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HomeMy WebLinkAboutPOUDRE GARAGE - BDR160007 - SUBMITTAL DOCUMENTS - ROUND 2 - DRAINAGE REPORTMay 25, 2016 FINAL DRAINAGE REPORT FOR POUDRE GARAGE Fort Collins, Colorado Prepared for: Poudre Garage, LLC 148 Remington Street Fort Collins, Colorado 80524 Prepared by: 200 South College Avenue, Suite 10 Fort Collins, Colorado 80524 Phone: 970.221.4158 Fax: 970.221.4159 www.northernengineering.com Project Number: 998-002  This Drainage Report is consciously provided as a PDF. Please consider the environment before printing this document in its entirety. When a hard copy is absolutely necessary, we recommend double-sided printing. May 25, 2016 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, Colorado 80521 RE: Preliminary Drainage Report for POUDRE GARAGE Dear Staff: Northern Engineering is pleased to submit this Final Drainage Report for your review. This report accompanies the Project Development Plan submittal for the proposed Poudre Garage. This report has been prepared in accordance to Fort Collins Stormwater Criteria Manual (FCSCM), and serves to document the stormwater impacts associated with the proposed project. We understand that review by the City is to assure general compliance with standardized criteria contained in the FCSCM. If you should have any questions as you review this report, please feel free to contact us. Sincerely, NORTHERN ENGINEERING SERVICES, INC. Frederick S. Wegert, PE Project Engineer Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report TABLE OF CONTENTS I. GENERAL LOCATION AND DESCRIPTION ................................................................... 1 A. Location ............................................................................................................................................. 1 B. Description of Property ..................................................................................................................... 2 C. Floodplain.......................................................................................................................................... 3 II. DRAINAGE BASINS AND SUB-BASINS ....................................................................... 4 A. Major Basin Description .................................................................................................................... 4 B. Sub-Basin Description ....................................................................................................................... 4 III. DRAINAGE DESIGN CRITERIA ................................................................................... 5 A. Regulations........................................................................................................................................ 5 B. Four Step Process .............................................................................................................................. 5 C. Development Criteria Reference and Constraints ............................................................................ 6 D. Hydrological Criteria ......................................................................................................................... 6 E. Hydraulic Criteria .............................................................................................................................. 6 F. Modifications of Criteria ................................................................................................................... 6 IV. DRAINAGE FACILITY DESIGN .................................................................................... 6 A. General Concept ............................................................................................................................... 6 B. Specific Details .................................................................................................................................. 7 V. CONCLUSIONS ........................................................................................................ 8 A. Compliance with Standards .............................................................................................................. 8 B. Drainage Concept .............................................................................................................................. 8 APPENDICES: APPENDIX A.1 – Hydrologic Computations APPENDIX A.2 – NRCS Soils Report APPENDIX B.1 – LID Design Computations APPENDIX C.1 – Inlet Computations APPENDIX C.2 – Storm Line Computations Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report LIST OF FIGURES: Figure 1 - Vicinity Map ........................................................................................................ 1 Figure 2 – Aerial Photograph ................................................................................................ 2 Figure 3 – Proposed Site Plan ............................................................................................... 3 Figure 4 – Area Floodplain Mapping ...................................................................................... 4 MAP POCKET: Proposed Drainage Plan Proposed Drainage Plan with Disturbed Areas Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report 1 I. GENERAL LOCATION AND DESCRIPTION A. Location Figure 1 - Vicinity Map 1. The project site is located in the southwest quarter of Section 12, Township 7 North, Range 69 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. 2. The project site is located at 148 Remington Street at northwest corner of the intersection of Remington Street and Oak Street. 3. The project site lies within the Old Town Basin. The site drains to the storm sewer system in Oak Street, which is conveyed east to the Udall Water Quality Treatment Area, and ultimately discharging into the Cache La Poudre River. The proposed impervious area for the site is 3,294 square feet, and detention is not required since the proposed impervious area is less than the required 5,000 square feet. However, the site still must provide current City Low Impact Design (LID) requirements. Water quality treatment methods are described in further detail below. 4. As this is an infill site, the area surrounding the site is fully developed. 5. No offsite flows enter the site from the north, south, east or west. Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report 2 B. Description of Property 1. The development area is roughly 0.16 net acres (6,995 square feet). Figure 2 – Aerial Photograph 2. The subject property is currently composed of existing buildings and a hard-packed dirt parking lot. Existing ground slopes are mild (i.e., 1 - 4±%) through the interior of the property. General topography slopes from north to south. 