wheatgrass Pascopyrum smithii Arriba 20 13.84 Galleta Grass Pleuraphis jamesii Viva 15 8.73 Indian Ricegrass Achnatherum hymenoides Nezpar 10 3.96 Thickspike Wheatgrass Elymus lanceolatus lanceolatus Critana 10 6.05 Western Yarrow Achillea millefolium occidentalis Wild 10 0.21 White Sage Artemisia ludoviciana Wild 5 0.06 White Prairie Clover Dalea candida Wild 5 1.48 Canada Wildrye Elymus canadensis Wild 5 3.54 AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 16 Common Name Scientific Name Cultivar % of Seed Mix Pure Live Seed (lb/ac)* Total 100 40 * lb/ac = pounds per acre, Assumes drill seeding and 40 PLS lbs Per Acre. Sources: CDA 2023; Western Native Seed 2023b. 4.0 Final Stabilization Final Stabilization means that all land disturbing activities are complete, and all disturbed areas have either been built on, paved over or a uniform vegetative cover has been established per SWMP. Prior to closing the State and County Stormwater Permit, all the items listed below must be completed in order for the construction site to be considered to have final stabilization. 1. The site has a uniform vegetative cover with a density of at least 70% compared to the original undisturbed site. Such cover must be capable of adequately controlling soil erosion. 2. If applicable, proper installation and maintenance of all approved, permanent, post-construction stormwater quality treatment drainage facilities. 3. Removal of all stockpiles of soil, construction material/debris, construction equipment, etc. from the construction site. 4. Streets, parking lots and other surrounding paved surfaces are clean and free of any sediment or debris. 5. Removal of sediment, debris or other pollutants within the private and adjacent public storm drainage system. 6. Restoration of any damaged public infrastructure caused by the construction activities. 4.1 Removal of Temporary Erosion Control Measures Once the site has met the final stabilization conditions, the remaining temporary control measures such as perimeter controls, inlet protection, silt fence, etc. shall be removed and disposed of properly. 4.2 Stormwater Permits Close-Out Submit the CDPS Stormwater Discharge Permit Inactivation Form to the State of Colorado, CDPHE. 5.0 Spill Prevention and Response Spills and leaks of solid and liquid materials processed, handled or stored outdoors can be a source of stormwater pollution. Spilled substances can reach receiving waters when runoff washes these materials from impervious surfaces or when spills directly enter the storm system during dry weather conditions. Effective controls depend on spill prevention and response measures, proper training, and may include structural spill containment or control devices. Spill containment measures include temporary or permanent curbs that surround a potential spill site. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 17 Spill control devices include valves, slide gates, or other devices that can control and contain spilled material. Spill Prevention Measures · Train key employees in plan and provide clear, common-sense spill prevention practices and clean-up procedures to be strictly followed. · Identify equipment that is exposed to precipitation, pollutants that may be generated and possible sources of leaks or discharges. · Perform inspections and preventative maintenance of equipment for proper operation and to check for leaks or evidence of discharge (stains). Ensure repairs are completed or provide temporary leak containment until such repairs can be made. · Drain used motor oil and other automotive fluids in a designated area away from storm inlets. Collect spent fluids and recycle or dispose of properly. Never dispose into storm or sanitary sewer. · In fueling areas, clean up spills with dry methods (absorbents) and use damp cloths on gas pumps and damp mops on paved surfaces. · Never hose down a spill or absorbent materials into the storm drain, or down into an interior floor drain which leads to the sanitary sewer system. · Post signs at critical locations with Spill Prevention and Response Plan information. Identification of Spill Areas: Spill prevention and response measures shall be implemented at construction sites in areas where materials may be spilled in quantities that can adversely impact receiving waters or the storm system. Identify potential spill areas, potential spill volumes, material types, frequency of material used, and drainage paths from spill areas with relation to storm sewer inlets, adjacent water bodies, structural CMs, and containment structures. Use this information to determine the types of spill prevention and control measures needed specific to the site conditions. Show the potential spill areas on the EC Plan: · Loading and unloading areas · Outdoor storage areas · Outdoor manufacturing or processing activities · Waste disposal · Areas that generate significant dust or particulates that may later deposit on the ground · Locations where other routine maintenance activities occur Material Handling Procedures: From a water quality perspective, the primary principle behind effective material handling practices is to minimize exposure to precipitation. Store the material indoors, otherwise implement the following outdoor materials handling procedures: · Divert stormwater around materials storage areas. · Keep bulk solid materials (raw materials, sand, gravel, topsoil, compost, concrete, packing materials, metal products, etc) covered and protected from stormwater. · When practical, store materials on impermeable surfaces. · Store hazardous materials according to federal, state, and local requirements. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 18 · Adopt procedures to reduce spills or leaks during filling or transfer of materials. · Substitute less toxic or nontoxic materials for toxic materials. · Store containers that are easily punctured or damaged away from high traffic areas. · Add waste-capture containers such as collection pans for lubricating fluids. · Store drums and containers with liquids on impermeable surfaces. Place drums stored outdoors on pallets to minimize contact with runoff. Spill Response Procedures: Tailor spill response procedures to site-specific conditions and industry-specific regulatory requirements. Follow procedures: · Contain and cleanup spills promptly after the spill is discovered. · Sweep up small quantities of pollutants to reduce exposure to runoff. · Place absorbents at fueling areas or areas susceptible to spills. · Wipe up small spills with a rag, store rags in appropriate containers, dispose of rags properly or use a professional industrial cleaning service. · Contain medium-sized spills with absorbents and absorbent "snakes" as temporary booms for the spill. Store and dispose of absorbents properly. Wet/dry vacuums may be used, but not for volatile fluids. · Install drip pans below minor equipment leaks until a repair can be made. · For large spills, first contain the spill and plug storm inlet where the liquid may migrate off-site, then clean up the spill. · Excavation of spill areas to removed contaminated material may be required where large liquid spills occur on unpaved surfaces. · Maintain an inventory of cleanup materials onsite and strategically locate them based on the types and quantities of chemicals present. · Records of spills, leaks, or overflows that result in the discharge of pollutants must be documented and maintained. 