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HomeMy WebLinkAbout3.01 Grading_Drainage Plan Article 4-203.E Grading and Drainage Plan Ursa Operating Company LLC Speakman A Injection Well OA Project No. 013-3151 CRUXX Civil Engineering & Development Consultants CRUx Consulting Group 110 E. 3rd Street Suite 204 │Rifle, Colorado 81650 970.319.9744 (o/c) February 18, 2014 Mr. Scott Aibner River Valley Survey email: saibner@comcast.net RE: Speakman A Pan – Drainage Review Letter Dear Scott: The CRUXX Consulting Group, Inc. has completed a drainage review for the Speakman A Pad proposed small injection well Garfield County Administrative Review land use permit. This review is being submitted to satisfy the Garfield County Regulatory Requirements outlined in section 4-203 (E) of the Garfield County Land Use and Development Code. The project is unique in that no proposed surface improvements are being completed for the small injection well application that will alter or change the existing gas pad site grading or drainage. However, because Garfield County did not formally review and approve the gas pad (constructed under the guidelines of the COGCC), the site is being evaluated for grading and drainage impacts the development of the gas pad pay have had at the time of construction, and any proposed improvements that may be necessary to be in compliance with the requirements of Garfield County. The purpose of this drainage letter is to review the “Historic”, as defined for purposes of this letter as pre-gas pad development, and the “Existing”, as defined as post gas pad development. Methodology The peak runoff flows for the analysis were determined using the Rational Method. The Urban Drainage Flood Control District (UDFCD) Rational Method spreadsheets were utilized to calculate design flows. Design criteria established by Garfield County require that the peak discharge rate does not exceed the Historic peak rate for the 2 year and 25 year storm events. The County also requires that storm water detention facilities (if required) must demonstrate that there is safe passage of the 100 year event without causing property damage. Based on the NOAA Atlas 2, Volume 3 precipitation maps that cover the project area the 1-Hour rainfall for the 2 year, 25 year and 100 year 24 hour precipitation events were estimated to be 0.56, 1.10 and 1.43 inches per hour respectively. CRUXX Civil Engineering & Development Consultants CRUx Consulting Group 110 E. 3rd Street Suite 204 │Rifle, Colorado 81650 970.319.9744 (o/c) The type of ground cover and soils affects the runoff volume from a site. The USDS NRCS Web Soil Survey was utilized to determine the soils data. The survey determined the primary majority soil type within the limits of the project is 56-Potts Loam with a hydrologic soil group rating of “C” indicative of slow rate of water infiltration. Runoff coefficient numbers were calculated in the Rational Method Spreadsheets and are determined based on the impervious area within each basin. The travel lengths and time of concentration were also calculated in the spreadsheets and based upon overland flow, shallow concentrated flow and channelized flow characteristics. Historic Conditions The existing topography of the “Historic” site, before the gas pad was installed, drained in general from south to the northeast corner joining flows within a large gulch. The site had several constraints, which limited the runoff potential. A steep ridgeline separated the site from the Private Road “Daybreak Drive” on the west and property to the north, and a large ravine was located adjacent to the eastern property boundary. Several vehicle trails and primitive roadways had been constructed that entered the property from the northeast, The reviewed historic property resulted in a tributary basin approximately 9.85 acres in size, with sage brush and sparse vegetation indicative of the western Garfield County region. Information on the historic property was gathered through the original survey data and COGCC submittal that contained photo documentation pre-disturbance. Historic storm water flows were calculated using a historic imperviousness of 2% and yielded a Q2/Q25 = 0.59/7.99 cfs at a design point at the northeast side of