3. According to the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Soil Survey website: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx, the site consists of Satanta loam (Hydrologic Soil Group B). The NRCS Soils Report is provided in Appendix A.2. 4. The proposed project site plan is composed of expanding the existing building to include a mixed use of commercial, residential, and covered parking for the residential units. Associated site work, water, and sewer lines will be constructed with the development. Current City Low Impact Design (LID) requirements will be implemented with the project, and will consist of several LID features which are discussed in Section IV, below. Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report 3 Figure 3 – Proposed Site Plan 5. There are no known irrigation laterals crossing the site. 6. The proposed land use is mixed use. 7. Total site disturbance is 8,500 square feet and does not require an Erosion Control Plan and Report per the FCSCM. However, it’s strongly encouraged the developer implements Best Management Practices during construction to reduce sediment into the City’s storm sewer system. At a minimum, the site must be swept and maintained to prevent dirt, saw cuttings, concrete wash, trash and debris, landscape materials and other pollutants from entering the storm sewer at all times. C. Floodplain 1. The project site is not encroached by any City or FEMA designated 100-year floodplain. Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report 4 Figure 4 – Area Floodplain Mapping II. DRAINAGE BASINS AND SUB-BASINS A. Major Basin Description 1. The project site lies within the Old Town Basin. Generally, detention requirements for this basin are to detain the difference between the 100-year developed inflow rate and the historic 2-year release rate. The City of Fort Collins allows up to 5,000 square feet of new impervious without requiring detention. New impervious area for the site is 3,294 square feet, and therefore, detention is not required. 2. The site drains into the Oak Street storm sewer system and conveyed to the Udall Water Quality Treatment Area. However, the site must comply with current City Low Impact Design (LID) requirements. Water quality treatment methods are described in further detail below. B. Sub-Basin Description 1. The subject property historically drains overland from north to south. Runoff from the majority of the site has historically been collected in existing inlets located within Remington Street and Oak Street. 2. A more detailed description of the project drainage patterns is provided below. Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report 5 III. DRAINAGE DESIGN CRITERIA A. Regulations There are no optional provisions outside of the FCSCM proposed with the proposed project. B. Four Step Process The overall stormwater management strategy employed with the proposed project utilizes the “Four Step Process” to minimize adverse impacts of urbanization on receiving waters. The following is a description of how the proposed development has incorporated each step. Step 1 – Employ Runoff Reduction Practices Several techniques have been utilized with the proposed development to facilitate the reduction of runoff peaks, volumes, and pollutant loads as the site is developed from the current use by implementing multiple Low Impact Development (LID) strategies including: Conserving existing amenities in the site including the existing vegetated areas. Providing vegetated open areas throughout the site to reduce the overall impervious area and to minimize directly connected impervious areas (MDCIA). Routing flows, to the extent feasible, through vegetated areas to increase time of concentration, promote infiltration and provide initial water quality. Step 2 – Implement BMPs That Provide a Water Quality Capture Volume (WQCV) with Slow Release The efforts taken in Step 1 will facilitate the reduction of runoff; however, urban development of this intensity will still generate stormwater runoff that will require additional BMPs and water quality. The stormwater runoff from the site will be intercepted and treated using rain gardens. Step 3 – Stabilize Drainageways There are no major drainageways within the subject property. While this step may not seem applicable to proposed development, the project indirectly helps achieve stabilized drainageways nonetheless. By providing water quality treatment, where none previously existed, sediment with erosion potential is removed from downstream drainageway systems. Furthermore, this project will pay one-time stormwater development fees, as well as ongoing monthly stormwater utility fees, both of which help achieve City-wide drainageway stability. Step 4 – Implement Site Specific and Other Source Control BMPs. The proposed project will improve upon site specific source controls compared to historic conditions: The proposed development will provide LID features which enhance water quality; thus, eliminating sources of potential pollution previously left exposed to weathering and runoff processes. Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report 6 C. Development Criteria Reference and Constraints The subject property is surrounded by currently developed properties. Thus, several constraints have been identified during the course of this analysis that will impact the proposed drainage system including: Existing elevations along the property lines will generally be maintained. As previously mentioned, overall drainage patterns of the existing site will be maintained. Elevations of existing downstream facilities that the subject property will release to will be maintained. D. Hydrological Criteria 1. The City of Fort Collins Rainfall Intensity-Duration Curves, as depicted in Figure RA- 16 of the FCSCM, serve as the source for all hydrologic computations associated with the proposed development. Tabulated data contained in Table RA-7 has been utilized for Rational Method runoff calculations. 2. The Rational Method has been employed to compute stormwater runoff utilizing coefficients contained in Tables RO-11 and RO-12 of the FCSCM. 3. Two separate design storms have been utilized to address distinct drainage scenarios. A third design storm has also been computed for comparison purposes. The first event analyzed is the “Minor,” or “Initial” Storm, which has a 2-year recurrence interval. The second event considered is the “Major Storm,” which has a 100-year recurrence interval. The third storm computed, for comparison purposes only, is the 10-year event. 4. No other assumptions or calculation methods have been used with this development that are not referenced by current City of Fort Collins criteria. E. Hydraulic Criteria 1. As previously noted, the subject property maintains historic drainage patterns. 