5.1 Vehicle Maintenance, Fueling, and Storage Areas where vehicles are fueled, maintained, and stored/parked can be pollutant "hot spots" that can result in hydrocarbons, trace metals, and other pollutants being transported in precipitation runoff. Proper fueling operations, storage of automotive fluids and effective spill cleanup procedures can help reduce contamination of stormwater runoff from vehicle maintenance and fueling facilities. Fuel-related spills can occur due to lack of attention during fueling or "topping off" fuel tanks. Common activities at construction sites include vehicle fluid replacement and equipment replacement and repair. Some of the wastes generated maintaining automobiles include solvents (degreasers, paint thinners, etc.), antifreeze, brake fluid, brake pad dust, battery acid, motor oil, fuel, and lubricating grease. Practice Procedures for Vehicle Maintenance: The most effective way to minimize wastes generated by automotive maintenance activities is to prevent their production in the first place. The following practices will be implemented: AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 19 · Perform maintenance activities inside or under cover. When repairs cannot be performed indoors, use drip pans or absorbents. · Keep equipment clean and free of excessive oil and grease buildup. · Promptly cleanup spills using dry methods and properly dispose of waste. When water is required, use as little as possible to clean spills, leaks, and drips. · Use a solvent collection service to collect spent solvent used for parts cleaning. · When using liquids for cleaning, use a centralized station to ensure that solvents and residues stay in one area. Locate drip pans and draining boards to direct solvents back into a solvent sink or holding tank for reuse. · Store used oil for recycling in labeled tanks. Locate used oil tanks and drums away from storm sewer, flowing streams, and preferably indoors. · Use non-hazardous or less hazardous alternatives when practical. For example, replace chlorinated organic solvents with non-chlorinated ones like kerosene or mineral spirits. · Properly recycle or dispose of grease, oil, antifreeze, brake fluid, cleaning solutions, hydraulic fluid, batteries, transmission fluid, worn parts, filters, and rags. · Drain and crush oil filters before recycling or disposal. · Drain all fluids and remove batteries from salvage vehicles and equipment. · Closely monitor parked vehicles for leaks and place pans under leaks to collect the fluids for proper disposal or recycling. · Install measures to contain spills and prevent work surface runoff from entering storm sewer system. · Develop a spill prevention plan with measures such as spill kits, and information about location of storm drains and how to protect them if a large spill occurs. · Conduct periodic employee training to reinforce proper disposal practices. · Promptly transfer used fluids to recycling drums or hazardous waste containers. · Store cracked batteries in leak-proof secondary containers. · Inspect outdoor storage areas regularly for drips, spills and improperly stored materials (for example: unlabeled containers, auto parts that might contain grease or fluids, etc). This is particularly important for parking areas for vehicles awaiting repair. · Structural control measures, such as traps, installed in vehicle hotspot areas require routine cleanout of oil and grease. During heavy rainfall, cleanout is required more often to ensure that pollutants are not washed through the trap. Sediment removal is also required on a regular basis to keep the control measure working efficiently. Practice Procedures for Vehicle Fueling: · Fueling areas should be designed to prevent stormwater runoff and spills. Fuel- dispensing areas should be covered with impervious surface, with an adequate slope to prevent ponding, and separated from the rest of the site by a grade break to prevent run-on of precipitation. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 20 · For sites using a mobile fuel truck, establish a designated fueling area. Place temporary "caps" over nearby catch basins or manhole covers so that if a spill occurs, it is prevented from entering the storm sewer. Secondary containment should be used when transferring fuel from the tank truck to the fuel tank. Cover storm drains in the vicinity. Install vapor recovery nozzles to help control drips and reduce air pollution. · Keep spill response information and spill cleanup materials onsite and readily available. · Employ dry cleanup methods cleaning up fuel spills. Such methods include sweeping to remove litter and debris and using rags and absorbents for leaks and spills. · Water should not be used to wash fuel spill areas. During routine cleaning, use a damp cloth on the pumps and a damp mop on the pavement. Fuel dispensing nozzles should be fitted with automatic shutoff except where prohibited by fire department. Post signs at the fuel dispenser warning operators against "topping off' vehicle fuel tanks. 5.2 Notification Procedures The Qualified Stormwater Manager should be notified in the event of a spill. Depending on the nature of the spill and the material involved, the Colorado Department of Public Health and Environment (24-hour spill reporting line – 877-518- 5608), downstream water users, or other agencies may also need to be notified. 6.0 Stormwater Inspections Regular inspections are to be performed by qualified personnel at least once every Seven (7) calendar days and within 24 hours following any runoff producing storm event (0.5” or greater). Inspections shall include the review of all disturbed areas, control measures, and material storage areas. Access points where vehicles enter or exit the site shall be inspected for evidence of offsite sediment tracking onto local roads. Inspections shall be performed monthly for areas that have been stabilized or where stormwater runoff is unlikely due to frozen or snow- covered ground. Inspectors are to utilize the Stormwater Inspection form in Appendix 5 to identify areas where the control measures are inadequate or in need of repair. If the site conditions and/or control measures are found to have changed, the E&SC Plan shall be updated within a period of seven (7) calendar days. If control measures need to be modified to assure effectiveness or if additional measures are determined to be necessary, implementation shall be completed prior to the next anticipated storm event or as soon as practicable. 