the property. Existing Conditions In 2010, development of the gas pad for extraction altered the site, however many of the historic constraints remained. The pad site remained bound on the west and north by the ridgeline separating it from the Private Road “Daybreak Drive”, and situated a flat rectangular pad between the ridgeline and the gulch to the east. In 2013 the pad was expanded southerly approximately 100-ft but did not change the pad characteristics or storm water flow patterns. The pad connected to Daybreak Drive to the south via a private access road that was installed with the pad. The main tributary basin was reduced to approximately 6.48 acres in size, and the existing storm water flows were determined to be Q2/Q25 = 0.52/5.21 cfs. An imperviousness of 5% was utilized in the calculations to accommodate barrels and pipe improvements located on the gas well site. APPENDIX A Hydrologic Data NRCS Soils Information Project Title: Catchment ID: I.Catchment Hydrologic Data Catchment ID =H1 Area =9.85Acres Percent Imperviousness =2.00% NRCS Soil Type =CA, B, C, or D II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3 Design Storm Return Period, Tr =2years(input return period for design storm) C1 =28.50(input the value of C1) C2=10.00(input the value of C2) C3=0.786(input the value of C3) P1=0.56inches(input one-hr precipitation--see Sheet "Design Info") III.Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C =0.06 Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 =0.16 Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS LandHeavyTillage/ShortNearlyGrassed TypeMeadowFieldPasture/BareSwales/ LawnsGroundWaterways Conveyance2.5571015 Calculations:ReachSlopeLength5-yr NRCSFlowFlow IDS L RunoffConvey-VelocityTime CoeffanceV Tf ft/ftftC-5 fpsminutes inputinputoutputinputoutputoutput Overland0.06003000.16N/A0.3116.22 10.1500789 8.003.104.24 2 8.00 3 8.00 4 5 1,089 Computed Tc=20.46 Regional Tc =16.05 User-Entered Tc =16.05 IV.Peak Runoff Prediction Rainfall Intensity at Computed Tc, I =1.09inch/hrPeak Flowrate, Qp =0.59cfs Rainfall Intensity at Regional Tc, I =1.23inch/hrPeak Flowrate, Qp =0.67cfs Rainfall Intensity at User-Defined Tc, I =1.23inch/hrPeak Flowrate, Qp =0.67cfs (Sheet Flow) 20 Shallow Paved Swales Sum CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Speak A Pad Drainage Historic -2 Year Paved Areas & Speakman Historic.xls, Tc and PeakQ2/19/2014, 1:21 PM Project Title: Catchment ID: I.Catchment Hydrologic Data Catchment ID =H1 Area =9.85Acres Percent Imperviousness =2.00% NRCS Soil Type =CA, B, C, or D II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3 Design Storm Return Period, Tr =25years(input return period for design storm) C1 =28.50(input the value of C1) C2=10.00(input the value of C2) C3=0.786(input the value of C3) P1=1.10inches(input one-hr precipitation--see Sheet "Design Info") III.Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C =0.38 Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 =0.16 Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS LandHeavyTillage/ShortNearlyGrassed TypeMeadowFieldPasture/BareSwales/ LawnsGroundWaterways Conveyance2.5571015 Calculations:ReachSlopeLength5-yr NRCSFlowFlow IDS L RunoffConvey-VelocityTime CoeffanceV Tf ft/ftftC-5 fpsminutes inputinputoutputinputoutputoutput Overland0.06003000.16N/A0.3116.22 10.1500789 8.003.104.24 2 8.00 3 8.00 4 5 1,089 Computed Tc=20.46 Regional Tc =16.05 User-Entered Tc =16.05 IV.Peak Runoff Prediction Rainfall Intensity at Computed Tc, I =2.14inch/hrPeak Flowrate, Qp =7.99cfs Rainfall Intensity at Regional Tc, I =2.42inch/hrPeak Flowrate, Qp =9.04cfs Rainfall Intensity at User-Defined Tc, I =2.42inch/hrPeak Flowrate, Qp =9.04cfs (Sheet Flow) 20 Shallow Paved Swales Sum CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Speak A Pad Drainage Historic -25 Year Paved Areas & Speakman Historic.xls, Tc and PeakQ2/19/2014, 1:20 PM Project Title: Catchment ID: I.Catchment Hydrologic Data Catchment ID =EX Area =6.48Acres Percent Imperviousness =5.00% NRCS Soil Type =CA, B, C, or D II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3 Design Storm Return Period, Tr =2years(input return period for design storm) C1 =28.50(input the value of C1) C2=10.00(input the value of C2) C3=0.786(input the value of C3) P1=0.56inches(input one-hr precipitation--see Sheet "Design Info") III.Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C =0.08 Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 =0.18 Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS LandHeavyTillage/ShortNearlyGrassed TypeMeadowFieldPasture/BareSwales/ LawnsGroundWaterways Conveyance2.5571015 Calculations:ReachSlopeLength5-yr NRCSFlowFlow IDS L RunoffConvey-VelocityTime CoeffanceV Tf ft/ftftC-5 fpsminutes inputinputoutputinputoutputoutput Overland0.05603000.18N/A0.3116.26 10.0850145 8.002.331.04 20.0640462 8.002.023.80 30.1500204 8.003.101.10 4 5 1,111 Computed Tc=22.20 Regional Tc =16.17 User-Entered Tc =16.17 IV.Peak Runoff Prediction Rainfall Intensity at Computed Tc, I =1.04inch/hrPeak Flowrate, Qp =0.52cfs Rainfall Intensity at Regional Tc, I =1.23inch/hrPeak Flowrate, Qp =0.61cfs Rainfall Intensity at User-Defined Tc, I =1.23inch/hrPeak Flowrate, Qp =0.61cfs CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Speakman A Pad Drainage Existing 2 year Paved Areas & (Sheet Flow) 20 Shallow Paved Swales Sum Speakman Existing.xls, Tc and PeakQ2/19/2014, 1:26 PM Project Title: Catchment ID: I.Catchment Hydrologic Data Catchment ID =EX Area =6.48Acres Percent Imperviousness =5.00% NRCS Soil Type =CA, B, C, or D II.Rainfall Information I (inch/hr) = C1 * P1 /(C2 + Td)^C3 Design Storm Return Period, Tr =25years(input return period for design storm) C1 =28.50(input the value of C1) C2=10.00(input the value of C2) C3=0.786(input the value of C3) P1=1.10inches(input one-hr precipitation--see Sheet "Design Info") III.Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C =0.39 Overide Runoff Coefficient, C =(enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 =0.18 Overide 5-yr. Runoff Coefficient, C =(enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS LandHeavyTillage/ShortNearlyGrassed TypeMeadowFieldPasture/BareSwales/ LawnsGroundWaterways Conveyance2.5571015 Calculations:ReachSlopeLength5-yr NRCSFlowFlow IDS L RunoffConvey-VelocityTime CoeffanceV Tf ft/ftftC-5 fpsminutes inputinputoutputinputoutputoutput Overland0.05603000.18N/A0.3116.26 10.0850145 8.002.331.04 20.0640462 8.002.023.80 30.1500204 8.003.101.10 4 5 1,111 Computed Tc=22.20 Regional Tc =16.17 User-Entered Tc =16.17 IV.Peak Runoff Prediction Rainfall Intensity at Computed Tc, I =2.05inch/hrPeak Flowrate, Qp =5.21cfs Rainfall Intensity at Regional Tc, I =2.41inch/hrPeak Flowrate, Qp =6.13cfs Rainfall Intensity at User-Defined Tc, I =2.41inch/hrPeak Flowrate, Qp =6.13cfs CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Speakman A Pad Drainage Existing 25 year Paved Areas & (Sheet Flow) 20 Shallow Paved Swales Sum Speakman Existing.xls, Tc and PeakQ2/19/2014, 1:27 PM United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Rifle Area, Colorado, Parts of Garfield and Mesa Counties Speakman A Pad Natural Resources Conservation Service February 19, 2014 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/portal/ nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (http:// offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means 2 for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 Soil Map..................................................................................................................5 Soil Map................................................................................................................6 Legend..................................................................................................................7 Map Unit Legend..................................................................................................8 Map Unit Descriptions..........................................................................................8 Rifle Area, Colorado, Parts of Garfield and Mesa Counties............................10 56—Potts loam, 6 to 12 percent slopes......................................................10 58—Potts-Ildefonso complex, 12 to 25 percent slopes...............................10 References............................................................................................................13 4 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 5 6 Custom