2. All drainage facilities proposed with the project are designed in accordance with criteria outlined in the FCSCM and/or the Urban Drainage and Flood Control District (UDFCD) Urban Storm Drainage Criteria Manual. 3. As stated above, the subject property is not located in a City or FEMA designated floodplain. The proposed project does not propose to modify any natural drainageways. F. Modifications of Criteria 1. The proposed development is not requesting any modifications to criteria at this time. IV. DRAINAGE FACILITY DESIGN A. General Concept 1. The main objectives of the project drainage design are to maintain existing drainage patterns, and to ensure no adverse impacts to any adjacent properties. 2. Onsite LID features will be provided and will enhance water quality. These measures are discussed further below. Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report 7 3. Drainage patterns for proposed drainage basins as shown in the Drainage Exhibit are described below. Basin A Basin A will generally follow historic drainage patterns. Basin A will drain via overland flow, roof drains, and proposed storm sewer into the existing storm drain system within Oak Street. A proposed rain garden located within Basin A will discharge into the proposed building’s storm drain system. Basin OSA Basin OSA will follow historic drainage patterns via overland flow into the existing storm drain system within Oak Street. Basins B & OSB Minimal development will occur with Basins B and OSB. Basins B and OSB will generally drain via overland flow into the existing storm drain system within Remington Street. The emergency overflow for the rain garden will occur through Basins B & OSB. A full-size copy of the Drainage Exhibit can be found in the Map Pocket at the end of this report. Runoff computations for these basins based on the Rational Method is provided in Appendix A.1. B. Specific Details 1. Low Impact Development (LID) measures will consist of a rain garden in the northeast corner of the site. The rain garden was designed with a drain system that will outfall to the existing Oak Street storm drain. The rain garden was designed to treat 75% of the new impervious area for the site. Details of this design are provided within the Final plan set. The design spreadsheet “Design Procedure Form: Rain Garden (RG)” by the Urban Drainage and Flood Contol District (UDFCD) was utilized to compute the required LID treatment areas, and the design sheet is provided in Appendix B.1. This sheet shows the rain gardens are sized to treat 2,471 ft2, which meets the requirement shown in Table 1. Please also see additional information provided in the LID Requirement Table below (Table 1). The rain garden was designed with three overflow inlets. Each overflow inlet was sized to handle 50% of the 100-Year Storm Event with 50% of the grate opening clogged by debris (see Appendix C.1). Only two inlets are required to safely pass the 100-Year Storm Event; however, the third inlet provides an additional factor of safety for the 100-Year Storm Event in the constrained space in the northeast corner of the site. Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report 8 2. The following table summarizes proposed LID features and overall percentage of the basin being treated by the proposed LID features 75% On-Site Treatment by LID Requirements New Impervious Area 3,294 ft2 0.076 Ac. Traditional Pavement Area 59 ft2 0.001 Ac. Other Impervious Surfaces (Roofs, Concrete Walks, etc.) 3,235 ft2 0.075 Ac. Required Minimum Impervious Area to be Treated 2,471 ft2 0.057 Ac. Required Minimum Volume to be Treated 101 ft3 3.74 yd3 Design Volume of Rain Garden 113 ft3 4.18 yd3 Contributing Area to Rain Garden 2,471 ft2 0.057 Ac. Percent of Treatment of New Impervious Area (by area) 75% Table 1 – LID Treatment Requirements 3. Standard Operating Procedures (SOP) Manual shall be provided to the City of Fort Collins and included in the site Development Agreement. A final copy of the approved SOP manual shall be provided to City and must be maintained on-site by the entity responsible for the facility maintenance. Annual reports must also be prepared and submitted to the City discussing the results of the maintenance program (i.e. inspection dates, inspection frequency, volume loss due to sedimentation, corrective actions taken, etc.). 4. Proper maintenance of the drainage facilities designed with the proposed development is a critical component of their ongoing performance and effectiveness. V. CONCLUSIONS A. Compliance with Standards 1. The drainage design proposed with the proposed project complies with the City of Fort Collins’ Stormwater Criteria Manual. 2. The drainage design proposed with this project complies with requirements for the Old Town Basin. 3. The drainage plan and stormwater management measures proposed with the proposed development are compliant with all applicable State and Federal regulations governing stormwater discharge. B. Drainage Concept 1. The drainage design proposed with this project will effectively limit any potential damage associated with its stormwater runoff by compliance with requirements set forth in current City master plans. 2. The drainage concept for the proposed development is consistent with requirements for the Old Town Basin and the Downtown River District Final Design Report. Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Drainage Report 9 References 1. Fort Collins Stormwater Criteria Manual, City of Fort Collins, Colorado, as adopted by Ordinance No. 174, 2011, and referenced in Section 26-500 (c) of the City of Fort Collins Municipal Code. 2. Larimer County Urban Area Street Standards, Adopted January 2, 2001, Repealed and Reenacted, Effective October 1, 2002, Repealed and Reenacted, Effective April 1, 2007. 3. Soils Resource Report for Larimer County Area, Colorado, Natural Resources Conservation Service, United States Department of Agriculture. 4. Old Town Master Drainage Plan, Baseline Hydraulics, Volume II, Anderson Consulting, July 15, 2003. 5. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control District, Wright-McLaughlin Engineers, Denver, Colorado, Revised August 2013. Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Erosion Control Report APPENDIX A.1 HYDROLOGIC COMPUTATIONS Percent Impervious Developed 50% 10% Date: 95% Basin ID Basin Area (sq. ft.) Basin Area (ac) Gravel Area (ac.) Area of Lawns (ac.) Area of Impervious (ac.) Composite Percent Impervious 2-year Runoff Coefficient 2 5-year Runoff Coefficient 2 10-year Runoff Coefficient 2 100-year Runoff Coefficient 2 A 6,995 0.16 0.09 0.00 0.07 70.95% 0.45 0.49 0.53 0.62 OS-A 5,491 0.13 0.00 0.00 0.12 94.21% 0.77 0.79 0.81 0.87 OS-B 8,929 0.20 0.00 0.00 0.20 93.76% 0.76 0.78 0.80 0.85 Notes: 2) Runoff Coefficients are taken from the Urban Drainage and Flood Control District, Chapter 5, Table RO-5. Calculations By: F. Wegert EXISTING % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS Project: Poudre Garage Gravel Lawns Impervious Area 1) Percent impervious are taken from Fort Collins Amendments to the Urban Drainage and Flood Control District, Table RO-11, pg. 41. CHARACTER OF SURFACE 1 : May 25, 2016 5/23/2016 9:42 AM D:\Projects\998-002\Drainage\Hydrology\998-002_Pre-Developed_UDFCD_RM.xlsx\Basin Runoff Coefficient Overland Flow, Time of Concentration: Project: Calculations By: Date: Gutter/Swale Flow, Time of Concentration: T t = L / 60V T c = T i + T t (Equation RO-2) Velocity (Gutter Flow), V = 20·S ½ Velocity (Swale Flow), V = 15·S ½ Is Length >500' ? C 5 Length, L (ft) Slope, S (%) T i Length, L (ft) Slope, S (%) Velocity, V (ft/s) T t (min) Length, L (ft) Slope, S (%) Velocity, V (ft/s) T t (min) Urban Tc Check T c (min) Rational Method Equation: Project: Poudre Garage Calculations By: F. Wegert Date: May 25, 2016 Rainfall Intensity: A A 0.16 10.9 0.45 0.53 0.62 2.17 3.71 7.57 0.16 0.32 0.75 OS-A OS-A 0.13 10.6 0.77 0.81 0.87 2.17 3.71 7.57 0.21 0.38 0.83 OS-B OS-B 0.20 11.0 0.76 0.80 0.85 2.13 3.63 7.42 0.33 0.59 1.30 Notes EXISTING RUNOFF COMPUTATIONS FOR INDIVIDUAL BASINS Rainfall Intensity taken from the Larimer County Stormwater Design Standards, Adopted June 20, 2005, Figure RA-3. Design Point Basin(s) Area, A (acres) T c (min) C 2 C 10 C 100 Intensity, i 2 (in/hr) Intensity, i 10 (in/hr) Intensity, i 100 (in/hr) Flow, Q 2 (cfs) Flow, Q 10 (cfs) Flow, Q 100 (cfs) Q  C f  C  i  A  5/23/2016 9:43 AM D:\Projects\998-002\Drainage\Hydrology\998-002_Pre-Developed_UDFCD_RM.xlsx\Runoff Percent Impervious Developed 50% 10% Date: 95% Basin ID Basin Area (sq. ft.) Basin Area (ac) Gravel Area (ac.) Area of Lawns (ac.) Area of Impervious (ac.) Composite Percent Impervious 2-year Runoff Coefficient 2 5-year Runoff Coefficient 2 10-year Runoff Coefficient 2 100-year Runoff Coefficient 2 A 6,618 0.15 0.00 0.01 0.14 91.11% 0.73 0.75 0.77 0.82 B 377 0.01 0.00 0.00 0.01 95.00% 0.79 0.81 0.83 0.88 OS-A 5,491 0.13 0.00 0.01 0.12 88.31% 0.68 0.70 0.73 0.79 OS-B 8,929 0.20 0.00 0.00 0.20 93.76% 0.76 0.78 0.80 0.85 Notes: 2) Runoff Coefficients are taken from the Urban Drainage and Flood Control District, Chapter 5, Table RO-5. Calculations By: F. Wegert DEVELOPED BASIN % IMPERVIOUSNESS AND RUNOFF COEFFICIENT CALCULATIONS Project: Poudre Garage Gravel Lawns Impervious Area 1) Percent impervious are taken from Fort Collins Amendments to the Urban Drainage and Flood Control District, Table RO-11, pg. 41. CHARACTER OF SURFACE 1 : May 25, 2016 5/23/2016 9:39 AM D:\Projects\998-002\Drainage\Hydrology\998-002_Post-Developed_UDFCD_RM.xlsx\Basin Runoff Coefficient Overland Flow, Time of Concentration: Project: Calculations By: Date: Gutter/Swale Flow, Time of Concentration: T t = L / 60V T c = T i + T t (Equation RO-2) Velocity (Gutter Flow), V = 20·S ½ Velocity (Swale Flow), V = 15·S ½ Is Length >500' ? C 5 Length, L (ft) Slope, S (%) T i Length, L (ft) Slope, S (%) Velocity, V (ft/s) T t (min) Length, L (ft) Slope, S (%) Velocity, V (ft/s) T t (min) Urban Tc Check T c (min) Rational Method Equation: Project: Poudre Garage Calculations By: F. Wegert Date: May 25, 2016 Rainfall Intensity: A A 0.15 10.8 0.73 0.77 0.82 2.17 3.71 7.57 0.24 0.43 0.95 B B 0.01 5.0 0.79 0.83 0.88 2.85 4.87 9.95 0.02 0.03 0.08 OS-A OS-A 0.13 10.6 0.68 0.73 0.79 2.17 3.71 7.57 0.19 0.34 0.75 OS-B OS-B 0.20 11.0 0.76 0.80 0.85 2.13 3.63 7.42 0.33 0.59 1.30 Notes DEVELOPED RUNOFF COMPUTATIONS FOR INDIVIDUAL BASINS Rainfall Intensity taken from the Larimer County Stormwater Design Standards, Adopted June 20, 2005, Figure RA-3. Design Point Basin(s) Area, A (acres) T c (min) C 2 C 10 C 100 Intensity, i 2 (in/hr) Intensity, i 10 (in/hr) Intensity, i 100 (in/hr) Flow, Q 2 (cfs) Flow, Q 10 (cfs) Flow, Q 100 (cfs) Q  C f  C  i  A  5/23/2016 9:40 AM D:\Projects\998-002\Drainage\Hydrology\998-002_Post-Developed_UDFCD_RM.xlsx\Runoff Project Number: Project: Project Location: Calculations By: Date: Percent Impervious ● roof & concrete 3,257 ft 2 95% 3,094 ft 2 ● gravel 1 3,738 ft 2 50% 1,869 ft 2 4,963 ft 2 ● new roof & concrete 1 3,294 ft 2 95% 3,129 ft 2 3,129 ft 2 Note: 1) Gravel parking lot to be replaced with proposed building, concrete, and rain garden. Total New Impervious Area Existing Proposed Impervious Area for the Site 998-002 Poudre Garage Fort Collins, Colorado F. Wegert 5/25/2016 Area Weighted Area Total Existing Impervious Area 5/23/2016 9:44 AM D:\Projects\998-002\Drainage\Hydrology\998-002_Pre-Developed_UDFCD_RM.xlsx\New Impv Area Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Erosion Control Report APPENDIX A.2 NATURAL RESOURCES CONSERVATION SERVICE SOILS REPORT 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 Larimer County Natural Area, Colorado Resources Conservation Service January 28, 2016 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 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................7 Soil Map................................................................................................................8 Legend..................................................................................................................9 Map Unit Legend................................................................................................10 Map Unit Descriptions........................................................................................10 Larimer County Area, Colorado......................................................................12 35—Fort Collins loam, 0 to 3 percent slopes..............................................12 94—Satanta loam, 0 to 1 percent slopes....................................................13 Soil Information for All Uses...............................................................................15 Soil Properties and Qualities..............................................................................15 Soil Qualities and Features.............................................................................15 Hydrologic Soil Group.................................................................................15 References............................................................................................................20 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil scientists classified and named the soils in the survey area, they compared the 5 individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil- landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 6 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. 