6.1 Inspection Frequency Inspections shall start within 7 calendar days of commencement of construction activities. Minimum Stormwater Inspection Schedule: A thorough inspection of the site inspection shall be performed in accordance with one of the following minimum frequencies: · At least one inspection every 7 calendar days, or · At least one inspection every 14 calendar days, if post-storm event inspections are conducted within 24 hours after the end of any precipitation or snowmelt event that AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 21 causes surface erosion. Post-storm inspections may be used to fulfill the 14-day routine inspection requirement. Post-Storm Inspections at Temporarily Idle Sites - For permittees choosing to combine 14- day inspections and post-storm-event inspections, if no construction activities will occur following a storm event, post-storm event inspections must be conducted prior to re- commencing construction activities, but no later than 72 hours following the storm event. The delay of any post-storm event inspection must be documented in the inspection record. Routine inspections must still be conducted at least every 14 calendar days. Inspections at Completed Sites/Areas - When the site, or portions of a site are awaiting establishment of a vegetative ground cover and final stabilization, the permittee must conduct a thorough inspection of the stormwater management system at least once every 30 days. Post- storm event inspections are not required under this schedule. This reduced inspection schedule is allowed if all of the following criteria are met: · All construction activities resulting in ground disturbance are complete; · All activities required for final stabilization, in accordance with the SWMP, have been completed, with the exception of the application of seed that has not occurred due to seasonal conditions or the necessity for additional seed application to augment previous efforts; and · The SWMP has been amended to locate those areas to be inspected in accordance with the reduced schedule allowed for in this paragraph. The minimum inspection frequency required does not affect the permittee’s responsibility to implement and maintain effective control measures as prescribed in the SWMP. Proper maintenance may require more frequent inspections. 6.2 Common Compliance Problems The following are problems commonly found at construction sites: · Problem #1 - Not using phased grading or providing temporary or permanent soil stabilization · Problem #2 - No sediment controls on-site · Problem #3 - No sediment control for temporary stockpiles · Problem #4 - No inlet protection · Problem #5 - No control measures or inadequate control measures to minimize vehicle tracking onto the road · Problem #6 - Inadequate or improper solid waste or hazardous waste management · Problem #7 - Unpermitted dewatering and other pollutant discharge at the construction site · Problem #8 - Poorly managed washouts (concrete, paint, stucco) · Problem #9 - Inadequate maintenance of control measures · Problem #10 - Inadequate documentation AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 22 7.0 Recordkeeping The following records shall be kept available at the construction site, or be on-site when construction activities are occurring: · An updated SWMP, reflecting current conditions and CMs. · Keep record of SWMP/EC Plan changes made including the date and identification of the changes (*). · Completed inspection reports, which shall be placed in Appendix 6. · Any document or plan incorporated by reference to the SWMP. SWMP documentation required under this permit are considered reports that must be available to the public under Section 308(b) of the CWA and Section 61.5(4) of the CDPS regulations. The permittee must make plans available to members of the public upon request. However, the permittee may claim any portion of a SWMP as confidential in accordance with 40 CFR Part 2. Records will be retained for a minimum period of at least 3 years after the CDPHE permit is terminated. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 23 Appendices APPENDIX 1: Site Maps AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 24 APPENDIX 2: General CDPS Permit for Stormwater Discharges from Construction Activities AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 25 APPENDIX 3: Engineering Reports 2023-01-16 Eagle Springs Preliminary Hydrology Study EagleSprings_Wetland-WaterDelineationReport_2022_1014_Final Eagle Springs Organic-Geotech Report-Final_03-01-2023 Eagle Springs Organic-Vegetation Management and Reclamation Plan-Final_03-22- 2023 AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 26 APPENDIX 4: [RESERVED] AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 27 APPENDIX 5: Stormwater Inspection Report Template Appendix D from the Colorado Discharge Permit System (CDPS) General Permit COR400000 Stormwater Discharges Associated with Construction Activity AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. 28 APPENDIX 6: Completed Stormwater Inspection Reports © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom © 2023 Microsoft Corporation © 2022 TomTom 70SILTRIFLEWYOMINGNEBRASKAKANSASOKLAHOMANEW MEXICOUTAH7070 SITEGARFIELD COUNTY70DENVERCOLORADO SPRINGSGRAND JUNCTIONFORT COLLINSPUEBLOCOLORADO252576DATEPROJECT TITLE:DESCRIPTIONAPV:PROJECT LOCATION:NO.KEY PLAN:PE STAMP:REVISIONS:SHEET NO:REV:SCALE AT 24" x 36":CHK:DWN:DES:DATE:PROJNUM:SHEET TITLE & DESCRIPTION:2180 South 1300 East, Suite 600Salt Lake City, UT 84106-2749(801) 679 - 3500ELECTRIC POWER ENGINEERING, INC.12600 W. COLFAX AVE, STE. C500LAKEWOOD, CO 80215(303) 431-7895 www.neieng.comCOVER SHEET----FOR PERMITSUBMITTALPENDING GOVERNINGAUTHORITY APPROVALVICINITY MAPSTORMWATER MANAGEMENT PLAN DRAWINGSFOREAGLE SPRINGS ORGANICGARFIELD COUNTY, COLORADOTHE EAGLE SPRINGS ORGANIC SOLAR PROJECT SITE IS LOCATED IN SILT, CO, JUST EAST OF THE RIFLEGARFIELD COUNTY AIRPORT. THE SITE IS A 10 MWAC SOLAR PHOTOVOLTAIC PLUS 20MWH BESS PLANT. THEPLANT WILL BE CONSTRUCTED ON ~96 ACRES OF OPEN LAND. THE COMMERCIAL OPERATION DATE (COD) FORTHE PROJECT IS ANTICIPATED TO BE IN Q4 2024. THE SOLAR POWERPLANT WILL CONSIST OF BIFACIAL SOLARPANELS INSTALLED ON A 2P SINGLE-AXIS TRACKING SYSTEM, ELECTRICAL