Soil Resource Report Soil Map 4367460 4367500 4367540 4367580 4367620 4367660 4367700 4367500 4367540 4367580 4367620 4367660 4367700 752880752920752960753000753040753080753120753160753200753240 752880752920752960753000753040753080753120753160753200753240 39° 25' 18'' N 108° 3' 45'' W 39° 25' 18'' N 108° 3' 29'' W 39° 25' 10'' N 108° 3' 45'' W 39° 25' 10'' N 108° 3' 29'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 12N WGS84 050100200300 Feet 02550100150 Meters Map Scale: 1:1,730 if printed on A landscape (11" x 8.5") sheet. MAP LEGENDMAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 7, Dec 23, 2013 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 22, 2010—Sep 3, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 7 Map Unit Legend Rifle Area, Colorado, Parts of Garfield and Mesa Counties (CO683) Map Unit SymbolMap Unit NameAcres in AOIPercent of AOI 56Potts loam, 6 to 12 percent slopes 4.872.7% 58Potts-Ildefonso complex, 12 to 25 percent slopes 1.827.3% Totals for Area of Interest6.6100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If Custom Soil Resource Report 8 intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha- Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 9 Rifle Area, Colorado, Parts of Garfield and Mesa Counties 56—Potts loam, 6 to 12 percent slopes Map Unit Setting Elevation:5,000 to 7,000 feet Map Unit Composition Potts and similar soils:85 percent Description of Potts Setting Landform:Benches, mesas, valley sides Down-slope shape:Linear, convex Across-slope shape:Linear, convex Parent material:Alluvium derived from basalt and/or alluvium derived from sandstone and shale Properties and qualities Slope:6 to 12 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.60 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:15 percent Maximum salinity:Nonsaline (0.0 to 2.0 mmhos/cm) Available water capacity:High (about 10.3 inches) Interpretive groups Farmland classification:Farmland of statewide importance Land capability classification (irrigated):4e Land capability (nonirrigated):4e Hydrologic Soil Group:C Ecological site:Rolling Loam (R048AY298CO) Typical profile 0 to 4 inches:Loam 4 to 28 inches:Clay loam 28 to 60 inches:Loam 58—Potts-Ildefonso complex, 12 to 25 percent slopes Map Unit Setting Elevation:5,000 to 6,500 feet Map Unit Composition Potts and similar soils:60 percent Custom Soil Resource Report 10 Ildefonso and similar soils:30 percent Description of Potts Setting Landform:Mesas, alluvial fans, valley sides Down-slope shape:Convex, linear Across-slope shape:Convex, linear Parent material:Alluvium derived from basalt and/or alluvium derived from sandstone and shale Properties and qualities Slope:12 to 25 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.60 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:15 percent Maximum salinity:Nonsaline (0.0 to 2.0 mmhos/cm) Available water capacity:High (about 10.3 inches) Interpretive groups Farmland classification:Not prime farmland Land capability (nonirrigated):6e Hydrologic Soil Group:C Ecological site:Rolling Loam (R048AY298CO) Typical profile 0 to 4 inches:Loam 4 to 28 inches:Clay loam 28 to 60 inches:Loam Description of Ildefonso Setting Landform:Valley sides, mesas, alluvial fans Down-slope shape:Convex Across-slope shape:Convex Parent material:Alluvium derived from basalt and/or alluvium derived from sandstone and shale Properties and qualities Slope:12 to 25 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.60 to 6.00 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:35 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 4.0 mmhos/cm) Available water capacity:Low (about 5.1 inches) Custom Soil Resource Report 11 Interpretive groups Farmland classification:Not prime farmland Land capability (nonirrigated):6e Hydrologic Soil Group:A Typical profile 0 to 8 inches:Stony loam 8 to 60 inches:Very stony loam Custom Soil Resource Report 12 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http://www.nrcs.usda.gov/wps/ portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/ landuse/forestry/pub/ United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 13 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 14 THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION.