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HomeMy WebLinkAbout1.00 General Application Materials PO Box 248 Carbondale, CO 81623 (970) 947-9568 February 8, 2022 Community Development Department Garfield County 108 8th Street, Suite 401 Glenwood Springs, CO 81601 Re: Floodplain Development Permit Application for the Silt Boat Ramp – Parking and Circulation Improvement To whom it may concern, Introduction The purpose of this memorandum is to request a Floodplain Development Applications approval from the Garfield County for the Silt Boat Ramp – Parking and Circulation Improvement Project (Project). RiverRestoration has been hired to perform engineering design services for the Project by the Middle Colorado Watershed Council (MCWC). The applicant is the Town of Silt, who will be self-performing the construction of the project. Project Description The Project proposes improvements of the Town of Silt’s existing boat ramp parking area. The current site limits the available parking for vehicles with trailers and often results in congestion in the parking area and along County Road 311. The proposed design will expand the parking area and add parking stall delineators and signage to improvement traffic flow. The project will also add a pedestrian path between the parking area and the river to reduce conflicts between vehicles and pedestrians. Proposed improvements to enhance the area include:  Refurbishment/regrading of 0.73 acres of existing gravel parking area.  Additional 0.49 acres of new gravel parking area.  Additional 0.04 acres of new gravel boat staging area.  Additional 0.03 acres of new pedestrian pathway to connect parking area to river access points.  Add parking spot delineators to organize parking and travels area.  Add signage to parking and travel areas to improve parking efficiency and vehicle/pedestrian traffic flow.  Restoration of construction access to pre-project conditions Total permanent change to the floodplain is 1.29 acres. There is no proposed change to the areas below ordinary high water or within wetlands. Disturbance area of the project during construction is approximately 1.4 acres, including all staging, construction access, and stockpile areas. Section 3-301 Compliance A. Use Restrictions in Floodplain Overlay - The project is located outside of the floodway but within the 100-year floodplain. A detailed study of this reach has not been performed, so BFE’s and floodway boundaries are not available. See the attached floodplain map. Of the available categories, the project fits best in “Recreational and Open Space Structures and uses not requiring permanent or temporary PO Box 248 Carbondale, CO 81623 (970) 947-9568 structures designed for human habitation”. This category of work is permitted in the 100-year floodplains as long as there is compliance with all other applicable standards of the Code. B. General Standards - Proposed improvements include gravel pavement and signage that will be resistant to damage and flotation during a flood event. C. Specific Standards – N/A - a BFE has not been provided in the project location. (FEMA Zone A) D. Floodway – N/A – the Project is not located in a Floodway. (FEMA Zone A) E. Standards for Areas of Shallow Flooding – The project improvements are primarily a change in surface material from packed soil/vegetation to gravel. The project has a net fill of 98 CY, but this is primarily in an area lower than the existing travel lane immediately adjacent to it and will not increase flooding potential. See the attached Floodplain Compliance Memo, dated December 22, 2021, for more information. F. Properties Removed from the Floodplain by Fill – N/A – The Project does not remove the project from the floodplain. G. Alteration of a Water Course – N/A - No work is proposed within the wet channel of the Colorado River, and the water course will not be altered. H. Standards for Critical Facilities – N/A – The Project is not considered a critical facility. Section 4-109 Compliance (only applicable sub-sections listed) The project is in compliance with Section 3-301, Floodplain Overlay Regulations. A Floodplain Compliance Evaluation and Certification Letter is included in this submittal as part of a separate memo. (Floodplain Compliance, Silt Boat Ramp – Parking and Circulation Improvement Project, dated December 22, 2021). See additional explanation