EQUIPMENT PADS FOR EQUIPMENTSUCH AS TRANSFORMERS AND CENTRAL INVERTERS, AND UNDERGROUND AND OVERHEAD ELECTRICALCIRCUITS. THE PROJECT WILL INTERCONNECT TO HOLY CROSS ENERGY 24.9 KV FEEDER.PER ALTA/NSPS COMPLETED JULY 20,2022 BY ROADRUNNER SURVEY & MAPPING.LEGAL DESCRIPTIONPROJECT DATA AND CODE INFORMATIONPROJECT NAME:EAGLE SPRINGS ORGANICPROJECT ADDRESS:5454 CO ROAD 346SILT, CO 81652 39.5225°, -107.6953°COUNTY:GARFIELD COUNTYCOMMUNITY DEVELOPMENT DEPARTMENT108 8TH STREET, SUITE 401GLENWOOD SPRINGS, CO 81601OWNER NAME:AESLOT SIZE:96.12 ACPROJECT DESCRIPTIONFLOOD ZONE DESIGNATION:THE UNDERGROUND UTILITIES (IF ANY) THAT APPEAR ON THIS MAP HAVE BEEN LOCATED BYFIELD OBSERVATION. THE SURVEYOR MAKES NO GUARANTEE THAT THE UNDERGROUNDUTILITIES SHOWN COMPRISE ALL SUCH UTILITIES IN THE AREA, EITHER IN SERVICE ORABANDONED. THE SURVEYOR FURTHER DOES NOT WARRANT THAT THE UNDERGROUNDUTILITIES SHOWN ARE IN THE EXACT LOCATION INDICATED ALTHOUGH HE DOES STATETHAT THEY ARE LOCATED AS ACCURATELY AS POSSIBLE FROM THE INFORMATIONAVAILABLE.THE PROPERTY SHOWN HEREON LIES IN AN AREA OF UNDETERMINED, BUT POSSIBLE FLOODHAZARD, PER FEMA FIRM MAP PANEL 0802051360B, DATED DECEMBER 15, 1977.UTILITY NOTES:PROJECT TEAMOWNER / APPLICANTAES CLEAN ENERGY282 CENTURY PLACE, SUITE 200LOUISVILLE, CO 80027CONTACT: BENJAMIN DERMERT: 720-646-5224EMAIL: BENJAMIN.DERMER@AES.COMELECTRICAL / STRUCTURAL / CIVILNEI ELECTRICAL POWER ENGINEERING12600 WEST COLFAX AVE., STE 500LAKEWOOD, COLORADO 80215CONTACT: JONATHAN DIMITRIOUEMAIL: JDIMITRIOU@NEIENG.COMPLOTTED: 3/29/2023 4:00 PMH:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\Solar\PV CIV\SWMP Exhibits\ECP-01.01 COVER SHEET.dwgXREFs: ..\..\..\2_Sheetset References\AES Titleblock Outline.dwg; ..\..\2_Sheetset References\ESPR1 - EAGLE SPRINGS_REV2.dwg AES Titleblock 24X36 v210209 EAGLE SPRINGSORGANICSILT, CO4084.001JDJDRDBRDB3/22/23ECP-01.01 AA 3/22/23 ISSUED FOR REVIEW- - -- - -- - -- - -- - -- - -- - -HYDROLOGY STUDYWESTWOOD12701 WHITEWATER DRIVE, SUITE 300MINNETONKA, MN 55343T: (952) 937-5150ALTA SURVEYROADRUNNER SURVEY & MAPPING, INC2130 ROADRUNNER TRL.RIESEL, TX 76682T: (254) 730-7574EMAIL: INFO@RSMROADRUNNER.COMGEOTECHNICAL REPORTTERRACON6949 SOUTH HIGH TECH DRIVEMIDVALE, UTAH 84047T: (801) 545-85000 1,000' 2,000' 3,000' 4,000'1" = 2,000'PARCEL BOUNDARYSITEREGIONAL MAPSITE DATA TABLEPROJECT LOCATIONRIFLE, COLORADOPROPERTY AREA96.12 ACRESALTA SURVEYEAGLE SPRINGS SOLAR SITE PREPARED BY ROADRUNNER SURVEY &MAPPING DATED 11/20/22HYDROLOGY SURVEYEAGLE SPRINGS SOLAR SITE PRELIMINARY HYDROLOGY STUDYPREPARED BY WESTWOOD DATED 01/16/23GEOTECHNICAL SURVEYEAGLE SPRINGS SOLAR SITE GEOTECHNICAL ENGINEERING REPORTPREPARED BY TERRACON DATED 11/15/22VEGETATION MANAGEMENT ANDRECLAMATION PLANEAGLE SPRINGS ORGANIC VEGETATION MANAGEMENT AND RECLAMATIONPLAN PREPARED BY TRC COMPANIES DATED 03/22/23MAMM CREEK RDENVIORNMENTAL CONSULTANTTRC COMPANIES123 N COLLEGE AVE #250,FORT COLLINS, CO 80524T: (970) 484-3263SHEET LISTSHEET NUMBERSHEET TITLEECP-01.01COVER SHEETECP-01.02NOTESECP-01.03PHASE 1 (TEMPORARY)ECP-01.04PHASE 2 (INTERIM)ECP-01.05PHASE 3 (FINAL)ECP-01.07EROSION CONTROL DETAILSECP-01.06EROSION CONTROL DETAILSNN DATEPROJECT TITLE:DESCRIPTIONAPV:PROJECT LOCATION:NO.KEY PLAN:PE STAMP:REVISIONS:SHEET NO:REV:SCALE AT 24" x 36":CHK:DWN:DES:DATE:PROJNUM:SHEET TITLE & DESCRIPTION:2180 South 1300 East, Suite 600Salt Lake City, UT 84106-2749(801) 679 - 3500ELECTRIC POWER ENGINEERING, INC.12600 W. COLFAX AVE, STE. C500LAKEWOOD, CO 80215(303) 431-7895 www.neieng.comNOTES----FOR PERMITSUBMITTALPENDING GOVERNINGAUTHORITY APPROVALGENERAL NOTES1. OBTAIN ALL APPLICATION PERMITS PRIOR TO CONSTRUCTION.3. THE FOLLOWING MUST BE KEPT ON SITE UNTIL THE SWMP HAS BEEN CLOSED OUT BY COLORADO DEPARTMENT OF PUBLIC HEALTH ANDENVIRONMENT (CDPHE): 12 MONTHS OF SELF INSPECTION RECORDS, RAIN GAUGE, APPROVAL CERTIFICATE/LETTER, APPROVED PLANAND NPDES PERMIT. THESE ITEMS SHOULD BE LOCATED NEAR THE MAIN CONSTRUCTION ENTRANCE. FAILURE TO MAINTAIN THESE ITEMSON SITE VIOLATES THE NPDES PERMIT.4. ELECTRICAL EQUIPMENT SHOWN IN THIS DRAWING PACKAGE ARE PROPOSED AND FOR ILLUSTRATIVE PURPOSES ONLY.5. ANY STOCKPILE SHALL HAVE A SURROUNDING SILT FENCE EXCEPT FOR THE INGRESS/EGRESS. (3 SIDES)6. ADD ADDITIONAL SILT FENCING AND SILT FENCE OUTLETS AS NEEDED INSIDE THE DISTURBANCE LIMIT FOR EROSION CONTROL AND SILTFENCE INTEGRITY.7. CONTRACTOR SHALL ENSURE THAT THERE IS PROPER COVER AND PROTECTION OVER ALL CULVERTS.8. CONTRACTOR SHOULD MINIMIZE SUBGRADE DISTURBANCE BY USING LIGHT TRACKED EQUIPMENT.9. PERMANENT GROUND COVER WILL BE PROVIDED FOR ALL DISTURBED AREAS WITHIN 14 WORKING DAYS OR PER NPDES REQUIREMENTS,WHICHEVER IS SHORTER.10. ADDITIONAL PERTINENT EROSION CONTROL MEASURES TO BE DETAILED IN OVERALL SITE GRADING AND EROSION CONTROL PLAN.11. ALL SUBGRADE, FILL, AND STONE SHALL BE COMPACTED AS SPECIFIED IN THE GRADING SPECIFICATIONS.12. 8' TALL WILDLIFE FENCE TO BE DESIGNED AND INSTALLED BY FENCING CONTRACTOR. THE PROPOSED ACCESS GATE WILL BE LOCKEDWITH STANDARD KEYED OR COMBINATION LOCK. EMERGENCY PERSONNEL WILL BE PROVIDED A KEY OR COMBINATION FOR ACCESS.13. NO STRUCTURE SHALL EXCEED A HEIGHT GREATER THAN FIFTEEN (15) FEET, EXCEPT FOR ELECTRICAL TRANSMISSION LINES AND UTILITYPOLES.14. NO LIGHTING IS PROPOSED FOR THIS SITE.15. THE PROPERTY SHOWN HEREON LIES IN AN AREA OF UNDETERMINED, BUT POSSIBLE FLOOD HAZARD, PER FEMA FIRM MAP PANEL0802051360B, DATED DECEMBER 15, 1977.16. UTILITY LINES AND SERVICES SHOWN HEREON ARE APPROXIMATE PER AERIAL PHOTOGRAPHY OR AS REPORTED BY VARIOUSRESPONSIBLE PARTIES. LOCATION OF UNDERGROUND UTILITIES ARE APPROXIMATE AND MUST BE FIELD VERIFIED.17. CLARIFICATIONS CAN BE ADDRESSED BY CONTACTING RYAN BRICK P.E EMAIL: RBRICK@NEIENG.COM / PHONE: (303) 468-3055GRADING PLAN NOTES1. PROJECT LOCATION IS IN GARFIELD COUNTY, COLORADO.2. COORDINATES ARE IN NAD83 COLORADO STATE PLANES, CENTRAL ZONE, US FT.3. CONTRACTOR SHALL FIELD VERIFY ALL LOCAL BENCHMARKS/MONUMENTS PRIOR TO CONSTRUCTION.4. EG IS DENOTED AS EXISTING GRADE.5. IE IS DENOTED AS INVERT ELEVATION OF CULVERT OR SWALE.6. ALL MEASUREMENTS ARE IN FEET, UNLESS SPECIFIED OTHERWISE.7. CUT AND FILL SLOPES SHALL BE 3:1 OR FLATTER UNLESS NOTED OTHERWISE ON THE PLAN SHEET. ALL DISTURBED GROUNDNOT COVERED WITH GRAVEL SHALL BE TEMPORARILY STABILIZED PER THE REQUIREMENTS OF THE STORMWATERPOLLUTION PREVENTION PLAN.8. FINAL STABILIZATION REQUIREMENTS SHALL BE BASED ON THE REQUIREMENTS OF THE STORM WATER POLLUTIONPREVENTION PLAN.9. DIRECTION OF TRAFFIC SHALL BE CONFIRMED BY THE CONTRACTOR PRIOR TO CONSTRUCTION10. THE CONTRACTOR SHALL VERIFY ALL EXISTING CONDITIONS, UTILITIES AND CULVERTS PRIOR TO CONSTRUCTION. THECONTRACTOR SHALL INFORM THE ENGINEER OF ANY DISCREPANCIES BETWEEN THE EXISTING CONDITIONS AND THEPLANS.11. CONTRACTOR TO PROTECT EXISTING UTILITIES AND MAINTAIN EXISTING DRAINAGE PATTERNS AT ALL TIMES.12. CONTRACTOR TO VERIFY RIGHT OF WAY LIMITS PRIOR TO CONSTRUCTION.13. ADDITIONAL GRAVEL OUTSIDE OF WHAT IS SHOWN ON THE PLAN MAY BE NECESSARY.14. AGGREGATE AND EMBANKMENT COMPACTION AND TESTING SHALL BE DONE PER THE CONSTRUCTION NOTES AND THEROAD CONSTRUCTION STANDARDS FROM THE GEOTECHNICAL REPORT.15. EXISTING FEATURES (FENCE, MAILBOX, SIGN, ETC.) THAT ARE DISTURBED AS PART OF THE TEMPORARY IMPROVEMENTSHALL BE REINSTALLED OR REPLACED IN A CONDITION EQUAL TO OR BETTER THAN THE PRECONSTRUCTION CONDITION.16. CULVERT END SECTIONS MUST HAVE 6:1 OR SHALLOWER SLOPE.17. THE CONTRACTOR SHALL BE RESPONSIBLE FOR ALL TRAFFIC CONTROL. TRAFFIC CONTROL SHALL MEET THEREQUIREMENTS OF THE COUNTY AND THE STATE DEPARTMENT OF TRANSPORTATION AND ALL RECOMMENDATIONS IN THEMANUAL ON UNIFORM TRAFFIC CONTROL DEVICES (MUTCD).18. CONTRACTOR SHALL CALL 811, ONE CALL ENTITIES PRIOR TO CONSTRUCTION. ALL HAZARDS SHALL BE ASSESSED PRIOR TOCONSTRUCTION.19. FINAL GRADE TO MAINTAIN POSITIVE (I.E. OFFSET) DRAINAGE ACROSS THE ENTIRE PROJECT SITE UNLESS SPECIFICALLYINDICATED OTHERWISE IN THIS DRAWING PACKAGE.20. ALL GRADING INSIDE THE PROPOSED FENCED AREA SHALL BE CARRIED TO A FIRM SUBGRADE. THE SUBGRADE SHALL NOTBE FROZEN, SATURATED, SOFT, OR UNSTABLE.21. CONSTRUCTION OF EROSION AND SEDIMENT CONTROL DEVICES IS TO BE CARRIED OUT AND THEIR LOCATION IS TO BE ASDESCRIBED IN THE CONSTRUCTION SEQUENCE. CERTAIN DEVICES ARE TO BE CONSTRUCTED BEFORE GRADINGOPERATIONS BEGIN. ALL DEVICES ARE TO BE MAINTAINED DURING CONSTRUCTION AND TEMPORARY ONES REMOVEDAFTERWARD.22. ALL VEGETATION AND DEBRIS SHOULD BE REMOVED FROM THE SITE. ALL SUBGRADE SOILS SHALL BE FREE OF ORGANICMATERIAL, COMPACTED, AND INSPECTED BY AN APPROVED GEOTECHNICAL ENGINEER PRIOR TO THE PLACEMENT OF FILLMATERIAL. ANY MATERIAL TO BE STOCKPILED ON SITE SHALL BE STOCKPILED WITHIN THE CONSTRUCTION LIMITS AND INDESIGNATED AREAS.STABILIZATION REQUIREMENTS1. TEMPORARY STABILIZATION MUST BE IMPLEMENTED FOR EARTH DISTURBING ACTIVITIES ON ANY PORTION OF THE SITEWHERE GROUND DISTURBING CONSTRUCTION ACTIVITY HAS PERMANENTLY CEASED, OR TEMPORARILY CEASED FOR MORETHAN 14 CALENDAR DAYS. TEMPORARY STABILIZATION METHODS MAY INCLUDE, BUT ARE NOT LIMITED TO, TARPS, SOILTACKIFIER, AND HYDROSEED.2. FINAL STABILIZATION IS REACHED WHEN ALL GROUND SURFACE DISTURBING ACTIVITIES AT THE CONSTRUCTION SITE ARECOMPLETE; AND, FOR ALL AREAS OF GROUND SURFACE DISTURBING ACTIVITIES, EITHER A UNIFORM VEGETATIVE COVERWITH AN INDIVIDUAL PLANT DENSITY OF AT LEAST 70 PERCENT OF PRE-DISTURBANCE LEVELS IS ESTABLISHED, OREQUIVALENT PERMANENT ALTERNATIVE STABILIZATION METHODS ARE IMPLEMENTED.3. ALL TEMPORARY CONTROL MEASURES MUST BE REMOVED FROM THE CONSTRUCTION SITE ONCE FINAL STABILIZATION ISACHIEVED, EXCEPT WHEN THE CONTROL MEASURE SPECIFICATION ALLOW THE CONTROL MEASURE TO BE LEFT IN PLACE.EROSION AND SEDIMENTATION CONTROL NOTES1. CONSTRUCTION OF EROSION AND SEDIMENT CONTROL DEVICES IS TO BE CARRIED OUT AS DESCRIBED IN THECONSTRUCTION SEQUENCE AND THEIR LOCATION IS TO BE AS SHOWN ON THE DRAWINGS. CERTAIN DEVICES ARE TO BECONSTRUCTED BEFORE GRADING OPERATIONS BEGIN. ALL DEVICES ARE TO BE MAINTAINED DURING CONSTRUCTION ANDTEMPORARY ONES REMOVED AFTERWARD.2. THE CONTRACTOR SHALL PROVIDE EROSION CONTROL MEASURES AS PLANNED AND SPECIFIED FOLLOWING BESTMANAGEMENT PRACTICES AS OUTLINED BY THE COLORADO DEPARTMENT OF PUBLIC HEALTH & ENVIRONMENT AND BEINGIN CONFORMANCE WITH THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) GENERAL STORMWATERPERMIT. SEE THE PROJECT SITE PLANS AND ASSOCIATED STORMWATER POLLUTION PREVENTION PLAN (SWPPP) FOREROSION CONTROL AND RESTORATION LOCATIONS AND SPECIFICATIONS. UNLESS OTHERWISE NOTED OR MODIFIED INTHE SWPPP/HEREIN, ALL SECTIONS OF THE GENERAL CONDITIONS SHALL APPLY.3. THE CONTRACTOR SHALL BE RESPONSIBLE FOR MAINTAINING THE SWPPP'S AVAILABILITY.4. ALL FIBER ROLLS AND OTHER EROSION CONTROL FEATURES SHALL BE IN-PLACE PRIOR TO ANYEXCAVATION/CONSTRUCTION AND SHALL BE MAINTAINED UNTIL VIABLE TURF OR GROUND COVER HAS BEEN ESTABLISHED.5. ALL DRAINAGE SWALES DISTURBED DURING CONSTRUCTION ACTIVITIES AND NOT COVERED BY ROAD SURFACINGMATERIALS, SHALL BE STABILIZED IN ACCORDANCE WITH THE SWPP PLAN.6. INSPECT SILT FENCE OUTLETS WEEKLY AND AFTER EACH SIGNIFICANT RAINFALL EVENT OF HALF INCH (1/2") OR GREATERWITHIN TWENTY-FOUR (24) HOURS. CLEAR MESH WIRE OF DEBRIS OR OTHER OBJECTS TO PROVIDE ADEQUATE FLOW FORSUBSEQUENT RAINS. TAKE CARE NOT TO DAMAGE OR UNDERCUT THE WIRE MESH DURING SEDIMENT REMOVAL. REPLACESTONE AS NEEDED.7. ADD TEMPORARY SEED AND SINGLE-NET STRAW ROLLED EROSION CONTROL PRODUCT TO ANY DISTURBED SLOPES ASNEEDED.8. ALL BARE SOILS ARE TO BE STABILIZED UNDER CONDITIONS OUTLINED IN THE CURRENT NPDES PERMIT, OR, IF IN ACRITICAL AREA, BY THE END OF THE DAY.9. STABILIZATION WILL BE PROVIDED FOR ALL DISTURBED AREAS WITHIN 14 DAYS AFTER CONSTRUCTION ACTIVITY ISCOMPLETE UNLESS CONSTRUCTION ACTIVITY IS GOING TO RESUME WITHIN 21 DAYS, EXCEPT SLOPES STEEPER THAN3H:1V TO BE STABILIZED WITHIN 7 DAYS.10. SEDIMENT CONTAINMENT DEVICES ARE TO REMAIN IN OPERATING CONDITION UNTIL PERMANENT VEGETATION ISESTABLISHED.EARTHEN STOCKPILE MANAGEMENT1. LOCATE EARTHEN-MATERIAL STOCKPILE AREAS AT LEAST 50 FEET AWAY FROM STORM DRAIN INLETS, SEDIMENT BASINS,PERIMETER SEDIMENT CONTROLS AND SURFACE WATERS UNLESS IT CAN BE SHOWN NO OTHER ALTERNATIVES AREREASONABLY AVAILABLE.2. PROTECT STOCKPILE WITH SILT FENCE INSTALLED ALONG TOE OF SLOPE WITH A MINIMUM OFFSET OF FIVE FEET FROMTHE TOE OF STOCKPILE.3. PROVIDE STABLE STONE ACCESS POINT WHEN FEASIBLE.4. STABILIZE STOCKPILE WITHIN THE TIMEFRAMES PROVIDED ON THIS SHEET AND IN ACCORDANCE WITH THE APPROVEDPLAN AND ANY ADDITIONAL REQUIREMENTS. SOIL STABILIZATION IS DEFINED AS VEGETATIVE, PHYSICAL OR CHEMICALCOVERAGE TECHNIQUES THAT WILL RESTRAIN ACCELERATED EROSION ON DISTURBED SOILS FOR TEMPORARY ORPERMANENT CONTROL NEEDS.CONCRETE WASHOUTS1. DO NOT DISCHARGE CONCRETE OR CEMENT SLURRY FROM THE SITE.2. DISPOSE OF, OR RECYCLE SETTLED, HARDENED CONCRETE RESIDUE IN ACCORDANCE WITH LOCAL AND STATE SOLIDWASTE REGULATIONS AND AT AN APPROVED FACILITY.3. MANAGE WASHOUT FROM MORTAR MIXERS IN ACCORDANCE WITH THE ABOVE ITEM AND IN ADDITION PLACE THE MIXERAND ASSOCIATED MATERIALS ON IMPERVIOUS BARRIER AND WITHIN LOT PERIMETER SILT FENCE.4. INSTALL TEMPORARY CONCRETE WASHOUTS PER LOCAL REQUIREMENTS, WHERE APPLICABLE. IF AN ALTERNATE METHODOR PRODUCT IS TO BE USED, CONTACT YOUR APPROVAL AUTHORITY FOR REVIEW AND APPROVAL. IF LOCAL STANDARDDETAILS ARE NOT AVAILABLE, USE ONE OF THE TWO TYPES OF TEMPORARY CONCRETE WASHOUTS PROVIDED ON THISDETAIL.5. DO NOT USE CONCRETE WASHOUTS FOR DEWATERING OR STORING DEFECTIVE CURB OR SIDEWALK SECTIONS.STORMWATER ACCUMULATED WITHIN THE WASHOUT MAY NOT BE PUMPED INTO OR DISCHARGED TO THE STORM DRAINSYSTEM OR RECEIVING SURFACE WATERS. LIQUID WASTE MUST BE PUMPED OUT AND REMOVED FROM PROJECT.6. LOCATE WASHOUTS AT LEAST 50 FEET FROM STORM DRAIN INLETS AND SURFACE WATERS UNLESS IT CAN BE SHOWNTHAT NO OTHER ALTERNATIVES ARE REASONABLY AVAILABLE. AT A MINIMUM, INSTALL PROTECTION OF STORM DRAININLET(S) CLOSEST TO THE WASHOUT WHICH COULD RECEIVE SPILLS OR OVERFLOW.7. LOCATE WASHOUTS IN AN EASILY ACCESSIBLE AREA, ON LEVEL GROUND AND INSTALL A STONE ENTRANCE PAD IN FRONTOF THE WASHOUT. ADDITIONAL CONTROLS MAY BE REQUIRED BY THE APPROVING AUTHORITY.8. INSTALL AT LEAST ONE SIGN DIRECTING CONCRETE TRUCKS TO THE WASHOUT WITHIN THE PROJECT LIMITS. POSTSIGNAGE ON THE WASHOUT ITSELF TO IDENTIFY THIS LOCATION.9. REMOVE LEAVINGS FROM THE WASHOUT WHEN AT APPROXIMATELY 75% CAPACITY TO LIMIT OVERFLOW EVENTS.REPLACE THE TARP, SAND BAGS OR OTHER TEMPORARY STRUCTURAL COMPONENTS WHEN NO LONGER FUNCTIONAL.WHEN UTILIZING ALTERNATIVE OR PROPRIETARY PRODUCTS, FOLLOW MANUFACTURER'S INSTRUCTIONS.10. AT THE COMPLETION OF THE CONCRETE WORK, REMOVE REMAINING LEAVINGS AND DISPOSE OF IN AN APPROVEDDISPOSAL FACILITY. FILL PIT, IF APPLICABLE, AND STABILIZE ANY DISTURBANCE CAUSED BY REMOVAL OF WASHOUT.GARFIELD COUNTY LAND USE CODES1. CURRENT ZONING IS INDUSTRIAL USE AND A 100' SETBACK IS REQUIRED FORELECTRICAL EQUIPMENT. PER GARFIELD COUNTY LAND USE CODE ZONING 7-1001SECTION B.1.1. AES EAGLE SPRINGS ORGANIC SOLAR, LLC WILL SEEK A WAIVER OF STANDARDS TOTHE 100' SETBACK OF 7-1001 B. IN ITS LAND USE PERMIT - MAJOR IMPACTAPPLICATION GIVEN SAME OWNERSHIP OF ADJACENT PARCELS.2. FENCES MAY BE LOCATED WITHIN THE 100' SETBACK AS PER GARFIELD COUNTY LANDUSE CODE 7-1201 SECTION B.PLOTTED: 3/29/2023 8:42 AMH:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\Solar\PV CIV\SWMP Exhibits\ECP-01.02 NOTES.dwgXREFs: ..\..\..\2_Sheetset References\AES Titleblock Outline.dwg AES Titleblock 24X36 v210209 EAGLE SPRINGSORGANICSILT, CO4084.001JDJDRDBRDB3/22/23ECP-01.02 AA 3/22/23 ISSUED FOR REVIEW- - -- - -- - -- - -- - -- - -- - -CONSTRUCTION SEQUENCEPHASE 11. UNDERGROUND UTILITIES NOT SHOWN ON DRAWINGS MAY EXIST; CONTRACTOR SHALL VERIFY LOCATION OF BURIEDUTILITIES PRIOR TO START OF CONSTRUCTION.2. CONDUCT PRE-CONSTRUCTION CONFERENCE WITH APPROVED ON-SITE SWMP PRIOR TO START OF CONSTRUCTIONACTIVITIES.3. A COPY OF THE SWMP AND THE NOTICE OF COVERAGE (NOC) MUST BE POSTED AT THE SITE PRIOR TO THE START OFCONSTRUCTION ACTIVITIES.4. FLAG CONSTRUCTION LIMITS AND CLEAR ONLY WHAT IS NECESSARY TO INSTALL SILT FENCING AND SILT FENCE OUTLETS.5. INSTALL ALL PERIMETER CONTROLS INCLUDING SILT FENCE AND SILT FENCE OUTLETS.6. AREAS DELINEATED AS TEMPORARY LAYDOWN AREA SHALL BE USED FOR FUEL STORAGE AND DISPENSING, VEHICLE/EQUIPMENT REPAIR, MAINTENANCE AND CLEANING, MATERIALS STORAGE AND HANDLING, AND LOADING/ UNLOADING.7. ONCE PHASE 1 EROSION AND SEDIMENT CONTROL MEASURES HAVE BEEN COMPLETED, PROCEED TO PHASE 2.PHASE 28. INSTALL THE REMAINING EROSION CONTROL MEASURES PRIOR TO THE ONSET OF LAND DISTURBING (INCLUDING DEMO)ACTIVITIES. DISTURB ONLY WHAT IS NECESSARY TO INSTALL THESE MEASURES.9. ONCE THE TEMPORARY SEDIMENT CONTROL BMPs ARE STABILIZED AND OPERATIONAL, COMPLETE THE REMAINDER OFTHE SITE CLEARING WITHIN THE CONSTRUCTION LIMITS.10. THE EXISTING TOPSOIL SHALL BE UNDERCUT AND REMOVED IN THE AREA OF THE PROPOSED SUBSTATION AND SWITCHYARD PADS AND ACCESS DRIVES.11. TOPSOIL TO BE REUSED IN AREAS TO BE LANDSCAPED OR SEEDED MAY BE STOCKPILED WITHIN THE DESIGNATEDSTOCKPILE LOCATION AS INDICATED ON THE DRAWINGS. THE STOCKPILE LOCATION SHALL BE SURROUNDED ON THREE (3)SIDES BY SILT FENCE WITH ONE (1) SIDE OPEN TO EARTH MOVING EQUIPMENT. ALL TOPSOIL, VEGETATION, DEBRIS, ANDOTHER UNSUITABLE MATERIAL SHOULD BE REMOVED FROM THE SITE TO AN APPROVED AND PERMITTED LOCATION.12. BEGIN ROUGH GRADING SITE PER GRADING PLAN TO REQUIRED SUBGRADES.13. ALL AREAS OF FILL SHALL BE INSTALLED IN LIFTS, COMPACTED, AND TESTED AS OUTLINED IN THE GRADINGSPECIFICATIONS.14. EXCAVATE THE PROPOSED DRAINAGE SWALE AND INSTALL THE ACCESS ROAD CULVERT. IMMEDIATELY STABILIZE THESWALE WITH EROSION CONTROL BLANKET AND PROVIDE CULVERT OUTLET PROTECTION.15. CONTRACTOR SHALL ENSURE THAT THERE IS PROPER COVER AND PROTECTION OVER ALL CULVERTS PER DETAIL SHEETC01-0816. FINALIZE THE INSTALLATION OF THE ACCESS DRIVES (INCLUDING STONE), COMPLETE GRADING, AND STABILIZE ALLDISTURBED AREAS BY SEEDING AND MULCHING.17. HAUL AWAY OR DISPOSE OF ANY EXCESS SOILS NOT NEEDED TO BALANCE SITE. IF ANY TOPSOIL IS TO REMAINSTOCKPILED, PROTECT WITH SILT FENCING AROUND PERIMETER.18. SOIL STABILIZATION MEASURES SHALL BE INITIATED AS SOON AS PRACTICABLE IN PORTIONS OF THE SITE WHERECONSTRUCTION ACTIVITIES HAVE TEMPORARILY OR PERMANENTLY CEASED, BUT IN NO CASE MORE THAN FOURTEEN (14)DAYS AFTER WORK HAS CEASED.19. TEMPORARY SEEDING SHALL BE PUT IN PLACE ON GRADED SLOPES AND DENUDED AREAS FOLLOWING INITIAL SOILDISTURBANCE.20. AFTER ALL CONSTRUCTION ACTIVITIES HAVE CEASED AND THE SITE IS STABILIZED, INSTALL PERMANENT VEGETATION ONTHE DISTURBED AREAS.21. ONCE CULVERTS ARE INSTALLED, RIP RAP APRONS ARE TO BE INSTALLED AT DOWNSTREAM OUTLET.22. SEDIMENT CONTROL LOGS TO BE INSTALLED AT DOWNSTREAM DITCHES AND SURROUNDING ALL WETLANDS23. ALL EROSION AND SEDIMENT CONTROL MEASURES WILL BE INSPECTED EVERY SEVEN (7) DAYS. NEEDED REPAIRS WILL BEMADE IMMEDIATELY.PHASE 324. THE SILT FENCE MUST BE MAINTAINED AS DESIGNED UNTIL ALL PERMANENT VEGETATION IS ESTABLISHED.25. THE SITE MUST ATTAIN FINAL STABILIZATION:25.1. ALL CONSTRUCTION ACTIVITIES THAT DISTURB SOIL ARE COMPLETE25.2. 100% PERENNIAL VEGETATION WITH 80% DENSITY25.3. ALL STORMWATER DISCHARGES FROM CONSTRUCTION ACTIVITIES AUTHORIZED BY THIS PERMIT ARE ELIMINATED25.4. ALL TEMPORARY SEDIMENT CONTROLS ARE REMOVED AND PROPERLY DISPOSED AND PERMANENTSTABILIZATION MEASURES HAVE BEEN EMPLOYED.26. A NOTICE OF TERMINATION (NOT) DOES NOT NEED TO BE SUBMITTED TO CDPHE, BUT FINAL STABILIZATION OF THE SITESTILL NEEDS TO BE ATTAINED FOR THIS TO OCCUR.GENERAL NOTES - COR400000 PERMIT1. OBTAIN ALL APPLICABLE PERMITS PRIOR TO CONSTRUCTION.2. ANY STOCKPILES SHALL BE SURROUNDED BY SILT FENCE ON ALL SIDES EXCEPT FOR THEINGRESS/EGRESS. (3 SIDES)3. CONTRACTOR IS RESPONSIBLE FOR REVIEWING GEOTECHNICAL REPORTS ACCOMPANYING ANYGRADING SPECIFICATIONS FOR PERTINENT SITE SOILS INFORMATION.4. ADDITIONAL PERTINENT EROSION CONTROL MEASURES TO BE DETAILED IN OVERALL SITEGRADING AND EROSION CONTROL PLAN.5. ALL SUBGRADE, FILL, AND STONE SHALL BE COMPACTED AS SPECIFIED IN THE GRADINGSPECIFICATIONS.6. FOLLOW PHASES 1, 2, AND 3 OF THE CONSTRUCTION SEQUENCE FOR GENERAL PROCESS ANDPROJECT PHASING.7. ALL DISTANCES SHOWN ARE NAD83 COLORADO STATE PLANE, SOUTH ZONE. ZONE GRIDDISTANCES IN U.S. FEET UNLESS OTHERWISE SPECIFIED.8. CLARIFICATIONS MAY BE ADDRESSED BY8.1. CONTACTING MR. ANDREW MERRITT., P.E.; Email: AMERITT@NEIENG.COM / PHONE: (303)339-67608.2. CONSULTING THE COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT (CDPHE)WEBSITE. PARCEL 25580559056 0 0 56 1 0 55605570558055905 5 9 05590 56 0 0 5 6 1 0 56205580559056005 6 1 0 5620561056205 6 3 05620563056 4 0 5650 561056105610 56205630564056 5 0 5660 56705660559055805 5 9 05610SFSFSFSFSCLSCLSCLSCLSCLSCLSCLSCLSCL SCLSCLWW W W W W W WW W W WWWWWWWWWWWWWWWWWWWW WWWWW GGGGGGGGGPARCEL 1PARCEL 3EAGLE SPRINGS ORGANIC, LLCAPN: 217918100691EAGLE SPRINGS ORGANIC, LLCAPN: 21791174007310EAGLE SPRINGS ORGANIC, LLCAPN: 217917300732EAGLE SPRINGS ORGANIC, LLCAPN: 217917300732B & B MAMM CREEK, LLCAPN: 217919100511BEDROCK RESOURCES, LLCAPN: 217918400720ORGANIC GROWERS, LLCAPN: 21791720068760' USA DOE ESMTOVERHEAD POWER LINES(HOLY CROSS)ESMTOVERHEAD POWER LINES(HOLY CROSS)PROCESS WATERLINE (2)GASLINE (1)PROCESS WATERLINE (2)GASLINE (1)PROCESS WATERLINE (2)GASLINE (1)EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. WELLPADEX. WELLPADPROCESS WATERLINE (2)GASLINE (1)EX. OUTBUILDINGEX.GREENHOUSESEX. OUTBUILDINGEX. OUTBUILDINGEX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. WELLPADEX. GRAVEL ACCESSROAD ℄PARCELBOUNDARY(TYP)EX. CULVERT ℄EX. LOW MAINTENANCE ROAD ℄EX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. CONCRETE PAD(USE UNKNOWN)EXISTINGSOLAR SITEEX. CULVERT ℄EX. EPHEMERAL DITCHOVERHEAD POWER LINES(HOLY CROSS)SFSFSFSFSFLODLODLODLODLODLODSFSFSFSFSFSFSF SFSFSFSFSFSFSFSFVTCVTCCWVTCTSSTSSSCLSCLSFSFSFSFSFSF SF SF SFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSF SFSFSFSFTSSSFOSF SF SFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFOSFODATEPROJECT TITLE:DESCRIPTIONAPV:PROJECT LOCATION:NO.KEY PLAN:PE STAMP:REVISIONS:SHEET NO:REV:SCALE AT 24" x 36":CHK:DWN:DES:DATE:PROJNUM:SHEET TITLE & DESCRIPTION:2180 South 1300 East, Suite 600Salt Lake City, UT 84106-2749(801) 679 - 3500ELECTRIC POWER ENGINEERING, INC.12600 W. COLFAX AVE, STE. C500LAKEWOOD, CO 80215(303) 431-7895 www.neieng.com0 75' 150' 225' 300'1" = 150'PHASE 1 (TEMPORARY)----FOR PERMITSUBMITTALPENDING GOVERNINGAUTHORITY APPROVALNGENERAL LEGENDEXISTING FEATURESPROPOSED FEATURESPROPOSED ACCESS ROADLoDPROPOSED DISTURBANCE LIMITSPROPOSED SECURITY FENCEPROPOSED CONSTRUCTION LAYDOWN AREAPROPOSED EQUIPMENT PADEXISTING PARCEL LINEEXISTING FENCEEXISTING EASEMENTEXISTING POWER POLEEXISTING ROAD CENTERLINEEXISTING OVERHEAD POWERPROPOSED CULVERTWEXISTING PROCESS WATERLINEGEXISTING GASLINEEXISTING MAJOR CONTOUREXISTING MINOR CONTOURTSSTEMPORARY SOIL STOCKPILE1. PERMANENT STABILIZATION TO BE ACHIEVED USING GRASSSEED COVERED WITH STRAW OR OTHER MULCHES ANDTACKIFIERS, ROLLED EROSION CONTROL PRODUCTS WITHGRASS SEED, OR BY HYDROSEEDING.2. PERMANENT SEEDING MIX SPECIFIED IN "EAGLE SPRINGSORGANIC-VEGETATION MANAGEMENT AND RECLAMATIONPLAN-FINAL_03-22-2023".3. SURVEY AND TOPOGRAPHY DATA TAKEN FROM "EAGLESPRINGS_REV2.DWG" BY ROADRUNNER SURVEY & MAPPING,INC.; DATED NOVEMBER 20, 2022.4. EPHEMERAL DITCHES SHOWN AS PROVIDED BY AES.NOTES5530PLOTTED: 3/29/2023 8:42 AMH:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\Solar\PV CIV\SWMP Exhibits\ECP-01.03 PHASE 1 (TEMPORARY).dwgXREFs: H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\AES Titleblock Outline.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\CIVIL.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\ESPR1 - EAGLE SPRINGS_REV2.dwg; H:\Project\3800\3803.001 Northumberland Solar - IEA\Drawings\_NEI\_References\PR-PLAN.dwg; .\PV-C.03.02 CIVIL SITE PLAN.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\CIVIL-CONSTRAINTS.dwgAES Titleblock 24X36 v210209 EAGLE SPRINGSORGANICSILT, CO4084.001JDJDRDBRDB3/22/23ECP-01.03 AA 3/22/23 ISSUED FOR REVIEW- - -- - -- - -- - -- - -- - -- - -PROPOSED SEDIMENT BERMSFPROPOSED SILT FENCESCLPROPOSED SEDIMENT CONTROL LOGEXISTING DITCHEROSION CONTROLVEHICLE TRACKING CONTROL CONSTRUCTION ENTRANCEBMP LEGENDSFSILT FENCELODLIMIT OF DISTURBANCETSTEMPORARY SEEDINGPROPOSED INTERCONNECTION POLESCWACONCRETE WASHOUT AREAVTCVEHICLE TRACKING CONTROLSFOSILT FENCE OUTLETSCLSEDIMENT CONTROL LOGTEMPORARY SEEDING PARCEL 25580559056 0 0 56 1 0 55605570558055905 5 9 05590 56 0 0 5 6 1 0 56205580559056005 6 1 0 5620561056205 6 3 05620563056 4 0 5650 561056105610 56205630564056 5 0 5660 56705660559055805 5 9 05610SFSFSFSFSCLSCLSCLSCLSCLSCLSCL SCLSCLWW W W W W W WW W W WWWWWWWWWWWWWWWWWWWW WWWWW GGGGGGGGGPARCEL 1PARCEL 3EAGLE SPRINGS ORGANIC, LLCAPN: 217918100691EAGLE SPRINGS ORGANIC, LLCAPN: 21791174007310EAGLE SPRINGS ORGANIC, LLCAPN: 217917300732EAGLE SPRINGS ORGANIC, LLCAPN: 217917300732B & B MAMM CREEK, LLCAPN: 217919100511BEDROCK RESOURCES, LLCAPN: 217918400720ORGANIC GROWERS, LLCAPN: 21791720068760' USA DOE ESMTOVERHEAD POWER LINES(HOLY CROSS)ESMTOVERHEAD POWER LINES(HOLY CROSS)PROCESS WATERLINE (2)GASLINE (1)PROCESS WATERLINE (2)GASLINE (1)PROCESS WATERLINE (2)GASLINE (1)EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. WELLPADEX. WELLPADPROCESS WATERLINE (2)GASLINE (1)EX. OUTBUILDINGEX.GREENHOUSESEX. OUTBUILDINGEX. OUTBUILDINGEX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. WELLPADEX. GRAVEL ACCESSROAD ℄PARCELBOUNDARY(TYP)EX. CULVERT ℄EX. LOW MAINTENANCE ROAD ℄EX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. CONCRETE PAD(USE UNKNOWN)EXISTINGSOLAR SITEEX. CULVERT ℄EX. EPHEMERAL DITCHOVERHEAD POWER LINES(HOLY CROSS)SFSFSFSFSFLODLODLODLODLODLODSFSFSFSFSFSFSF SFSFSFSFSFSFSFSFTSTSTSTSTSTSTSVTCVTCTSCWVTCTSSTSSSCLSCLSFSFSFSFSFSF SF SF SFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFOSF SF SFSFSFSFSFSFSFSFSFSFTSSSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFOSFODATEPROJECT TITLE:DESCRIPTIONAPV:PROJECT LOCATION:NO.KEY PLAN:PE STAMP:REVISIONS:SHEET NO:REV:SCALE AT 24" x 36":CHK:DWN:DES:DATE:PROJNUM:SHEET TITLE & DESCRIPTION:2180 South 1300 East, Suite 600Salt Lake City, UT 84106-2749(801) 679 - 3500ELECTRIC POWER ENGINEERING, INC.12600 W. COLFAX AVE, STE. C500LAKEWOOD, CO 80215(303) 431-7895 www.neieng.com0 75' 150' 225' 300'1" = 150'PHASE 2 (INTERIM)----GENERAL LEGENDEXISTING FEATURESPROPOSED FEATURESPROPOSED ACCESS ROADLoDPROPOSED DISTURBANCE LIMITSPROPOSED SECURITY FENCEPROPOSED CONSTRUCTION LAYDOWN AREAPROPOSED EQUIPMENT PADEXISTING PARCEL LINEEXISTING FENCEEXISTING EASEMENTEXISTING POWER POLEEXISTING ROAD CENTERLINEEXISTING OVERHEAD POWERPROPOSED CULVERTWEXISTING PROCESS WATERLINEGEXISTING GASLINEEXISTING MAJOR CONTOUREXISTING MINOR CONTOURTSSTEMPORARY SOIL STOCKPILE1. PERMANENT STABILIZATION TO BE ACHIEVED USING GRASSSEED COVERED WITH STRAW OR OTHER MULCHES ANDTACKIFIERS, ROLLED EROSION CONTROL PRODUCTS WITHGRASS SEED, OR BY HYDROSEEDING.2. PERMANENT SEEDING MIX SPECIFIED IN "EAGLE SPRINGSORGANIC-VEGETATION MANAGEMENT AND RECLAMATIONPLAN-FINAL_03-22-2023".3. SURVEY AND TOPOGRAPHY DATA TAKEN FROM "EAGLESPRINGS_REV2.DWG" BY ROADRUNNER SURVEY & MAPPING,INC.; DATED NOVEMBER 20, 2022.4. EPHEMERAL DITCHES SHOWN AS PROVIDED BY AES.NOTES5530PLOTTED: 3/29/2023 8:45 AMH:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\Solar\PV CIV\SWMP Exhibits\ECP-01.04 PHASE 2 (INTERIM).dwgXREFs: H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\AES Titleblock Outline.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\ESPR1 - ARRAYS - 45%.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\CIVIL.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\ESPR1 - EAGLE SPRINGS_REV2.dwg; H:\Project\3800\3803.001 Northumberland Solar - IEA\Drawings\_NEI\_References\PR-PLAN.dwg; .\PV-C.03.02 CIVIL SITE PLAN.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\CIVIL-CONSTRAINTS.dwgAES Titleblock 24X36 v210209 EAGLE SPRINGSORGANICSILT, CO4084.001JDJDRDBRDB3/22/23ECP-01.04 AA 3/22/23 ISSUED FOR REVIEW- - -- - -- - -- - -- - -- - -- - -SFPROPOSED SILT FENCESCLPROPOSED SEDIMENT CONTROL LOGEXISTING DITCHEROSION CONTROLTEMPORARY SEEDINGRIPRAPBMP LEGENDSFSILT FENCELODLIMIT OF DISTURBANCETSTEMPORARY SEEDINGPROPOSED INTERCONNECTION POLESCWACONCRETE WASHOUT AREAVTCVEHICLE TRACKING CONTROLSCLSEDIMENT CONTROL LOGFOR PERMITSUBMITTALPENDING GOVERNINGAUTHORITY APPROVALNSFOSILT FENCE OUTLET 5580559056 0 0 56 1 0 55605570558055905 5 9 05590 56 0 0 5 6 1 0 56205580559056005 6 1 0 5620561056205 6 3 05620563056 4 0 5650 561056105610 56205630564056 5 0 5660 56705660559055805 5 9 05610SCLSCLSCLSCLSCLSCLSCL SCLSCLWW W W W W W WW W W WWWWWWWWWWWWWWWWWWWW WWWWW GGGGGGGGGPARCEL 1PARCEL 2PARCEL 3EAGLE SPRINGS ORGANIC, LLCAPN: 217918100691EAGLE SPRINGS ORGANIC, LLCAPN: 21791174007310EAGLE SPRINGS ORGANIC, LLCAPN: 217917300732EAGLE SPRINGS ORGANIC, LLCAPN: 217917300732B & B MAMM CREEK, LLCAPN: 217919100511BEDROCK RESOURCES, LLCAPN: 217918400720ORGANIC GROWERS, LLCAPN: 21791720068760' USA DOE ESMTOVERHEAD POWER LINES(HOLY CROSS)ESMTOVERHEAD POWER LINES(HOLY CROSS)PROCESS WATERLINE (2)GASLINE (1)PROCESS WATERLINE (2)GASLINE (1)PROCESS WATERLINE (2)GASLINE (1)EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. WELLPADEX. WELLPADPROCESS WATERLINE (2)GASLINE (1)EX. OUTBUILDINGEX.GREENHOUSESEX. OUTBUILDINGEX. OUTBUILDINGEX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. GRAVEL ACCESSROAD ℄EX. WELLPADEX. GRAVEL ACCESSROAD ℄PARCELBOUNDARY(TYP)EX. CULVERT ℄EX. LOW MAINTENANCE ROAD ℄EX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. EPHEMERAL DITCHEX. CONCRETE PAD(USE UNKNOWN)EXISTINGSOLAR SITEEX. CULVERT ℄EX. EPHEMERAL DITCHOVERHEAD POWER LINES(HOLY CROSS)SFSFSFSFSFSFLODPSPSPSPSPSPSPSPSPSLODLODLODLODLODPSSCLSCLSFSFSFSFSFSF SF SF SFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSF SF SFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFDATEPROJECT TITLE:DESCRIPTIONAPV:PROJECT LOCATION:NO.KEY PLAN:PE STAMP:REVISIONS:SHEET NO:REV:SCALE AT 24" x 36":CHK:DWN:DES:DATE:PROJNUM:SHEET TITLE & DESCRIPTION:2180 South 1300 East, Suite 600Salt Lake City, UT 84106-2749(801) 679 - 3500ELECTRIC POWER ENGINEERING, INC.12600 W. COLFAX AVE, STE. C500LAKEWOOD, CO 80215(303) 431-7895 www.neieng.com0 75' 150' 225' 300'1" = 150'PHASE 3 (FINAL)----GENERAL LEGENDEXISTING FEATURESPROPOSED FEATURESPROPOSED ACCESS ROADLoDPROPOSED DISTURBANCE LIMITSPROPOSED SECURITY FENCEPROPOSED EQUIPMENT PADEXISTING PARCEL LINEEXISTING FENCEEXISTING EASEMENTEXISTING POWER POLEEXISTING ROAD CENTERLINEEXISTING OVERHEAD POWERPROPOSED CULVERTWEXISTING PROCESS WATERLINEGEXISTING GASLINEEXISTING MAJOR CONTOUREXISTING MINOR CONTOUR1. PERMANENT STABILIZATION TO BE ACHIEVED USING GRASSSEED COVERED WITH STRAW OR OTHER MULCHES ANDTACKIFIERS, ROLLED EROSION CONTROL PRODUCTS WITHGRASS SEED, OR BY HYDROSEEDING.2. PERMANENT SEEDING MIX SPECIFIED IN "EAGLE SPRINGSORGANIC-VEGETATION MANAGEMENT AND RECLAMATIONPLAN-FINAL_03-22-2023".3. SURVEY AND TOPOGRAPHY DATA TAKEN FROM "EAGLESPRINGS_REV2.DWG" BY ROADRUNNER SURVEY & MAPPING,INC.; DATED NOVEMBER 20, 2022.4. EPHEMERAL DITCHES SHOWN AS PROVIDED BY AES.NOTES5530PLOTTED: 3/29/2023 8:48 AMH:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\Solar\PV CIV\SWMP Exhibits\ECP-01.05 PHASE 3 (FINAL).dwgXREFs: H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\AES Titleblock Outline.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\ESPR1 - ARRAYS - 45%.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\CIVIL.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\ESPR1 - EAGLE SPRINGS_REV2.dwg; H:\Project\3800\3803.001 Northumberland Solar - IEA\Drawings\_NEI\_References\PR-PLAN.dwg; .\PV-C.03.02 CIVIL SITE PLAN.dwg; H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\CIVIL-CONSTRAINTS.dwgAES Titleblock 24X36 v210209 EAGLE SPRINGSORGANICSILT, CO4084.001JDJDRDBRDB3/22/23ECP-01.05 AA 3/22/23 ISSUED FOR REVIEW- - -- - -- - -- - -- - -- - -- - -SFPROPOSED SILT FENCESCLPROPOSED SEDIMENT CONTROL LOGEXISTING DITCHEROSION CONTROLPERMANENT SEEDINGRIPRAPBMP LEGENDSFSILT FENCELODLIMIT OF DISTURBANCEPSPERMANENT SEEDINGPROPOSED INTERCONNECTION POLESFOR PERMITSUBMITTALPENDING GOVERNINGAUTHORITY APPROVALN DATEPROJECT TITLE:DESCRIPTIONAPV:PROJECT LOCATION:NO.KEY PLAN:PE STAMP:REVISIONS:SHEET NO:REV:SCALE AT 24" x 36":CHK:DWN:DES:DATE:PROJNUM:SHEET TITLE & DESCRIPTION:2180 South 1300 East, Suite 600Salt Lake City, UT 84106-2749(801) 679 - 3500ELECTRIC POWER ENGINEERING, INC.12600 W. COLFAX AVE, STE. C500LAKEWOOD, CO 80215(303) 431-7895 www.neieng.comNTSEROSION CONTROLDETAILS----PLOTTED: 3/29/2023 8:49 AMH:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\Solar\PV CIV\SWMP Exhibits\ECP-01.06 EROSION CONTROL DETAILS.dwgXREFs: H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\AES Titleblock Outline.dwg AES Titleblock 24X36 v210209 EAGLE SPRINGSORGANICSILT, CO4084.001JDJDRDBRDB3/22/23ECP-01.06 AA 3/22/23 ISSUED FOR REVIEW- - -- - -- - -- - -- - -- - -- - -FOR PERMITSUBMITTALPENDING GOVERNINGAUTHORITY APPROVAL DATEPROJECT TITLE:DESCRIPTIONAPV:PROJECT LOCATION:NO.KEY PLAN:PE STAMP:REVISIONS:SHEET NO:REV:SCALE AT 24" x 36":CHK:DWN:DES:DATE:PROJNUM:SHEET TITLE & DESCRIPTION:2180 South 1300 East, Suite 600Salt Lake City, UT 84106-2749(801) 679 - 3500ELECTRIC POWER ENGINEERING, INC.12600 W. COLFAX AVE, STE. C500LAKEWOOD, CO 80215(303) 431-7895 www.neieng.comNTSEROSION CONTROLDETAILS----PLOTTED: 3/29/2023 8:49 AMH:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\Solar\PV CIV\SWMP Exhibits\ECP-01.06 EROSION CONTROL DETAILS.dwgXREFs: H:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\2_Sheetset References\AES Titleblock Outline.dwg AES Titleblock 24X36 v210209 EAGLE SPRINGSORGANICSILT, CO4084.001JDJDRDBRDB3/22/23ECP-01.07 AA 3/22/23 ISSUED FOR REVIEW- - -- - -- - -- - -- - -- - -- - -FOR PERMITSUBMITTALPENDING GOVERNINGAUTHORITY APPROVAL