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HomeMy WebLinkAboutHERITAGE PARK - MJA220001 - SUBMITTAL DOCUMENTS - ROUND 2 - DRAINAGE REPORTCity of Fort Collins Heritage Park Apartments (1742 Heritage Circle) Preliminary Drainage Report JULY 2022 Prepared By: 3801 Automation Way, Suite 210 Fort Collins, CO 80525 James Waller Registered Professional Engineer State of Colorado No. 60876 Preliminary Drainage Report Heritage Park Apartments – Fort Collins, Colorado 2 INTRODUCTION The proposed Heritage Park Apartments Improvement Project is located within the Northeast Quarter of Section 22, Township 7 North, Range 69 West of the Sixth Principal Meridian, City of Fort Collins, County of Larimer, Colorado. The site is bound by: · North: Existing Multifamily Development · East: S Shields Street · South: W Stuart Street · West: Existing Multifamily Development A vicinity map is provided below. PROPOSED DEVELOPMENT The site is approximately 16.29 acres and is an existing multifamily development previously known as “Northwood Apartments” per the approved drainage plan dated 7/11/75. The proposed site improvements include six additional dwelling unit buildings with associated driveways and landscape improvements, as well as building and sidewalk additions to the clubhouse under separate permit and submittal. EXISTING SITE INFORMATION The Site is located within the Spring Creek Basin. Existing floodplain boundaries were provided by the City of Fort Collins and are denoted on the proposed drainage map referenced in Appendix B. The Master Plan for this basin is currently planned to be updated in 2022, according to the City of Fort Collins website. Preliminary Drainage Report Heritage Park Apartments – Fort Collins, Colorado 3 Portions of this property are in the city-designated Canal Importation floodplain and floodway. The FEMA FIRM Panel is 08069C0978G dated 5/2/2012. The Canal Importation Basin Master Drainage Plan Hydraulic Evaluation and Mapping Update dated 7/22/14. The Flooding Solutions Map indicates that there are no current upgrades to storm infrastructure near the site. No flooding, water quality, nor Master Plan improvements are recommended within the vicinity of the Site. A proposed linear bioretention and modified detention pond system is located within the existing floodplain. The remaining proposed buildings and scope of site improvements are outside of the 100-year floodplain. No work is proposed within the existing floodway. The soil on the site is primarily Altvan-Satana Loam and Caruso Clay Loam, which are classified as Hydrologic Soil Group B and D, respectively. The soil Classification Map can be found in Appendix A. This Site is a part of the Spring Creek Master Drainage Plan, which is currently under revision and has not been referenced in this design. The existing site is utilized as a multifamily development with associated buildings, parking, and landscape areas. HISTORIC DRAINAGE The existing Site varies with slopes ranging from 1.5% to 35%. There is currently an onsite detention basin in the northeast section of the property. The Site is split into five sub basins, A-1 to A-5, based on the existing drainage map included in Appendix B. Basins A-2, A-3, and A-4 generally slope to the northeast and are conveyed to the existing detention basin within Basin A-4. The flows within the detention basin are then released into the existing storm infrastructure system along S Shields Street. Basins A-1 and A-5 are conveyed south via sheet flow, and collected by existing inlets along W Stuart Street, that convey flows to the existing storm system along S Shields Street. The site is located within City of Fort Collins Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map Number 08069C0978G and the property being developed is designated as an area outside of the 100-year floodplain. The updated FEMA maps is included in Appendix A. Per the FEMA Flood Insurance Rate Map and City of Fort Collins Problem Identification Map, the Site is not within a 100-year floodplain and therefore additional analysis and permitting will not be required. DESIGN CRITERIA The City of Fort Collins “Stormwater Criteria Manual, December 2018 Edition,” (Criteria Manual), the “Urban Drainage and Flood Control District Urban Storm Drainage Criteria Manual” Volumes 1, 2, and 3 (Drainage Manual), with latest revisions, and the “City of Fort Collins Low Impact Development Implementation Manual, July 2017 Edition” (LID Manual) were used to prepare the storm calculations. Weighted impervious values were calculated and used for the site area