in the response to 3-301.C above. The project seeks to improve parking and traffic flow at an existing Town of Silt facility. No structures or fill that projects above the surround floodplain are being proposed. By its nature, it is required for the project to be at its proposed location. The project will not impact adjacent property owners. Based on this analysis, there would be no danger to life and property due to flooding or erosion damage; the would be no danger of materials being swept onto other lands, resulting in injury; the proposed project would be compatible with existing and anticipated development; there would be no impact to the property in times of flood for ordinary and emergency vehicles; there would be no impact to the costs of providing governmental services during and after flood conditions, including maintenance and repair of streets and bridges, and public utilities and facilities such as sewer, gas, electrical, and water systems; the would be no change in the heights, velocities, duration, rate of rise, and sediment transport of flood waters that would pose increased risk of damage or risk to public safety; there would be no impact of the necessity to PO Box 248 Carbondale, CO 81623 (970) 947-9568 the facility of waterfront location; there are no alternate locations not subject to flooding or erosion damage for the proposed project; and there is no impact to the comprehensive plan for the area. Section 4-203 Compliance (only applicable sub-sections listed) Based on review, construction drawings meet requirements of section 4-203. A. Professional Qualifications The project was designed under direction and guidance of a Professional Engineer in the state of Colorado, license #38823 (Romeo Baylosis) and #56481 (Quinn Donnelly). B. General Application Materials See attached documents for the general application materials submitted as part of this Floodplain Development Application. C. Vicinity Map See attached vicinity map showing the location of the project on the Colorado River south of Silt, CO and immediately east of County Road 311. D. Site Plan See attached plan set (Silt Boat Ramp – Parking and Circulation Improvements, Dated January 2022) for the Site Plan and the required elements. E. Grading and Drainage Plan See attached plan set (Silt Boat Ramp – Parking and Circulation Improvements, Dated January 2022) for the Grading and Drainage Plan and the required elements. Project specifications are available upon request. Construction Schedule: The Town of Silt is self-performing the work and will begin construction upon approval of this permit application from Garfield County. The work is expected to take between 30 and 60 days and the Town has a goal of completing the improvements prior to the boating season, which begins in early April. Permanent Stabilization: The proposed improvement areas will consist of compacted gravel paving. See the attached plans for mor information. Erosion and Sediment Control: Erosion and Sediment Control (ESC) BMPs will be implemented to minimize impacts to the Colorado River and its riparian area. These BMPs include erosion logs, silt fence, and check dams. See the ESC layout and details in the attached plan set for more information. Estimated Cost: The total estimate construction cost for the project, including soft costs and contingency is $201,133. Complete engineer’s cost opinion is available upon request. Stormwater Management Plan: PO Box 248 Carbondale, CO 81623 (970) 947-9568 The Town of Silt will apply for a Stormwater Construction Permit issued by CDPHE. The Town of Silt will submit for and receive a construction dewatering permit through CDPHE if required, but it is not anticipated that dewatering will be needed. Reclamation, Revegetation and Soil Plan: Seeding and mulching will be used on the limited disturbance areas that are not included in the expanded gravel parking and staging areas. See the grading plan in attached plan set for more information. Hydraulic Calculations: See response to 3-301.G for a discussion on the hydraulic calculations. Spill Prevention Control and Countermeasures: From the project specifications: a. A Spill Cleanup Plan is wholly the responsibility of the CONTRACTOR and shall be posted and available at all times on site for all work areas prior to any construction activities and shall include coordination with local emergency response agencies. CONTRACTOR shall submit Spill Cleanup Plan to ENGINEER for review 5 days prior to the start of construction. b. A release of any chemical, oil, petroleum product, sewage, etc., which may enter waters of the State of Colorado (which include surface water, ground water and dry gullies or storm sewers leading to surface water) shall be reported to the Colorado Department of Public Health and Environment immediately (25-8-601 CRS) and form http://www.cdphe.state.co.us/hm/spillselfreportform.pdf and/or Toll-Free 24-hour Environmental Emergency Spill Reporting Line 1-877-518-5608 may be used. Written notification to the Department shall follow within five (5) days (5 CCR 1002-61, Section 61.8(5)(d)). Releases of petroleum products and certain hazardous substances listed under the Federal Clean Water Act (40 CFR Part 116) must be reported to the National Response Center as well as to Colorado Department of Public Health and Environment as required under the Clean Water Act and the Oil Pollution Act. Furthermore, contact must be made immediately, reporting any spill incident, with CPW, the OWNER and ENGINEER. c. Any incident spills that do not threaten water resources shall be reported to: Colorado Emergency Planning Committee (CEPC)(members include Colorado Department of Health and Environment - Hazardous Waste Division, Colorado Department of Public Safety - Division of Homeland Security and Emergency Management, and Colorado Department of Public Safety - Colorado State Patrol), at Toll-Free 24-hour Colorado Environmental Release and Incident Reporting Line 1-877-518-5608, https://www.colorado.gov/pacific/cdphe/wq-environmental-spills . Furthermore, contact must be made immediately, reporting any spill incident, with the Town New Castle Public Works Department, the OWNER and ENGINEER. The CONTRACTOR shall submit within 14 calendar days of knowledge of the release a written description of: the release (including the type and estimate of the amount of material released), the date that such PO Box 248 Carbondale, CO 81623 (970) 947-9568 release occurred, the circumstances leading to the release, the measures taken and/or planned to be taken to clean up the release, and steps to be taken to minimize the chance of future occurrences to the Executive Secretary F. Landscape Plan See attached plan set (Silt Boat Ramp – Parking and Circulation Improvements, Dated January 2022) for the site stabilization plan. The Town will avoid disturbing vegetated areas that are not slated for gravel paving. G. Impact Analysis 1) Adjacent Land Use The project will have no impact on adjacent land use 2) Site Features The project will have a temporary impact during construction and will avoid permanent impacts. The flowing waters of the Colorado River will not be impacted by this project. 3) Soil Characteristics The project will have not impact on soil characteristics 4) Geology and Hazard The project will have no impact on geologic characteristics 5) Groundwater and Aquifer Recharge Areas The project will have no impact on groundwater and aquifer recharge areas 6) Flora and Fauna The project will convert 0.56 acres of vegetated area to gravel parking. Most of this area is poor quality with compacted soils and social trails, though several small trees will be removed. See photo below. The proposed design limits the removal of large, native trees to just along the connector road between the parking and staging areas. See the attached plans for more details on tree removal. All temporary impacts will be restored as part of the project. Area to be converted to gravel parking. Small trees in center of photo will be removed. PO Box 248 Carbondale, CO 81623 (970) 947-9568 7) Critical wildlife habitat The project will have no impact to designated environmental resources, including critical wildlife habitat. Wetlands were delineated as part of the project design and were avoided when laying out proposed improvements. 8) The project will have no impact on potential radiation hazard 9) Any and all vapor, dust, smoke, noise, glare, or vibration will be managed during construction and avoided and minimized to the greatest extent practicable H. Rezoning Justification Report This is not applicable to this project I. Statement of Appeal Not applicable J. Development Agreement Not applicable K. Improvements Agreement Not applicable L. Traffic Study Not Applicable M. Water Supply and Disturbance Plan Not Applicable N. Wastewater Management and System Plan Not Applicable O. Floodplain Analysis The attached floodplain analysis (Floodplain Compliance Memo, dated December 22, 2021) meets the provisions of Section 4-203 (O). See write up on individual applicable sections below. 1. See attached plan set for compliance with this section. Note the project area is in a FEMA Zone A of the Colorado River floodplain, so no detailed study and resulting BFE’s floodway boundaries, etc. are available. 2. N/A - No structures are proposed for this project. 3. N/A - No structures are proposed for this project. 4. N/A – The water course (i.e., Colorado River) will not be altered as part of this project. 5. A “No-rise” Evaluation and Certification Letter is included in this submittal as part of a separate memo. (Floodplain Compliance Memo, dated December 22, 2021) PO Box 248 Carbondale, CO 81623 (970) 947-9568 Section 7-203 Compliance A. All proposed improvements are outside of the Typical and Ordinary High Water Mark (TOHWM). Proposed improvements within the 35 foot setback from the TOHWM are limited to new signs and two small sections of added gravel totaling a Proposed tree removal is also outside of this zone. No structures are proposed outside of the limits of ordinary high water, within the setback area. There is no significant removal of vegetation proposed as part of the project. All wetlands and mature vegetation will be identified in the field and protected in place. B. N/A – there are no structures proposed for this project. C. N/A – there are no structures proposed for this project. D. The project team and the Town of Silt will comply with all applicable state and federal laws. A 404 permit with the USACE is not required for the project as work will not affect Waters of the US. See the attached correspondence with USACE staff. The Town will apply for needed construction related CDPHE permits prior to the start of construction. Section 11 - Signs All signs proposed for the project are intended to direct parking and traffic and do not include commercial messages or advertisements. Per Section 11-102, H the project’s signs are exempt from the need for a Garfield County Sign Permit. Please contact me at the email address or phone number below with any questions or concerns. Sincerely, Quinn Donnelly, P.E. Project Manager, RiverRestoration.org (970) 947-9568 quinn.donnelly@riverrestoration.org Attachments: (1) Signed application form (2) Proof of ownership (3) Authorization to represent (4) Statement of authority (5) List of property owners within 200 ft (6) List of owners of mineral rights (7) Pay Agreement Form (8) Vicinity map (9) Construction drawings - Silt Boat Ramp – Parking and Circulation Improvements, Dated January 2022 (10) Floodplain Compliance Memo, dated December 22, 2021 PO Box 248 Carbondale, CO 81623 (970) 947-9568 ATTACHMENT (1) Signed application form Community Development Department 108 8th Street, Suite 401 Glenwood Springs, CO 81601 (970)945-8212 www.garfield-county.com LAND USE CHANGE PERMIT APPLICATION FORM TYPE OF APPLICATION Administrative Review Development in 100-Year Floodplain Limited Impact Review Development in 100-Year Floodplain Variance Major Impact Review Code Text Amendment Amendments to an Approved LUCP LIR MIR SUP Rezoning Zone District PUD PUD Amendment Minor Temporary Housing Facility Administrative Interpretation Vacation of a County Road/Public ROW Appeal of Administrative Interpretation Location and Extent Review Areas and Activities of State Interest Comprehensive Plan Amendment Accommodation Pursuant to Fair Housing Act Pipeline Development Variance Time Extension (also check type of original application) INVOLVED PARTIES Owner/Applicant Name: ________________________________________________ Phone: (______)_________________ Mailing Address: ______________________________________________________________________ City: _______________________________________ State: _______ Zip Code: ____________________ E-mail:_______________________________________________________________________________ Representative (Authorization Required) Name: ________________________________________________ Phone: (______)_________________ Mailing Address: ______________________________________________________________________ City: _______________________________________ State: _______ Zip Code: ____________________ E-mail:_______________________________________________________________________________ PROJECT NAME AND LOCATION Project Name: _____________________________________________________________________________________ Assessor’s Parcel Number: ___ ___ ___ ___ - ___ ___ ___ - ___ ___ - ___ ___ ___ Physical/Street Address: ________________________________________________________________ Legal Description: ______________________________________________________________________ _____________________________________________________________________________________ Zone District: ___________________________________ Property Size (acres): __________________ PO Box 248 Carbondale, CO 81623 (970) 947-9568 ATTACHMENT (2) Proof of ownership PO Box 248 Carbondale, CO 81623 (970) 947-9568 ATTACHMENT (3) Authorization to represent PO Box 248 Carbondale, CO 81623 (970) 947-9568 ATTACHMENT (4) Statement of authority PO Box 248 Carbondale, CO 81623 (970) 947-9568 ATTACHMENT (5) List of property owners within 200 ft 1/26/22, 4:42 PM Garfield County Land Explorer https://maps.garfield-county.com/landexplorer/1/1 Garfield County Colorado Land Explorer Print Results Search Buffer Draw Layers Measure Locate Basemap Search: Parcel Physical Address Owner 217910140002 RIVER FRONTAGE RD SILT SILT, TOWN OF 217910400110 241 311 COUNTY RD SILT ASPHALT PAVING CO 217910400176 311 COUNTY RD SILT BONES, LONNIE 217910400470 320 311 COUNTY RD SILT SILT, TOWN OF 217910400516 361 311 COUNTY RD SILT RIVER NEST LLC 217911200007 54 311 COUNTY RD SILT SILT 70 LLC 217911300469 320 311 COUNTY RD SILT SILT, TOWN OF 217911400383 1412 311 COUNTY RD SILT FREI FAMILY LIMITED PARTNERSHIP ROW Not available null Copy Excel PDF Print + – 0 300 600ft PIN 217911300469  Report  Tax  Files  email Account R230879 Owner SILT, TOWN OF Physical Address 320 311 COUNTY RD SILT 81652 Mailing Address PO BOX 70 SILT, CO 81652 Land Acres 29.17000008 2020 Mill Levy 73.8920   Garfield County Land Explorer Parcel Physical Address Owner Account Num Mailing Address 217910140002 RIVER FRONTAGE RD SILT SILT, TOWN OF R043694 PO BOX 70 SILT, CO 81652 217910400110 241 311 COUNTY RD SILT ASPHALT PAVING CO R023306 14802 W 44TH AVENUE GOLDEN, CO 80403-1824 217910400176 311 COUNTY RD SILT BONES, LONNIE R023063 PO BOX 442 SILT, CO 81652 217910400470 320 311 COUNTY RD SILT SILT, TOWN OF R230880 PO BOX 70 SILT, CO 81652 217910400516 361 311 COUNTY RD SILT RIVER NEST LLC R230948 361 COUNTY ROAD 311 SILT, CO 81652 217911200007 54 311 COUNTY RD SILT SILT 70 LLC R044679 10106 W SAN JUNA WAY SUITE 205 LITTLETON, CO 80127 217911300469 320 311 COUNTY RD SILT SILT, TOWN OF R230879 PO BOX 70 SILT, CO 81652 217911400383 1412 311 COUNTY RD SILT FREI FAMILY LIMITED PARTNERSHIP R023436 287 MID VALLEY DRIVE NEW CASTLE, CO 81647 ROW Not available null Garfield County Land Explorer about:blank 1 of 1 1/26/2022, 4:22 PM PO Box 248 Carbondale, CO 81623 (970) 947-9568 ATTACHMENT (6) List of owners of mineral rights PO Box 248 Carbondale, CO 81623 (970) 947-9568 ATTACHMENT (7) Agreement to pay form PO Box 248 Carbondale, CO 81623 (970) 947-9568 ATTACHMENT (8) Vicinity map 16th StreetColorado River Colorado River Project Limits Garfield Co Parcel Owners and Numbers I70 Silt Boat Ramp – Parking and Circulation Improvements Garfield County Floodplain Development Permit Vicinity Map PO Box 248 Carbondale, CO 81623 (970) 947-9568 ATTACHMENT (9) Construction drawings ft Corporation © 2022 Maxar ©CNES (2022) Distribution Airbus DS © 2022 TomTom Cover SheetC001CONSTRUCTION DOCUMENTSSILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROAD, SILT, COLORADO 81652GARFIELD COUNTYTitle:Drawing No:1-31-2022SILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROADSILT, COLORADO 81652, GARFIELD COUNTYSHEET INDEXPROJECT CONTACTSVICINITY MAPC:\Users\romea\OneDrive\Civil-Proj21\2103 SBR\Dwg\CD\SBR C-Cover.dwg, 1/31/2022 8:19:14 PM, AutoCAD PDF (General Documentation).pc3,1:1 Notes andAbbreviationsC002CONSTRUCTION DOCUMENTSSILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROAD, SILT, COLORADO 81652GARFIELD COUNTYTitle:Drawing No:1-31-2022C:\Users\romea\OneDrive\Civil-Proj21\2103 SBR\Dwg\CD\SBR C-LegendNoteAbbreviation.dwg, 1/31/2022 8:19:24 PM, AutoCAD PDF (General Documentation).pc3,1:1 LEGENDEXISTINGPROPOSEDExistingConditionsC003CONSTRUCTION DOCUMENTSSILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROAD, SILT, COLORADO 81652GARFIELD COUNTYTitle:Drawing No:1-31-2022C:\Users\romea\OneDrive\Civil-Proj21\2103 SBR\Dwg\CD\SBR C-ExistingCondition.dwg, 1/31/2022 8:19:39 PM, AutoCAD PDF (General Documentation).pc3,1:1 EXPANDED PARKING18 SPACESRECONFIGURE PARKING16 SPACES + 1 ADATRAILER PARKING8 SPACESTRAILER PARKING11 SPACESLEGENDEXISTINGPROPOSEDSite PlanC101CONSTRUCTION DOCUMENTSSILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROAD, SILT, COLORADO 81652GARFIELD COUNTYTitle:Drawing No:1-31-2022C:\Users\romea\OneDrive\Civil-Proj21\2103 SBR\Dwg\CD\SBR C-Site.dwg, 1/31/2022 8:19:55 PM, AutoCAD PDF (General Documentation).pc3,1:1 EXPANDED PARKING18 SPACESRECONFIGURE PARKING16 SPACES + 1 ADATRAILER PARKING8 SPACESTRAILER PARKING11 SPACESLEGENDEXISTINGPROPOSEDOverall AerialCO-83CF GarCoC102CONSTRUCTION DOCUMENTSSILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROAD, SILT, COLORADO 81652GARFIELD COUNTYTitle:Drawing No:1-31-2022C:\Users\romea\OneDrive\Civil-Proj21\2103 SBR\Dwg\Silt Boat Ramp_CO-83CF_GarCo.dwg, 1/31/2022 8:20:21 PM, AutoCAD PDF (General Documentation).pc3,1:1 LEGENDEXISTINGPROPOSEDSigning andMarking PlanC103CONSTRUCTION DOCUMENTSSILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROAD, SILT, COLORADO 81652GARFIELD COUNTYTitle:Drawing No:1-31-2022C:\Users\romea\OneDrive\Civil-Proj21\2103 SBR\Dwg\CD\SBR C-SigningMarking.dwg, 1/31/2022 8:20:45 PM, AutoCAD PDF (General Documentation).pc3,1:1 EXPANDED PARKING18 SPACESRECONFIGURE PARKING16 SPACES + 1 ADATRAILER PARKING8 SPACESTRAILER PARKING11 SPACESLEGENDEXISTINGPROPOSEDTurningMovementsVehicle TrackingC201CONSTRUCTION DOCUMENTSSILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROAD, SILT, COLORADO 81652GARFIELD COUNTYTitle:Drawing No:1-31-2022C:\Users\romea\OneDrive\Civil-Proj21\2103 SBR\Dwg\CD\SBR C-RoadVehicleTracking.dwg, 1/31/2022 8:21:05 PM, AutoCAD PDF (General Documentation).pc3,1:1 EROSION CONTROL LEGENDLEGENDEXISTINGPROPOSEDGrading andDrainage PlanC301CONSTRUCTION DOCUMENTSSILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROAD, SILT, COLORADO 81652GARFIELD COUNTYTitle:Drawing No:1-31-2022C:\Users\romea\OneDrive\Civil-Proj21\2103 SBR\Dwg\CD\SBR C-GradingDrainage.dwg, 1/31/2022 8:21:42 PM, AutoCAD PDF (General Documentation).pc3,1:1 DRAINAGE SWALE - GRASS LINEDNOT TO SCALEACCESS AND PARKING PAVEMENT SECTIONNOT TO SCALEBOULDER RETAINING WALLNOT TO SCALEWOODEN PARKING DELINEATORNOT TO SCALESite DetailsC401CONSTRUCTION DOCUMENTSSILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROAD, SILT, COLORADO 81652GARFIELD COUNTYTitle:Drawing No:1-31-2022C:\Users\romea\OneDrive\Civil-Proj21\2103 SBR\Dwg\CD\SBR C-DetailSite.dwg, 1/31/2022 8:43:29 PM, DWG To PDF.pc3,1:1 Erosion ControlDetailsC402CONSTRUCTION DOCUMENTSSILT BOAT RAMPPARKING AND CIRCULATION IMPROVEMENTS320 311 COUNTY ROAD, SILT, COLORADO 81652GARFIELD COUNTYTitle:Drawing No:1-31-2022C:\Users\romea\OneDrive\Civil-Proj21\2103 SBR\Dwg\CD\SBR C-DetailErosionControl.dwg, 1/31/2022 8:28:20 PM, AutoCAD PDF (General Documentation).pc3,1:1 PO Box 248 Carbondale, CO 81623 (970) 947-9568 ATTACHMENT (10) Floodplain Compliance Memo PO Box 248 Carbondale, CO 81623 (970) 947-9568 1 December 22, 2021 Glenn Hartmann, Senior Planner Garfield County Community Development 108 8th Street, Suite #401 Glenwood Springs, CO 81601 RE: Floodplain Compliance, Silt Boat Ramp – Parking and Circulation Improvement Project Dear Glenn, The purpose of this memorandum is to document the floodplain impacts of the proposed Silt Boat Ramp – Parking and Circulation Improvement Project. This letter describes how the proposed modifications comply with the Garfield County Land Use and Development Code and Federal floodplain development guidelines. The Town of Silt (Town) proposes to make improvements to the existing parking lot and circulation pattern for the Town’s boat ramp on the Colorado River. The project is located on an island in the main stem of the Colorado River, immediately upstream (east) of County Road 311. See Figure 1 for a vicinity map of the project location. Figure 1 - Vicinity Map of Proposed Project PO Box 248 Carbondale, CO 81623 (970) 947-9568 Existing Conditions The site has served as the Town’s public access to the Colorado River for at least several decades. The existing configuration consists of a driveway off CR 311, a parking area, a staging area, a drive connecting the two, and the boat ramp itself. The Town’s boat ramp sees heavy use, particularly with commercial fishing guides who fish this reach of the Colorado with clients. The parking lot is also used to access an off-leash dog park located on the east end of the island. The heavy use results in a shortage of parking spaces during certain days and times, leading to vehicles and trailers parked on CR 311. The current parking lot also lacks space delineators, which results in inefficient use of the existing space, creating traffic flow issues and further compounding the lack of sufficient parking spaces. Figure 2 shows an aerial image of the existing parking lot and boat ramp, facing north, with CR 311 of the left (west) side of the image. Figure 3 shows the staging area and boat ramp. Figure 2 - Existing parking area with Colorado River in background, flowing to the left. The project site is four vertical feet below the road surface of CR 311. It is also located between the two bridges CR 311 uses to cross over the two branches of the Colorado River. The combination of these two factors leaves the majority of the project site in an ineffective flow area of the Colorado River flood flow as it contracts through the two bridge openings during high water events. The project site is in a section of the Colorado River that is not a detailed study area for FEMA, meaning that a hydraulic model, such as HEC-RAS was not used for delineating the 100-year floodplain boundary. As such, the 100-year Floodplain is categorized as PO Box 248 Carbondale, CO 81623 (970) 947-9568 Zone A and a Base Flood Elevation has not been established. A copy of the current FIRM is included as an Attachment A. Figure 3 - Existing Staging Area and Boat Ramp with Colorado River in foreground, flowing to the right. Proposed Conditions The proposed project will improve the parking and circulation of the site with additional parking spaces to the south, parking delineators, changes to the staging area, and a widened connecting lane. See the 90% design plans included as Attachment B. The are no proposed changes to the boat ramp itself or work below ordinary high water. The project was designed to limit changes in grade and to minimize import and haul off. The existing parking lot will be refurbished and regraded to improve drainage. The new parking area with remove scrub brush and vegetation and replace it with aggregate base. These proposed changes will add additional parking for vehicles with and without trailers and improve traffic circulation. The project includes 351 CY of cut and 449 CY of fill with a net fill of 98 CY. The majority of this net fill is in the connector lane widening area, in an area lower than the existing connector lane. Comparing the existing to propose grade over the entire site, the mean difference is +0.04’. Attachment C includes cross sections through several areas of the proposed improvements to compare existing and proposed grade. PO Box 248 Carbondale, CO 81623 (970) 947-9568 The project team delineated wetlands on the site and avoided impacts to aquatic resources during the design process. Because there is no work being performed in wetlands or below ordinary high water a Clean Water Act, Section 404 permit is not required. See Attachment D for email correspondence with the US Army of Engineers. RiverRestoration asserts that a detailed floodplain analysis is not necessary for this project. There is no established Base Flood Elevation, and the project is located in a likely ineffective flow area due to the raised road immediately downstream and the bridge openings on each side. Proposed changes to existing grade are minimal and the floodplain roughness will be reduced with the additional gravel parking area, larger staging area, and widened connecting lane, likely increasing conveyance capacity in areas where effective conveyance is occurring. In conclusion, the proposed project will not create a rise in water surface elevations associated with the 100-year floodplain of the Colorado River or change the extents of the 100-year floodplain boundary in the project reach. If you have any additional questions or comments in regard to this Floodplain Compliance Memo, please feel free to contact us at your convenience. Respectfully, Quinn Donnelly, P.E. River Engineer quinn.donnelly@riverrestoration.org (970) 947-9568 Attachments: (A) Current FEMA Floodplain Map of the Colorado River through the Project Reach (B) 90% Design Drawings for the proposed project improvements (C) Cross Sections comparing existing to proposed grade. (D) Email correspondence with USACE on CWA Section 404 permit. PO Box 248 Carbondale, CO 81623 (970) 947-9568 Attachment A: Current FEMA Floodplain Map of the Colorado River through the Project Reach National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V, A99 With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mileZone X Future Conditions 1% Annual Chance Flood HazardZone X Area with Reduced Flood Risk due to Levee. See Notes.Zone X Area with Flood Risk due to LeveeZone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood HazardZone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 11/9/2021 at 7:53 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. 1:6,000 107°39'3"W 39°32'41"N 107°38'25"W 39°32'13"N Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020 PO Box 248 Carbondale, CO 81623 (970) 947-9568 Attachment B: 90% Design Drawings for the proposed project improvements. PO Box 248 Carbondale, CO 81623 (970) 947-9568 Attachment C: Cross Sections comparing existing to proposed grade. Silt BR - XS 1 - Parking PROFILE HORIZ. SCALE: 1" = 30' VERT. SCALE: 1" = 10' 5420 5430 5440 5450 5420 5430 5440 5450 0+00 0+50 1+00 1+50 2+00 2+35 Silt BR - XS 2 - Parking PROFILE HORIZ. SCALE: 1" = 30' VERT. SCALE: 1" = 10' 5420 5430 5440 5450 5420 5430 5440 5450 0+00 0+50 1+00 1+50 2+00 2+50 2+78 Silt BR - XS 3 - Parking PROFILE HORIZ. SCALE: 1" = 30' VERT. SCALE: 1" = 10' 5420 5430 5440 5450 5420 5430 5440 5450 0+00 0+50 1+00 1+50 2+00 2+44 Silt BR - XS 4 - Parking PROFILE HORIZ. SCALE: 1" = 30' VERT. SCALE: 1" = 10' 5420 5430 5440 5450 5420 5430 5440 5450 0+00 0+50 1+00 1+50 2+00 2+50 3+00 3+50 4+00 4+20 Silt BR - XS 5 - Connecting Lane PROFILE HORIZ. SCALE: 1" = 30' VERT. SCALE: 1" = 10' 5420 5430 5440 5450 5420 5430 5440 5450 0+00 0+50 1+00 1+50 1+71 Silt BR - XS 6 - Staging Area PROFILE HORIZ. SCALE: 1" = 30' VERT. SCALE: 1" = 10' 5420 5430 5440 5450 5420 5430 5440 5450 0+00 0+50 1+00 1+50 2+00 PO Box 248 Carbondale, CO 81623 (970) 947-9568 Attachment D: Email correspondence with USACE on CWA Section 404 permit. 1 Quinn Donnelly From:Morse, W Travis CIV USARMY CESPA (USA) <w.travis.morse@usace.army.mil> Sent:Friday, November 19, 2021 10:17 AM To:Quinn Donnelly Subject:RE: Silt Boat Ramp - Parking lot improvements SPA-2021-00378 Hi Quinn, Thank you for talking with me this morning about the subject project. As discussed, there is no need to coordinate this activity with the Corps if impacts to aquatic resources are not proposed. Best reagards, Travis Morse Senior Project Manager Northwestern Colorado Branch U.S. Army Corps of Engineers ពភមយរលវឝឞសហឡ 400 Rood Avenue, Room 224 Grand Junction, Colorado 81501 ፥፦፧፨፩ (970) 243-1199 ext. 1014 Please provide us with your feedback by filling out a customer survey at https://regulatory.ops.usace.army.mil/customer-service-survey/ From: Quinn Donnelly <quinn.donnelly@riverrestoration.org> Sent: Tuesday, November 9, 2021 5:38 PM To: Morse, W Travis CIV USARMY CESPA (USA) <w.travis.morse@usace.army.mil> Subject: ハ[WARNING: UNSCANNABLE EXTRACTION FAILED][WARNING: UNSCANNABLE EXTRACTION FAILED][WARNING: UNSCANNABLE EXTRACTION FAILED][Non-DoD Source] Silt Boat Ramp - Parking lot improvements Good evening Travis, Here’s a follow up to the voice mail I left. The Town of Silt is doing some in-house maintenance work to the parking lot for their boat ramp on the Colorado River. See attached google earth pin for location. The work includes expansion of the parking lot to the south and widening the access road between the ramp and the parking lot. Plus rearranging some existing boulders to provide pedestrian access to the river. The boat ramp the Town installed a couple of years ago will remain unchanged. See the attached 60% grading plan for content. We delineated wetlands and OHW (shown in plan as well) and designed the improvements to avoid impacts. I wanted to chat with you about what if anything is needed in regards to 404 compliance. Take a look and please give me a call when you have a few minutes to discuss. Cell phone is best. 503.413.0863. Thanks in advance for the help. V/R, Quinn -- Quinn Donnelly, PE