7 8 Custom Soil Resource Report Soil Map 4492730 4492740 4492750 4492760 4492770 4492780 4492790 4492800 4492810 4492820 4492830 4492840 4492850 4492730 4492740 4492750 4492760 4492770 4492780 4492790 4492800 4492810 4492820 4492830 4492840 4492850 493600 493610 493620 493630 493640 493650 493660 493670 493680 493600 493610 493620 493630 493640 493650 493660 493670 493680 40° 35' 11'' N 105° 4' 32'' W 40° 35' 11'' N 105° 4' 28'' W 40° 35' 7'' N 105° 4' 32'' W 40° 35' 7'' N 105° 4' 28'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 25 50 100 150 Feet 0 5 10 20 30 Meters Map Scale: 1:616 if printed on A portrait (8.5" x 11") sheet. MAP LEGEND MAP 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 Map Unit Legend Larimer County Area, Colorado (CO644) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 35 Fort Collins loam, 0 to 3 percent slopes 0.0 0.1% 94 Satanta loam, 0 to 1 percent slopes 1.7 99.9% Totals for Area of Interest 1.8 100.0% 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 10 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 11 Larimer County Area, Colorado 35—Fort Collins loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2tlnc Elevation: 4,020 to 6,730 feet Mean annual precipitation: 14 to 16 inches Mean annual air temperature: 46 to 48 degrees F Frost-free period: 143 to 154 days Farmland classification: Prime farmland if irrigated Map Unit Composition Fort collins and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Fort Collins Setting Landform: Interfluves Down-slope shape: Linear Across-slope shape: Linear Parent material: Pleistocene or older alluvium derived from igneous, metamorphic and sedimentary rock and/or eolian deposits Typical profile Ap - 0 to 4 inches: loam Bt1 - 4 to 9 inches: clay loam Bt2 - 9 to 16 inches: clay loam Bk1 - 16 to 29 inches: loam Bk2 - 29 to 80 inches: loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.20 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 12 percent Salinity, maximum in profile: Nonsaline (0.1 to 1.0 mmhos/cm) Sodium adsorption ratio, maximum in profile: 0.5 Available water storage in profile: High (about 9.1 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 4c Hydrologic Soil Group: C Ecological site: Loamy Plains (R067BY002CO) Custom Soil Resource Report 12 Minor Components Nunn Percent of map unit: 10 percent Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: Loamy Plains (R067BY002CO) Vona Percent of map unit: 5 percent Landform: Interfluves Landform position (two-dimensional): Backslope, footslope Landform position (three-dimensional): Side slope, base slope Down-slope shape: Linear Across-slope shape: Linear Ecological site: Sandy Plains (R067BY024CO) 94—Satanta loam, 0 to 1 percent slopes Map Unit Setting National map unit symbol: jpyc Elevation: 4,800 to 5,600 feet Mean annual precipitation: 13 to 15 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 135 to 150 days Farmland classification: Prime farmland if irrigated Map Unit Composition Satanta and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Satanta Setting Landform: Terraces Landform position (three-dimensional): Side slope, tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Mixed alluvium and/or eolian deposits Typical profile H1 - 0 to 12 inches: loam H2 - 12 to 18 inches: loam, clay loam, sandy clay loam H2 - 12 to 18 inches: loam, clay loam, fine sandy loam H2 - 12 to 18 inches: H3 - 18 to 60 inches: H3 - 18 to 60 inches: Custom Soil Resource Report 13 H3 - 18 to 60 inches: Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Available water storage in profile: Very high (about 26.4 inches) Interpretive groups Land capability classification (irrigated): 1 Land capability classification (nonirrigated): 3c Hydrologic Soil Group: B Minor Components Stoneham Percent of map unit: 6 percent Fort collins Percent of map unit: 6 percent Nunn Percent of map unit: 3 percent Custom Soil Resource Report 14 Soil Information for All Uses Soil Properties and Qualities The Soil Properties and Qualities section includes various soil properties and qualities displayed as thematic maps with a summary table for the soil map units in the selected area of interest. A single value or rating for each map unit is generated by aggregating the interpretive ratings of individual map unit components. This aggregation process is defined for each property or quality. Soil Qualities and Features Soil qualities are behavior and performance attributes that are not directly measured, but are inferred from observations of dynamic conditions and from soil properties. Example soil qualities include natural drainage, and frost action. Soil features are attributes that are not directly part of the soil. Example soil features include slope and depth to restrictive layer. These features can greatly impact the use and management of the soil. Hydrologic Soil Group Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long- duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. 15 Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Custom Soil Resource Report 16 17 Custom Soil Resource Report Map—Hydrologic Soil Group 4492730 4492740 4492750 4492760 4492770 4492780 4492790 4492800 4492810 4492820 4492830 4492840 4492850 4492730 4492740 4492750 4492760 4492770 4492780 4492790 4492800 4492810 4492820 4492830 4492840 4492850 493600 493610 493620 493630 493640 493650 493660 493670 493680 493600 493610 493620 493630 493640 493650 493660 493670 493680 40° 35' 11'' N 105° 4' 32'' W 40° 35' 11'' N 105° 4' 28'' W 40° 35' 7'' N 105° 4' 32'' W 40° 35' 7'' N 105° 4' 28'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 25 50 100 150 Feet 0 5 10 20 30 Meters Map Scale: 1:616 if printed on A portrait (8.5" x 11") sheet. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available 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: Larimer County Area, Colorado Table—Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado (CO644) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 35 Fort Collins loam, 0 to 3 percent slopes C 0.0 0.1% 94 Satanta loam, 0 to 1 percent slopes B 1.7 99.9% Totals for Area of Interest 1.8 100.0% Rating Options—Hydrologic Soil Group Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Custom Soil Resource Report 19 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/detail/soils/ home/?cid=nrcs142p2_053374 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 20 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 21 Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Erosion Control Report APPENDIX B.1 WATER WAWALID DESIGN COMPUTATIONS Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia = 100.0 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100) i = 1.000 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.40 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 2,471 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV = 82 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER = 0.0 cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER = cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum) DWQCV = 4.0 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 0.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin = 55 sq ft D) Actual Flat Surface Area AActual = 303 sq ft E) Area at Design Depth (Top Surface Area) ATop = 303 sq ft F) Rain Garden Total Volume VT= 101 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided? B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y = 1.7 ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 = 82 cu ft iii) Orifice Diameter, 3/8" Minimum DO = 0.22 in MINIMUM DIAMETER = 3/8" Design Procedure Form: Rain Garden (RG) Frederick Wegert Northern Engineering May 25, 2016 998-002 Rain Garden Onsite Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO UD-BMP_v3.02_Rngdn 75% Treatment.xls, RG 5/23/2016, 9:46 AM Sheet 2 of 2 Designer: Company: Date: Project: Location: 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is an impermeable liner provided due to proximity of structures or groundwater contamination? 6. Inlet / Outlet Control A) Inlet Control 7. Vegetation 8. Irrigation A) Will the rain garden be irrigated? Notes: Design Procedure Form: Rain Garden (RG) Frederick Wegert Northern Engineering May 25, 2016 998-002 Rain Garden Onsite Choose One Choose One Choose One Sheet Flow- No Energy Dissipation Required Concentrated Flow- Energy Dissipation Provided Plantings Seed (Plan for frequent weed control) Sand Grown or Other High Infiltration Sod Choose One YES NO YES NO UD-BMP_v3.02_Rngdn 75% Treatment.xls, RG 5/23/2016, 9:46 AM S C S H Y D D W D C S G EX. ELEC VAULT RD RD UD UD UD UD UD C T REMMINGTON STREET (100' ROW) 20' WIDE ALLEY EXISTING 1-STORY BRICK BUILDING EXISTING 1-STORY BRICK BUILDING EXISTING 2-STORY BRICK BUILDING OAK STREET (100' ROW) (M) N00°18'49"E 99.99' (R) NORTH 100' (M) S00°20'34"W 99.97' (R) SOUTH 100' (M) N89°42'10"W 69.94' (R) WEST 70' (M) S89°41'11"E 69.99' (R) EAST 70' EXISTING DOOR THRESHOLD ELEV. = 4982.52 EXISTING DOOR THRESHOLD ELEV. = 4982.44 EXISTING DOOR THRESHOLD ELEV. = 4983.99 EXISTING DOOR THRESHOLD ELEV. = 4984.04 EXISTING DOOR THRESHOLD ELEV. = 4982.56 EXISTING DOOR THRESHOLD ELEV. = 4982.46 EXISTING DOOR THRESHOLD ELEV. = 4982.42 EXISTING TREE WELL (TYP.) PRESERVE & PROTECT EXISTING TREE Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Erosion Control Report APPENDIX C.1 WATER WAWAINLET COMPUTATIONS Area Inlet Performance Curve: Rain Garden Inlet (North) Governing Equations: At low flow depths, the inlet will act like a weir governed by the following equation: * where P = 3.1416*Dia.of grate * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A) The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown. However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation will cross at a certain flow depth. The two curves can be found below: If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters: Type of Grate: Nyloplast 8" Dome Diameter of Grate (ft): 0.666666667 Open Area of Grate (ft2): 0.21 Rim Elevation (ft): 4987.750 Reduction Factor: 50% Depth vs. Flow: Depth Above Inlet (ft) Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs) 0.00 4987.75 0.00 0.00 0.00 0.20 4987.95 0.28 0.25 0.25 0.40 4988.15 0.79 0.36 0.36 0.60 4988.35 1.46 0.44 0.44 0.80 4988.55 2.25 0.50 0.50 1.00 4988.75 3.14 0.56 0.56 1.20 4988.95 4.13 0.62 0.62 1.40 4989.15 5.20 0.67 0.67 1.60 4989.35 6.36 0.71 0.71 1.80 4989.55 7.59 0.76 0.76 2.00 4989.75 8.89 0.80 0.80 Design Flow = 0.22 cfs Q  3 . 0 P H 1 . 5 Q  0 . 67 A ( 2 gH ) 0 . 5 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Discharge (cfs) Stage (ft) Stage - Discharge Curves Weir Flow Area Inlet Performance Curve: Rain Garden Inlet (Middle) Governing Equations: At low flow depths, the inlet will act like a weir governed by the following equation: * where P = 3.1416*Dia.of grate * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A) The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown. However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation will cross at a certain flow depth. The two curves can be found below: If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters: Type of Grate: Nyloplast 8" Dome Diameter of Grate (ft): 0.666666667 Open Area of Grate (ft2): 0.21 Rim Elevation (ft): 4981.750 Reduction Factor: 50% Depth vs. Flow: Depth Above Inlet (ft) Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs) 0.00 4981.75 0.00 0.00 0.00 0.20 4981.95 0.28 0.25 0.25 0.40 4982.15 0.79 0.36 0.36 0.60 4982.35 1.46 0.44 0.44 0.80 4982.55 2.25 0.50 0.50 1.00 4982.75 3.14 0.56 0.56 1.20 4982.95 4.13 0.62 0.62 1.40 4983.15 5.20 0.67 0.67 1.60 4983.35 6.36 0.71 0.71 1.80 4983.55 7.59 0.76 0.76 2.00 4983.75 8.89 0.80 0.80 Design Flow = 0.22 cfs Q  3 . 0 P H 1 . 5 Q  0 . 67 A ( 2 gH ) 0 . 5 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Discharge (cfs) Stage (ft) Stage - Discharge Curves Weir Flow Area Inlet Performance Curve: Rain Garden Inlet (South) Governing Equations: At low flow depths, the inlet will act like a weir governed by the following equation: * where P = 3.1416*Dia.of grate * where H corresponds to the depth of water above the flowline At higher flow depths, the inlet will act like an orifice governed by the following equation: * where A equals the open area of the inlet grate * where H corresponds to the depth of water above the centroid of the cross-sectional area (A) The exact depth at which the inlet ceases to act like a weir, and begins to act like an orifice is unknown. However, what is known, is that the stage-discharge curves of the weir equation and the orifice equation will cross at a certain flow depth. The two curves can be found below: If H > 1.792 (A/P), then the grate operates like an orifice; otherwise it operates like a weir. Input Parameters: Type of Grate: Nyloplast 8" Dome Diameter of Grate (ft): 0.666666667 Open Area of Grate (ft2): 0.21 Rim Elevation (ft): 4981.750 Reduction Factor: 50% Depth vs. Flow: Depth Above Inlet (ft) Elevation (ft) Shallow Weir Flow (cfs) Orifice Flow (cfs) Actual Flow (cfs) 0.00 4981.75 0.00 0.00 0.00 0.20 4981.95 0.28 0.25 0.25 0.40 4982.15 0.79 0.36 0.36 0.60 4982.35 1.46 0.44 0.44 0.80 4982.55 2.25 0.50 0.50 1.00 4982.75 3.14 0.56 0.56 1.20 4982.95 4.13 0.62 0.62 1.40 4983.15 5.20 0.67 0.67 1.60 4983.35 6.36 0.71 0.71 1.80 4983.55 7.59 0.76 0.76 2.00 4983.75 8.89 0.80 0.80 Design Flow = 0.22 cfs Q  3 . 0 P H 1 . 5 Q  0 . 67 A ( 2 gH ) 0 . 5 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Discharge (cfs) Stage (ft) Stage - Discharge Curves Weir Flow Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Erosion Control Report APPENDIX C.2 WATER WAWASTORM LINE COMPUTATIONS Downtown Fort Collins Hotel Parking Garage Alternative Preliminary Erosion Control Report MAP POCKET DRAINAGE EXHIBITS S C S H Y D D W D C S G EX. ELEC VAULT RD RD UD UD UD UD UD C T REMMINGTON STREET (100' ROW) 20' WIDE ALLEY EXISTING 1-STORY BRICK BUILDING EXISTING 1-STORY BRICK BUILDING EXISTING 2-STORY BRICK BUILDING OAK STREET (100' ROW) (M) N00°18'49"E 99.99' (R) NORTH 100' (M) S00°20'34"W 99.97' (R) SOUTH 100' (M) N89°42'10"W 69.94' (R) WEST 70' (M) S89°41'11"E 69.99' (R) EAST 70' EXISTING DOOR THRESHOLD ELEV. = 4982.52 EXISTING DOOR THRESHOLD ELEV. = 4982.44 EXISTING DOOR THRESHOLD ELEV. = 4983.99 EXISTING DOOR THRESHOLD ELEV. = 4984.04 EXISTING DOOR THRESHOLD ELEV. = 4982.56 EXISTING DOOR THRESHOLD ELEV. = 4982.46 EXISTING DOOR THRESHOLD ELEV. = 4982.42 EXISTING TREE WELL (TYP.) PRESERVE & PROTECT EXISTING TREE S C S H Y D D W D C S G EX. ELEC VAULT RD RD UD UD UD UD UD C T REMMINGTON STREET (100' ROW) 20' WIDE ALLEY EXISTING 1-STORY BRICK BUILDING EXISTING 1-STORY BRICK BUILDING EXISTING 2-STORY BRICK BUILDING OAK STREET (100' ROW) (M) N00°18'49"E 99.99' (R) NORTH 100' (M) S00°20'34"W 99.97' (R) SOUTH 100' (M) N89°42'10"W 69.94' (R) WEST 70' (M) S89°41'11"E 69.99' (R) EAST 70' EXISTING DOOR THRESHOLD ELEV. = 4982.52 EXISTING DOOR THRESHOLD ELEV. = 4982.44 EXISTING DOOR THRESHOLD ELEV. = 4983.99 EXISTING DOOR THRESHOLD ELEV. = 4984.04 EXISTING DOOR THRESHOLD ELEV. = 4982.56 EXISTING DOOR THRESHOLD ELEV. = 4982.46 EXISTING DOOR THRESHOLD ELEV. = 4982.42 EXISTING TREE WELL (TYP.) PRESERVE & PROTECT EXISTING TREE PRESERVE & PROTECT EX. RAMP WITH HANDRAIL PRESERVE & PROTECT EXISTING TREE PRESERVE & PROTECT EXISTING TREE PRESERVE & PROTECT EXISTING UNDERGROUND ELECTRIC VAULT PRESERVE & PROTECT EXISTING TREE OS-A 0.13 AC. A 0.15 AC. OS-B 0.20 AC. PRESERVE & PROTECT EXISTING TREES B 0.01 AC. OSA OSB A PROPOSED BUILDING FF = 4982.50 PROPOSED STORM SEWER PROPOSED UNDERDRAIN PROPOSED RAIN GARDEN EXISTING DOOR THRESHOLD ELEV. = 4981.46 EXISTING DOOR THRESHOLD ELEV. = 4981.47 RD No. Revisions: By: Date: REVIEWED BY: R. Provencio DESIGNED BY: DRAWN BY: SCALE: DATE: 5/25/2016 PROJECT: 998-002 Sheet Of 13 Sheets POUDRE GARAGE These drawings are instruments of service provided by Northern Engineering Services, Inc. and are not to be used for any type of construction unless signed and sealed by a Professional Engineer in the employ of Northern Engineering Services, Inc. NOT FOR CONSTRUCTION REVIEW SET 5/25/2016 301 North Howes Street, Suite 100 Fort Collins, Colorado 80521 E N G I N E E R I N G N O R T H E RN PHONE: 970.221.4158 www.northernengineering.com Fig.5 with DISTURBED AREA DRAINAGE PLAN F. Wegert F. Wegert 1" = 10' City UTILITY of Fort PLAN Collins, APPROVAL Colorado Date Date Date Date Date Date APPROVED: City Engineer Traffic Engineer Parks & Recreation Stormwater Utility Water & Wastewater Utility CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what'sbelow. Call before you dig. R ( IN FEET ) 10 0 10 20 30 1 INCH = 10 FEET A DRAINAGE BASIN LABEL BASIN DESIGNATION BASIN AREA (AC) DRAINAGE BASIN BOUNDARY B2 1.45 ac 80 79 5015 5013 EXISTING MAJOR CONTOUR EXISTING MINOR CONTOUR PROPOSED CONTOURS DESIGN POINT FLOW ARROWS 1.EXISTING UNDERGROUND AND OVERHEAD PUBLIC AND PRIVATE UTILITIES AS SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT GUARANTEE THE ACCURACY OF SUCH INFORMATION. EXISTING UTILITY MAINS AND SERVICES MAY NOT BE STRAIGHT LINES OR AS INDICATED ON THESE DRAWINGS. THE CONTRACTOR SHALL BE RESPONSIBLE TO CALL ALL UTILITY COMPANIES (PUBLIC AND PRIVATE) PRIOR TO ANY CONSTRUCTION TO VERIFY EXACT UTILITY LOCATIONS. 2.REFER TO THE "FINAL DRAINAGE REPORT FOR POUDRE GARAGE" BY NORTHERN ENGINEERING, DATED MAY 25, 2016 FOR ADDITIONAL INFORMATION. 3.TOTAL DISTURBED AREA FOR PROJECT IS 8,500 FT{}. NOTES: LEGEND: EXISTING RIGHT-OF-WAY/PROPERTY LINE VAULT ELEC EXISTING CONCRETE EXISTING CURB & GUTTER PROPOSED CONCRETE PAVEMENT PROPOSED ASPHALT PAVEMENT PROPOSED VERTICAL CURB & GUTTER RD PROPOSED RAIN GARDEN/LID TREATMENT EXISTING BUILDING SAWCUT LINE EXISTING ELECTRIC VAULT EXISTING FIRE HYDRANT EXISTING TREES PROPOSED ROOF DRAIN PROPOSED BUILDING EXPANSION CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what'sbelow. Call before you dig. R FIELD SURVEY BY: ORIGINAL FIELD SURVEY NORTHERN ENGINEERING SERVICES, INC. PROJECT NUMBER: 998-002 DATE: DECEMBER 2015 PROPOSED STORM SEWER PROPOSED UNDERDRAIN UD DEVELOPED BASIN SUMMARY BASIN ID BASIN AREA (FT 2) BASIN AREA (AC.) % IMPERVIOUS Q 2-YR (CFS) Q 10-YR (CFS) Q 100-YR (CFS) A 6,618 FT2 0.15 ACRES 91.11% 0.24 CFS 0.43 CFS 0.95 CFS B 377 FT2 0.01 ACRES 95.00% 0.02 CFS 0.03 CFS 0.08 CFS OS-A 5,491 FT2 0.13 ACRES 88.31% 0.19 CFS 0.34 CFS 0.75 CFS OS-B 8,929 FT2 0.20 ACRES 93.76% 0.33 CFS 0.59 CFS 1.30 CFS EXISTING BASIN SUMMARY BASIN ID BASIN AREA (FT 2) BASIN AREA (AC.) % IMPERVIOUS Q 2-YR (CFS) Q 10-YR (CFS) Q 100-YR (CFS) A 6,995 FT2 0.16 ACRES 70.95% 0.16 CFS 0.32 CFS 0.75 CFS OS-A 5,491 FT2 0.13 ACRES 94.21% 0.21 CFS 0.38 CFS 0.83 CFS OS-B 8,929 FT2 0.20 ACRES 93.76% 0.33 CFS 0.59 CFS 1.30 CFS TOTAL DISTURBED AREA = 8,500 SQ. FT NEW IMPERVIOUS AREA 3,294 FT2 0.076 AC. TRADITIONAL PAVEMENT AREA 59 FT2 0.001 AC. OTHER IMPERVIOUS SURFACES (ROOFS, CONCRETE, WALKS, ETC.) 3,235 FT2 0.075 AC. REQUIRED MINIMUM IMPERVIOUS AREA TO BE TREATED 2,471 FT2 0.057 AC. REQUIRED MINIMUM VOLUME TO BE TREATED 101 FT3 3.74 YD3 DESIGN VOLUME OF RAIN GARDEN 113 FT3 4.18 YD3 CONTRIBUTING AREA TO RAIN GARDEN 2,471 FT2 0.057 AC. PERCENT OF TREATMENT OF NEW IMPERVIOUS AREA 75% 75% ON-SITE TREATMENT BY LID REQUIREMENTS PRESERVE & PROTECT EX. RAMP WITH HANDRAIL PRESERVE & PROTECT EXISTING TREE PRESERVE & PROTECT EXISTING TREE PRESERVE & PROTECT EXISTING UNDERGROUND ELECTRIC VAULT PRESERVE & PROTECT EXISTING TREE OS-A 0.13 AC. A 0.15 AC. OS-B 0.20 AC. PRESERVE & PROTECT EXISTING TREES B 0.01 AC. OSA OSB A PROPOSED BUILDING FF = 4982.50 PROPOSED STORM SEWER PROPOSED UNDERDRAIN PROPOSED RAIN GARDEN EXISTING DOOR THRESHOLD ELEV. = 4981.46 EXISTING DOOR THRESHOLD ELEV. = 4981.47 RD No. Revisions: By: Date: REVIEWED BY: R. Provencio DESIGNED BY: DRAWN BY: SCALE: DATE: 5/25/2016 PROJECT: 998-002 Sheet Of 13 Sheets POUDRE GARAGE These drawings are instruments of service provided by Northern Engineering Services, Inc. and are not to be used for any type of construction unless signed and sealed by a Professional Engineer in the employ of Northern Engineering Services, Inc. NOT FOR CONSTRUCTION REVIEW SET 5/25/2016 301 North Howes Street, Suite 100 Fort Collins, Colorado 80521 E N G I N E E R I N G N O R T H E RN PHONE: 970.221.4158 www.northernengineering.com C500 DRAINAGE PLAN F. Wegert F. Wegert 1" = 10' City UTILITY of Fort PLAN Collins, APPROVAL Colorado Date Date Date Date Date Date APPROVED: City Engineer Traffic Engineer Parks & Recreation Stormwater Utility Water & Wastewater Utility CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what'sbelow. Call before you dig. R ( IN FEET ) 10 0 10 20 30 1 INCH = 10 FEET A DRAINAGE BASIN LABEL BASIN DESIGNATION BASIN AREA (AC) DRAINAGE BASIN BOUNDARY B2 1.45 ac 80 79 5015 5013 EXISTING MAJOR CONTOUR EXISTING MINOR CONTOUR PROPOSED CONTOURS DESIGN POINT FLOW ARROWS NOTES: LEGEND: EXISTING RIGHT-OF-WAY/PROPERTY LINE VAULT ELEC EXISTING CONCRETE EXISTING CURB & GUTTER PROPOSED CONCRETE PAVEMENT PROPOSED ASPHALT PAVEMENT PROPOSED VERTICAL CURB & GUTTER RD PROPOSED RAIN GARDEN/LID TREATMENT EXISTING BUILDING SAWCUT LINE EXISTING ELECTRIC VAULT EXISTING FIRE HYDRANT EXISTING TREES PROPOSED ROOF DRAIN PROPOSED BUILDING EXPANSION CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what'sbelow. Call before you dig. R FIELD SURVEY BY: ORIGINAL FIELD SURVEY NORTHERN ENGINEERING SERVICES, INC. PROJECT NUMBER: 998-002 DATE: DECEMBER 2015 PROPOSED STORM SEWER PROPOSED UNDERDRAIN UD NEW IMPERVIOUS AREA 3,294 FT2 0.076 AC. TRADITIONAL PAVEMENT AREA 59 FT2 0.001 AC. OTHER IMPERVIOUS SURFACES (ROOFS, CONCRETE, WALKS, ETC.) 3,235 FT2 0.075 AC. REQUIRED MINIMUM IMPERVIOUS AREA TO BE TREATED 2,471 FT2 0.057 AC. REQUIRED MINIMUM VOLUME TO BE TREATED 101 FT3 3.74 YD3 DESIGN VOLUME OF RAIN GARDEN 113 FT3 4.18 YD3 CONTRIBUTING AREA TO RAIN GARDEN 2,471 FT2 0.057 AC. PERCENT OF TREATMENT OF NEW IMPERVIOUS AREA 75% 75% ON-SITE TREATMENT BY LID REQUIREMENTS DEVELOPED BASIN SUMMARY BASIN ID BASIN AREA (FT 2) BASIN AREA (AC.) % IMPERVIOUS Q 2-YR (CFS) Q 10-YR (CFS) Q 100-YR (CFS) A 6,618 FT2 0.15 ACRES 91.11% 0.24 CFS 0.43 CFS 0.95 CFS B 377 FT2 0.01 ACRES 95.00% 0.02 CFS 0.03 CFS 0.08 CFS OS-A 5,491 FT2 0.13 ACRES 88.31% 0.19 CFS 0.34 CFS 0.75 CFS OS-B 8,929 FT2 0.20 ACRES 93.76% 0.33 CFS 0.59 CFS 1.30 CFS EXISTING BASIN SUMMARY BASIN ID BASIN AREA (FT 2) BASIN AREA (AC.) % IMPERVIOUS Q 2-YR (CFS) Q 10-YR (CFS) Q 100-YR (CFS) A 6,995 FT2 0.16 ACRES 70.95% 0.16 CFS 0.32 CFS 0.75 CFS OS-A 5,491 FT2 0.13 ACRES 94.21% 0.21 CFS 0.38 CFS 0.83 CFS OS-B 8,929 FT2 0.20 ACRES 93.76% 0.33 CFS 0.59 CFS 1.30 CFS 1.EXISTING UNDERGROUND AND OVERHEAD PUBLIC AND PRIVATE UTILITIES AS SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT GUARANTEE THE ACCURACY OF SUCH INFORMATION. EXISTING UTILITY MAINS AND SERVICES MAY NOT BE STRAIGHT LINES OR AS INDICATED ON THESE DRAWINGS. THE CONTRACTOR SHALL BE RESPONSIBLE TO CALL ALL UTILITY COMPANIES (PUBLIC AND PRIVATE) PRIOR TO ANY CONSTRUCTION TO VERIFY EXACT UTILITY LOCATIONS. 2.REFER TO THE "FINAL DRAINAGE REPORT FOR POUDRE GARAGE" BY NORTHERN ENGINEERING, DATED MAY 25, 2016 FOR ADDITIONAL INFORMATION. 3.TOTAL DISTURBED AREA FOR PROJECT IS 8,500 FT{}. {4.THE SITE MUST BE SWEPT AND MAINTAINED TO PREVENT DIRT, SAW CUTTINGS, CONCRETE WASH, TRASH & DEBRIS, LANDSCAPE MATERIALS AND OTHER POLLUTANTS FROM ENTERING THE STORM SEWER AT ALL TIMES OR BMP'S WILL BE REQUIRED PER CITY OF FORT COLLINS REGULATIONS.} TOTAL DISTURBED AREA = 8,500 SQ. FT Orifice Flow Orifice Flow Orifice Flow PRESERVE & PROTECT EX. RAMP WITH HANDRAIL PRESERVE & PROTECT EXISTING TREE PRESERVE & PROTECT EXISTING TREE PRESERVE & PROTECT EXISTING UNDERGROUND ELECTRIC VAULT PRESERVE & PROTECT EXISTING TREE OS-A A OS-B PRESERVE & PROTECT EXISTING TREES B OSA OSB A PROPOSED BUILDING FF = 4982.50 PROPOSED STORM SEWER PROPOSED UNDERDRAIN PROPOSED RAIN GARDEN EXISTING DOOR THRESHOLD ELEV. = 4981.46 EXISTING DOOR THRESHOLD ELEV. = 4981.47 RD Sheet Of 13 Sheets POUDRE GARAGE These drawings are instruments of service provided by Northern Engineering Services, Inc. and are not to be used for any type of construction unless signed and sealed by a Professional Engineer in the employ of Northern Engineering Services, Inc. NOT FOR CONSTRUCTION REVIEW SET 301 North Howes Street, Suite 100 Fort Collins, Colorado 80521 E NGINEER ING N O R T H E RN PHONE: 970.221.4158 www.northernengineering.com Fig B.1 with DISTURBED AREA DRAINAGE PLAN CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what'sbelow. Call before you dig. R ( IN FEET ) 10 0 10 20 30 1 INCH = 10 FEET A B2 1.45 ac NOTES: LEGEND: VAULT ELEC RD CALL 2 BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES. CALL UTILITY NOTIFICATION CENTER OF COLORADO Know what'sbelow. Call before you dig. R FIELD SURVEY BY: UD DEVELOPED BASIN SUMMARY BASIN ID BASIN AREA (FT 2) BASIN AREA (AC.) % IMPERVIOUS Q 2-YR (CFS) Q10-YR (CFS) Q100-YR (CFS) A 6,618 FT2 0.15 ACRES 91.11% 0.24 CFS 0.43 CFS 0.95 CFS B 377 FT2 0.01 ACRES 95.00% 0.02 CFS 0.03 CFS 0.08 CFS OS-A 5,491 FT 2 0.13 ACRES 88.31% 0.19 CFS 0.34 CFS 0.75 CFS OS-B 8,929 FT 2 0.20 ACRES 93.76% 0.33 CFS 0.59 CFS 1.30 CFS EXISTING BASIN SUMMARY BASIN ID BASIN AREA (FT 2) BASIN AREA (AC.) % IMPERVIOUS Q 2-YR (CFS) Q10-YR (CFS) Q100-YR (CFS) A 6,995 FT2 0.16 ACRES 70.95% 0.16 CFS 0.32 CFS 0.75 CFS OS-A 5,491 FT2 0.13 ACRES 94.21% 0.21 CFS 0.38 CFS 0.83 CFS OS-B 8,929 FT2 0.20 ACRES 93.76% 0.33 CFS 0.59 CFS 1.30 CFS TOTAL DISTURBED AREA = 8,500 SQ. FT NEW IMPERVIOUS AREA 3,294 FT2 0.076 AC. TRADITIONAL PAVEMENT AREA 59 FT2 0.001 AC. OTHER IMPERVIOUS SURFACES (ROOFS, CONCRETE, WALKS, ETC.) 3,235 FT2 0.075 AC. REQUIRED MINIMUM IMPERVIOUS AREA TO BE TREATED 2,471 FT 2 0.057 AC. REQUIRED MINIMUM VOLUME TO BE TREATED 101 FT3 3.74 YD3 DESIGN VOLUME OF RAIN GARDEN 113 FT3 4.18 YD3 CONTRIBUTING AREA TO RAIN GARDEN 2,471 FT2 0.057 AC. PERCENT OF TREATMENT OF NEW IMPERVIOUS AREA 75% 75% ON-SITE TREATMENT BY LID REQUIREMENTS CONTRIBUTING AREA TO RAIN GARDEN Survey Area Data: Version 10, Sep 22, 2015 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 22, 2011—Apr 28, 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 18 the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 10, Sep 22, 2015 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 22, 2011—Apr 28, 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 9 A A No 0.75 137 0.18% 63.4 0 0.00% N/A N/A 0 0.00% N/A N/A 10.8 10.8 B B No 0.81 8 6.25% 3.9 60 0.83% 1.82 0.5 0 0.00% N/A N/A 10.4 5.0 OS-A OS-A No 0.70 23 1.65% 14.0 93 0.87% 1.87 0.8 0 0.00% N/A N/A 10.6 10.6 OS-B OS-B No 0.78 23 1.65% 11.4 159 0.78% 1.77 1.5 0 0.00% N/A N/A 11.0 11.0 DEVELOPED DIRECT TIME OF CONCENTRATION FOR INDIVIDUAL BASINS Gutter Flow 1 Swale Flow Design Point Basin Overland Flow Time of Concentration Poudre Garage F. Wegert May 25, 2016 (Equation RO-4)   3 1 1 . 87 1 . 1 5 S C L Ti   5/23/2016 9:40 AM D:\Projects\998-002\Drainage\Hydrology\998-002_Post-Developed_UDFCD_RM.xlsx\Tc A A No 0.49 170 0.32% 101.2 0 0.00% N/A N/A 0 0.00% N/A N/A 10.9 10.9 OS-A OS-A No 0.79 23 1.65% 10.8 93 0.87% 1.87 0.8 0 0.00% N/A N/A 10.6 10.6 OS-B OS-B No 0.78 23 1.65% 11.3 159 0.78% 1.77 1.5 0 0.00% N/A N/A 11.0 11.0 EXISTING DIRECT TIME OF CONCENTRATION FOR INDIVIDUAL BASINS Gutter Flow 1 Swale Flow Design Point Basin Overland Flow Time of Concentration Poudre Garage F. Wegert May 25, 2016 (Equation RO-4)   3 1 1 . 87 1 . 1 5 S C L Ti   5/23/2016 9:42 AM D:\Projects\998-002\Drainage\Hydrology\998-002_Pre-Developed_UDFCD_RM.xlsx\Tc