in accordance with the Criteria Manual and Drainage Manual. This Site is a part of the Spring Creek Master Drainage Plan, which is currently under revision. Existing storm sewer infrastructure is present on the Site. An existing detention pond is present on the northeast corner of the site. Hydrologic Criteria The 2-year and 100-year storm event were evaluated for this Site. Rainfall intensity values provided in the Criteria Manual were utilized for the analysis. Impervious values for pavement, roof, and landscape area Preliminary Drainage Report Heritage Park Apartments – Fort Collins, Colorado 4 were taken from the Criteria Manual. Runoff coefficients were calculated per the Criteria Manual. The Rational Method was utilized to calculate the peak runoff values for the minor and major storm event. Peak runoff values were calculated for the existing and proposed conditions of the Site. Allowable release rates during the 100-year storm event are limited to the 2-year historic release rate, or less, as noted in the applicable Master Drainage Plan for the Canal Importation Drainage Basin. The required minimum detention volume and maximum release rate for the developed condition 100-year recurrence interval storm was determined in accordance with the conditions and regulations established in the Master Drainage Plan and in accordance with the standards noted in the Criteria Manual. Topographic survey of the Site was utilized to delineate existing sub-basins for the Site. An Existing Drainage Map is provided in Appendix B and all hydrologic calculations are provided in Appendix C. Existing sub-basins were maintained for the proposed condition, as shown in the Proposed Drainage Map included in Appendix B. Peak runoff values for the proposed sub-basins were calculated using the Rational Method. Hydrologic calculations are provided in Appendix C. Hydraulic Criteria Water Quality Capture Volumes for sub-basins A, B, C, and D were calculated per the methods described in the Criteria Manual. The Modified FAA Method, as described in the Criteria Manual, was utilized to calculate the required detention volume for the Site in the proposed conditions. Water quality and detention calculations are provided in Appendix D. This Final Drainage Report includes the following hydraulic calculations: inlet calculations; pipe capacity calculations utilizing Bentley FlowMaster. All hydraulic calculations are included in Appendix D. DRAINAGE PLAN GENERAL CONCEPT The Site in the proposed conditions was divided into seven major onsite sub-basins which are described in greater detail in the following section. The sub basin boundaries were maintained from the existing drainage map. SPECIFIC DETAILS Runoff generated by four of the on-site basins (sub-basins A-2, A-3, A-4, and A-6 - 10.19 acres of the total 16.29 acres – 63% of the Site) will be routed to the onsite detention pond. Runoff generated by the remaining sub-basins (sub-basin A-1 and A-5 – 6.10 acres of the total 16.29 acres – 37% of the Site) will follow historic drainage patterns and be routed to the existing storm infrastructure system along W Stuart Street. Discharge rates for sub-basins A-1 and A-5 are accounted for in the pipe sizing calculations provided in Appendix D. The Proposed Drainage Map included in Appendix B shows the onsite sub-basins and each basin is described in further detail below. Table 2 summarizes the tributary areas, impervious areas, imperviousness, and peak flows from each sub-basin. Full calculations are included in Appendix C. Sub-basin A-1 Sub-basin A-1 is 3.70 acres and consists of on-site parking, sidewalk, drive aisles, existing buildings, a portion of the clubhouse building improvement that is being permitted separately, and landscape areas. Flows are conveyed south via sheet flow to the existing inlet along the north side of W Stuart Street. The Preliminary Drainage Report Heritage Park Apartments – Fort Collins, Colorado 5 basin has an imperviousness of 60.7% in the existing condition and is increased to 60.8% in the proposed condition with 26.23 cfs in flows for the 100-year storm. Sub-basin A-2 Sub-basin A-2 is 2.81 acres and consists of on-site parking, sidewalk, drive aisles, existing apartment buildings, proposed apartment buildings, a portion of the clubhouse building improvement that is being permitted separately, and landscape areas. Flows are conveyed northeast via sheet flow to the existing inlet along the north side of Heritage circle, where they are routed through an existing storm pipe to the existing onsite detention pond. The basin has an imperviousness of 42.4% in the existing condition and is increased to 81.9% in the proposed condition with 26.36 cfs in flows for the 100-year storm. Sub-basin A-3 Sub-basin A-3 is 1.75 acres and consists of on-site parking, sidewalk, drive aisles, existing apartment buildings, and landscape areas. Flows are conveyed east via sheet flow to the existing inlet in the parking area within the basin, where they are routed through an existing storm pipe to the existing onsite detention pond. No improvements are proposed within basin A-3 so the runoff and imperviousness for the basin remain unchanged in the proposed condition. The basin has an imperviousness of 62.4% in the existing and proposed condition with 11.68 cfs in flows for the 100-year storm. Sub-basin A-4 Sub-basin A-4 is 3.45 acres and consists of existing apartment buildings, concrete recreation areas, landscape areas, and the existing onsite detention pond. Flows are conveyed east via sheet flow to the existing detention pond scheduled to be improved with this development. Improvements to the existing detention pond include increased capacity, proposed 6” perforated underdrain, proposed Type L 12” riprap, proposed concrete trickle channel, and proposed connection to the existing storm sewer network along S Shields Street. The basin has an imperviousness of 7.1% in the existing condition and is increased to 7.8% in the proposed condition with 7.50 cfs in flows for the 100-year storm. Sub-basin A-5 Sub-basin A-5 is 2.40 acres and consists of on-site parking, sidewalk, drive aisles, existing apartment buildings, proposed apartment buildings, and landscape areas. Flows are conveyed south via sheet flow to the existing inlet in the southern parking area, where they are routed through an existing storm pipe to the existing storm system along S Shields Street. The basin has an imperviousness of 60.2% in the existing condition and is increased to 68.7% in the proposed condition with 18.55 cfs in flows for the 100-year storm. Sub-basin A-6 Sub-basin A-6 is 2.18 acres and consists of on-site parking, sidewalk, drive aisles, existing apartment buildings, and landscape areas. Flows are conveyed northeast via sheet flow to the proposed curb cut along the north side of Heritage circle, where they are routed through a proposed 6” perforated underdrain to the existing onsite detention pond. No improvements are proposed within basin A-6 so the runoff and imperviousness for the basin remain unchanged in the proposed condition. The basin has an imperviousness of 50.5% in the existing and proposed condition with 11.24 cfs in flows for the 100-year storm. Preliminary Drainage Report Heritage Park Apartments – Fort Collins, Colorado 6 Sub-basin OS-1 Sub-basin OS-1 is 1.58 acres off-site and consists of sidewalk, drive aisles, and landscape areas. Flows are conveyed south via sheet flow to the existing inlet along the north side of W Stuart Street. No improvements are proposed within basin OS-1 so the runoff and imperviousness for the basin remain unchanged in the proposed condition. The basin has an imperviousness of 85.3% in the existing and proposed condition with 14.01 cfs in flows for the 100-year storm. Table 2. Summary of proposed drainage sub-basins. Basin ID Total Tributary Area (acres) Impervious Area (acres)1 Imperviousness 2-Year Peak Flow (CFS) 100-Year Peak Flow (CFS) A-1 3.70 2.25 60.8%6.99 26.23 A-2 2.81 2.30 81.9%7.03 26.36 A-3 1.75 1.09 62.4%3.37 11.68 A-4 3.45 0.27 7.8%1.75 7.50 A-5 2.40 1.65 68.7%4.97 18.55 A-6 2.18 1.10 50.5%2.89 11.24 OS-13 1.58 1.35 85.3%3.77 14.01 Total On-Site 16.29 8.66 53.10%27.00 101.56 Total On-Site to Detention2 10.19 4.76 50.63%3.76 14.20 1. Includes pavement and roof areas. 2.Includes A-2, A-3, A-4, and A-6. 3.Off-site runoff. Preliminary Drainage Report Heritage Park Apartments – Fort Collins, Colorado 7 Existing Detention Pond There is an existing detention pond in the northeast corner of the site placed to detain site flows from the 100-year storm event to the 2-year historic release rate. The existing detention pond has capacity to hold 0.767 acre-ft. The proposed site improvements require a 100-year storage volume of 1.088 acre-feet. Since the existing detention pond does not have capacity for the increase in flows, improvements are proposed to increase the storage volume of the detention pond. The proposed pond improvements will increase the storage capacity of the pond to 1.089 acre-feet at the 100-year water surface elevation. A proposed concrete trickle channel, outlet structure, and 10” PVC storm sewer tie-in connection to the existing storm sewer in S Shields Avenue have been added to maintain historic flood rates. Additionally, a restrictor plate will be added to the proposed outlet structure to maintain historic flow rates and provide a 40 hour drain time for the detention pond. Runoff from sub-basins A-2, A-3, A-4, and A-6 will be routed via sheet flow and existing storm sewer infrastructure to enter the proposed linear bioretention system and are conveyed to the modified detention pond system before being released into the existing public storm sewer that outfalls to Spring Creek. The proposed detention pond improvements are designed for water quality per Section 6.5 (Linear Bioretention - Low Impact Development) of Chapter 7 of the Fort Collins. Reference to the criteria used for design of the linear bioretention system can be found in Appendix E. Table 6. Comparison of pond elevations and water surface elevations. Pond Bottom Elevation 5014.00 Pond Bottom Elevation at Outlet Structure 5014.00 Water Quality Control Volume Surface Elevation 5015.40 100-Year Water Surface Elevation 5017.80 Pond Crest of Spillway Elevation 5018.20 A 2-foot-wide concrete V trickle channel conveys flows at 1.0% slope from the inflow points to the outlet structure. The trickle channel flows to the existing outlet pipe with the proposed restrictor plate. A restrictor plate over the outlet pipe (15-inch RCP) is required to ensure the 100-year release rate is met. Storm Sewer Conveyance No new storm sewer infrastructure is proposed with the site improvements. The existing storm pipes conveying flows to the existing storm system along S Shields Street have capacity for the increase in flow, except for the pipe conveying flows from basin A-5 to the greater system. Based on the existing drainage map for “Northwood Apartments”, the pipe was sized to convey flows from the 50-year storm. In the proposed condition, the pipe does not have capacity for the 0.48 cfs flow increase in the minor storm, so the existing 10” VCP storm pipe is proposed to be upsized to a 15” RCP storm pipe to handle the increase in flows. All existing storm pipes to remain are sized to handle the increase in flows, apart from A-5. Pipe Sizing calculations are provided in Appendix D. Inlet Capacity The capacity of each affected existing inlet was evaluated to determine the maximum ponding depth to convey the 100-year storm event. The results of the capacity analysis indicate that two of the affected inlets Preliminary Drainage Report Heritage Park Apartments – Fort Collins, Colorado 8 do not have capacity for the increase in flows, and the remaining inlet has capacity for the minor storm flow increase. Flows are conveyed from Sub-basin A-1 and OS-1 to the existing 5’ Type R inlet along the north edge of W Stuart Street. Based on calculations, the existing inlet does not have capacity to handle the flows from the major or minor storm in the proposed and the existing condition. To handle the existing and proposed condition, the existing inlet will need to be improved in the final drainage report and construction documents to be (4) 5’ Type R inlets. Flows are conveyed from Sub-basin A-2 to the existing 5’ Type R inlet along the north side of Heritage Circle. Based on the existing drainage map for “Northwood Apartments”, the inlet was sized to convey flows from the major and minor storm. In the proposed condition, the inlet has capacity for the flow increase in the minor storm. During the major storm event, flows that spill over the existing inlet will flow into the existing detention pond. Flows are conveyed from Sub-basin A-5 to the existing 5’ Type R inlet along the southern parking area. Based on the existing drainage map for “Northwood Apartments”, the inlet was sized to convey flows from the major and minor storm. Based on calculations, the existing inlet does not have capacity to handle the flows from the major or minor storm in the proposed and the existing condition. The inlet will need to be improved in order to handle current condition flows as well as proposed. To handle the existing and proposed condition, the existing inlet will need to be improved in the final drainage report and construction documents to be (2) 5’ Type R inlets. Low Impact Development (LID) and Water Quality The site was divided into five onsite sub-basins which are described in greater detail in the sections above. BMPs were selected utilizing the four-step process outlined in Volume 3, Chapter 1, Section 4 of the Drainage Manual: 1. Employ runoff reduction practices - The redevelopment on an existing multi-family site provides limited opportunities to employ runoff reduction practices. Site has been developed to install landscaping wherever pavement (or building) is not required. 2. Implement BMPs that provide a water quality capture volume with a slow release – the site will be treated with a linear bioretention system. 3. Stabilize streams – Not applicable. 4. Implement site specific and other source control BMPs – No trash collection or enclosed areas are proposed within proximity to storm drainage or LID facilities. Highly concentrated and polluted runoff from these areas will have the opportunity to be cleaned prior to runoff into the applicable storm drains. The site will be surrounded by silt fence to reduce potential for contamination discharges at the perimeter. Site access will be provided through an area of vehicle tracking control to reduce tracking of contamination offsite which will be further controlled with street sweeping. Existing storm sewer will have inlet protection to guard Spring Creek from any contamination. Stockpiles and staged material during construction will be located away from all storm drainage facilities. Runoff generated by a portion of these drainage basins will be conveyed into the proposed linear bioretention system and conveyed to the modified detention pond system before being released into the existing public storm sewer that outfalls to Spring Creek. Runoff generated by four of the on-site basins (sub-basins A-2, A-3, A-4, and A-6 - 10.19 acres of the total 16.29 acres – 63% of the Site) will be routed to the onsite detention pond. The overall imperviousness area for the site will increase 1.52 acres from the Preliminary Drainage Report Heritage Park Apartments – Fort Collins, Colorado 9 existing to proposed condition. 1.31 acres or 86% of the additional imperviousness area for the site will be routed to the proposed bioretention system and conveyed to the modified detention pond system. Reference to the criteria used for design of the linear bioretention system can be found in Appendix E. Overall imperviousness of the site will increase from 43.8% to 53.1%. 55% of the imperviousness will be treated for water quality by the proposed linear bioretention pond. The remaining runoff from sub-basins A- 1 and A-5 will follow historic drainage patterns and enter the existing public storm sewer that outfalls to Spring Creek. The proposed pond improvements are designed for water quality per Section 6.5 (Linear Bioretention - Low Impact Development) of Chapter 7 of the Fort Collins. The proposed pond improvements have low longitudinal slopes and broad cross-sections that convey flow in a slow and shallow manner, thereby facilitating sedimentation and filtering while limiting erosion. Additionally, Type L 12” riprap is included with the proposed pond improvements to reduce velocities and improve both suspended particle settling and infiltration. Stormwater Criteria Manual (Water Quality) Table 6 summarizes the pond bottom elevation, water surface elevation, and spillway elevation. Detention pond and outlet structure calculations are provided in Appendix D. VARIANCE REQUESTS No variances are being requested. CONCLUSIONS COMPLIANCE WITH STANDARDS The Mulberry Connection project is in compliance with City of Fort Collins criteria for storm drainage design. The “Fort Collins Stormwater Criteria Manual, December 2018 Edition,” and the Urban Drainage Flood Control District “Urban Storm Drainage Criteria Manual Volumes 1, 2, and 3 have been utilized for reference. SUMMARY OF CONCEPT The proposed drainage concept is maintaining historic drainage patterns and provide improvements to the existing drainage pond and storm pipe. Improvements to the existing detention pond are proposed to detain the on-site 100-year runoff volume to the 2-year historic on-site flow. Allowable release rates are designed based on the existing condition in accordance the Master Drainage Plan and standards noted in the Criteria Manual. Downstream impacts due to the development of this Site are not anticipated. REFERENCES Fort Collins Stormwater Criteria Manual, December 2018 Edition, City of Fort Collins. Urban Storm Drainage Criteria Manual, Volume 1-3, Mile High Flood District, Denver, CO; January 2016, with latest revisions. Low Impact Development Implementation Manual, City of Fort Collins, Fort Collins, CO; July 2017. Northwood Apartments Contour Map, Freese Engineering Consultants, Greeley, CO; July 1975 Preliminary Drainage Report Heritage Park Apartments – Fort Collins, Colorado 10 APPENDICES A. NRCS Data and FEMA Map B. Existing and Proposed Drainage Map C. Hydrologic Calculations D. Hydraulic Calculations E. Low Impact Development Reference Material 11 APPENDIX A National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V, A99 With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mileZone X Future Conditions 1% Annual Chance Flood HazardZone X Area with Reduced Flood Risk due to Levee. See Notes.Zone X Area with Flood Risk due to LeveeZone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood HazardZone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 3/15/2022 at 5:41 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. 1:6,000 105°6'11"W 40°34'6"N 105°5'34"W 40°33'39"N Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020 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 Area, ColoradoNatural Resources Conservation Service March 15, 2022 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 (https://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 2 alternative means 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..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................11 Map Unit Descriptions.........................................................................................11 Larimer County Area, Colorado......................................................................13 3—Altvan-Satanta loams, 0 to 3 percent slopes.........................................13 4—Altvan-Satanta loams, 3 to 9 percent slopes.........................................15 22—Caruso clay loam, 0 to 1 percent slope...............................................17 References............................................................................................................19 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 5 scientists classified and named the soils in the survey area, they compared the 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 Custom Soil Resource Report 6 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 7 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. 8 9 Custom Soil Resource Report Soil Map 449028044903304490380449043044904804490530449058044906304490680449028044903304490380449043044904804490530449058044906304490680491570 491620 491670 491720 491770 491820 491870 491570 491620 491670 491720 491770 491820 491870 40° 34' 1'' N 105° 5' 59'' W40° 34' 1'' N105° 5' 45'' W40° 33' 46'' N 105° 5' 59'' W40° 33' 46'' N 105° 5' 45'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 100 200 400 600 Feet 0 30 60 120 180 Meters Map Scale: 1:2,180 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. 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: 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 Survey Area Data: Version 16, Sep 2, 2021 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 11, 2018—Aug 12, 2018 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 10 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 3 Altvan-Satanta loams, 0 to 3 percent slopes 8.9 51.0% 4 Altvan-Satanta loams, 3 to 9 percent slopes 7.6 43.3% 22 Caruso clay loam, 0 to 1 percent slope 1.0 5.7% Totals for Area of Interest 17.5 100.0% 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 Custom Soil Resource Report 11 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 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 12 Larimer County Area, Colorado 3—Altvan-Satanta loams, 0 to 3 percent slopes Map Unit Setting National map unit symbol: jpw2 Elevation: 5,200 to 6,200 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 Altvan and similar soils:45 percent Satanta and similar soils:30 percent Minor components:25 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Altvan Setting Landform:Terraces, benches Landform position (three-dimensional):Side slope, tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Mixed alluvium Typical profile H1 - 0 to 10 inches: loam H2 - 10 to 18 inches: clay loam H3 - 18 to 30 inches: loam H4 - 30 to 60 inches: gravelly sand Properties and qualities Slope:0 to 3 percent Depth to restrictive feature:More than 80 inches 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 content:10 percent Available water supply, 0 to 60 inches: Low (about 5.4 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Ecological site: R067BY002CO - Loamy Plains Hydric soil rating: No Custom Soil Resource Report 13 Description of Satanta Setting Landform:Structural benches, 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 9 inches: loam H2 - 9 to 18 inches: loam H3 - 18 to 60 inches: loam Properties and qualities Slope:0 to 1 percent Depth to restrictive feature:More than 80 inches 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 content:10 percent Available water supply, 0 to 60 inches: High (about 10.1 inches) Interpretive groups Land capability classification (irrigated): 1 Land capability classification (nonirrigated): 3c Hydrologic Soil Group: B Ecological site: R067BY002CO - Loamy Plains Hydric soil rating: No Minor Components Nunn Percent of map unit:10 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Larim Percent of map unit:10 percent Ecological site:R067BY063CO - Gravel Breaks Hydric soil rating: No Stoneham Percent of map unit:5 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Custom Soil Resource Report 14 4—Altvan-Satanta loams, 3 to 9 percent slopes Map Unit Setting National map unit symbol: jpwf Elevation: 5,200 to 6,200 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: Farmland of statewide importance Map Unit Composition Altvan and similar soils:55 percent Satanta and similar soils:35 percent Minor components:10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Altvan Setting Landform:Terraces, benches, fans Landform position (three-dimensional):Side slope, base slope, tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Mixed alluvium Typical profile H1 - 0 to 9 inches: loam H2 - 9 to 16 inches: clay loam H3 - 16 to 31 inches: loam H4 - 31 to 60 inches: gravelly sand Properties and qualities Slope:6 to 9 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Medium 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 content:10 percent Available water supply, 0 to 60 inches: Low (about 5.5 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: R067BY008CO - Loamy Slopes Custom Soil Resource Report 15 Hydric soil rating: No Description of Satanta Setting Landform:Terraces, structural benches 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 9 inches: loam H2 - 9 to 14 inches: loam H3 - 14 to 60 inches: loam Properties and qualities Slope:3 to 6 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Medium 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 content:10 percent Available water supply, 0 to 60 inches: High (about 10.1 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Ecological site: R067BZ902CO - Loamy Plains Hydric soil rating: No Minor Components Nunn Percent of map unit:6 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Larimer Percent of map unit:4 percent Ecological site:R067BZ902CO - Loamy Plains Hydric soil rating: No Custom Soil Resource Report 16 22—Caruso clay loam, 0 to 1 percent slope Map Unit Setting National map unit symbol: jpvt Elevation: 4,800 to 5,500 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 Caruso and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Caruso Setting Landform:Flood-plain steps, stream terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Mixed alluvium Typical profile H1 - 0 to 35 inches: clay loam H2 - 35 to 44 inches: fine sandy loam H3 - 44 to 60 inches: gravelly sand Properties and qualities Slope:0 to 1 percent Depth to restrictive feature:More than 80 inches Drainage class:Somewhat poorly drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat):Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table:About 24 to 48 inches Frequency of flooding:NoneOccasional Frequency of ponding:None Calcium carbonate, maximum content:5 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water supply, 0 to 60 inches: Moderate (about 8.4 inches) Interpretive groups Land capability classification (irrigated): 3w Land capability classification (nonirrigated): 5w Hydrologic Soil Group: D Ecological site: R067BY036CO - Overflow Hydric soil rating: No Custom Soil Resource Report 17 Minor Components Loveland Percent of map unit:9 percent Landform:Terraces Ecological site:R067BY036CO - Overflow Hydric soil rating: Yes Fluvaquents Percent of map unit:6 percent Landform:Terraces Hydric soil rating: Yes Custom Soil Resource Report 18 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 19 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 20 12 APPENDIX B R Know what's below. Call before you dig.HERITAGE PARK APARTMENTSFORT COLLINS, COLORADOMAJOR AMENDMENT©FOR REVIEW ONLY NOT FOR Kimley-Horn and Associates, Inc. CONSTRUCTION LEGEND: GENERAL NOTES:PROPOSED DRAINAGE MAP4 NORTHS SHIELDS ST100' R.O.W.HERITAGE CIRCLE TO BE VACATED UNDER SEPARATE PERMIT W STUART ST 80' R.O.W. 13 APPENDIX C 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Rainfall Intensity TIME 2 YR 10 YR 100 YR 5 2.85 4.87 9.95 6 2.67 4.56 9.31 7 2.52 4.31 8.80 8 2.40 4.10 8.38 9 2.30 3.93 8.03 10 2.21 3.78 7.72 11 2.13 3.63 7.42 12 2.05 3.50 7.16 13 1.98 3.39 6.92 14 1.92 3.29 6.71 15 1.87 3.19 6.52 20 1.61 2.74 5.60 25 1.43 2.44 4.98 30 1.30 2.21 4.52 40 1.07 1.83 3.74 50 0.92 1.58 3.23 60 0.82 1.40 2.86 120 0.49 0.86 1.84 Note: Time Intensity Frequency Tabulation Intensity values from the City of Fort Collins Intensity-Duration-Frequency Tables; Chapter 5, Section 3.4 of the Fort Collins Stormwater Criteria Manual, 2018 Edition. K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\EX CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Existing Imperviousness and Runoff Coefficient Calculations Basin A-1 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 62,080 39%2%0.20 0.20 0.25 Rooftop 25,673 16%90%0.95 0.95 1.00 Asphalt, Concrete 73,398 46%100%0.95 0.95 1.00 161,151 100%61%0.66 0.66 0.71 Basin A-2 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 125,704 58%2%0.20 0.20 0.25 Rooftop 20,579 9%90%0.95 0.95 1.00 Asphalt, Concrete 71,081 33%100%0.95 0.95 1.00 217,364 100%42%0.52 0.52 0.57 Basin A-3 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 27,835 37%2%0.20 0.20 0.25 Rooftop 13,580 18%90%0.95 0.95 1.00 Asphalt, Concrete 34,699 46%100%0.95 0.95 1.00 76,114 100%62%0.68 0.68 0.73 Basin A-4 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 142,106 94%2%0.20 0.20 0.25 Rooftop 5,069 3%90%0.95 0.95 1.00 Asphalt, Concrete 3,309 2%100%0.95 0.95 1.00 150,484 100%7%0.24 0.24 0.29 Basin A-5 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 40,711 39%2%0.20 0.20 0.25 Rooftop 16,608 16%90%0.95 0.95 1.00 Asphalt, Concrete 47,133 45%100%0.95 0.95 1.00 104,452 100%60%0.66 0.66 0.71 Notes: 1. Imperviousness, I, values per UDFCD Criteria Manual Volume 1, Table 6-3 2. Runoff Coefficient values are from the City of Fort Collins Runoff Coefficient Tables 3.2-2 and 3.2-3; Chapter 5, Section 3.2 of the Fort Collins Stormwater Criteria Manual, 2018 Edition. K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\EX CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Existing Time of Concentration (2-Year Design Storms) A-1 A-1 161,151 3.70 61%0.66 53 15.5%2.4 735 1.2%0.195 4.2 2.9 5.3 788 14.4 5.3 A-2 A-2 217,364 4.99 42%0.52 266 10.0%8.3 528 1.5%0.195 4.7 1.9 10.2 794 14.4 10.2 A-3 A-3 76,114 1.75 62%0.68 123 6.8%4.6 254 8.0%0.195 10.9 0.4 5.0 377 12.1 5.0 A-4 A-4 150,484 3.45 7%0.24 229 8.1%12.1 142 8.0%0.195 10.9 0.2 5.0 371 12.1 5.0 A-5 A-5 104,452 2.40 60%0.66 29 8.0%2.2 156 1.0%0.195 3.9 0.7 5.0 185 11.0 5.0 TOTAL 709,565 16.29 *Tc has been overwritten to 5 minutes due to basin size. SUB-BASIN DATA DESIGN POINT DRAIN BASIN AREA (SF) AREA (AC) RUNOFF COEFFICIENT I (%) Slope (%)TI LENGTH (FT) Slope (%)RC2/10 DESIGN TC (2-YR) INITIAL / OVERLAND TIME TI Velocity (FPS)TT TC LENGTH (FT)L/180+10 TRAVEL TIME TT URBANIZED BASIN CHECK TC LENGTH (FT) K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\EX CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Existing Time of Concentration (100-Year Design Storms) A-1 A-1 161,151 3.70 61%0.71 53 15.5%2.1 735 1.2%0.195 4.2 2.9 5.0 788 14.4 5.0 A-2 A-2 217,364 4.99 42%0.57 266 10.0%7.6 528 1.5%0.195 4.7 1.9 9.5 794 14.4 9.5 A-3 A-3 76,114 1.75 62%0.73 123 2.4%5.8 254 8.0%0.195 10.9 0.4 5.0 377 12.1 5.0 A-4 A-4 150,484 3.45 7%0.29 229 8.1%11.4 142 8.0%0.195 10.9 0.2 5.0 371 12.1 5.0 A-5 A-5 104,452 2.40 60%0.71 29 8.0%2.0 156 1.0%0.195 3.9 0.7 5.0 185 11.0 5.0 TOTAL 709,565 16.29 *Tc has been overwritten to 5 minutes due to basin size. SUB-BASIN DATA RUNOFF COEFFICIENT INITIAL / OVERLAND TIME TI TRAVEL TIME TT URBANIZED BASIN CHECK TC DESIGN TC (100- YR)DESIGN POINT DRAIN BASIN AREA (SF) AREA (AC) I (%)C100 LENGTH (FT) Slope (%)TI LENGTH (FT)L/180+10Slope (%)R Velocity (FPS)TT TC LENGTH (FT) K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\EX CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Existing Runoff Calculations 2-Year Design Storm Runoff Calculations (Rational Method Procedure) A-1 A-1 3.70 0.66 5.3 2.45 2.80 6.84 A-2 A-2 4.99 0.52 10.2 2.58 2.20 5.66 A-3 A-3 1.75 0.68 5.0 1.18 2.85 3.37 A-4 A-4 3.45 0.24 5.0 0.84 2.85 2.38 A-5 A-5 2.40 0.66 5.0 1.58 2.85 4.49 TOTAL 16.29 22.74 Q (CFS) I (IN/HR) ∑ C*ATC Q (CFS) AREA (AC) REMARKS BASIN INFORMATON TOTAL RUNOFF DESIGN POINT DIRECT RUNOFF I (IN/HR) ∑ C*ATCC2 DRAIN BASIN K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\EX CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Existing Runoff Calculations 100-Year Design Storm Runoff Calculations (Rational Method Procedure) A-1 A-1 3.70 0.71 5.0 2.63 9.95 26.17 A-2 A-2 4.99 0.57 9.5 2.83 7.89 22.28 A-3 A-3 1.75 0.73 5.0 1.27 9.95 12.62 A-4 A-4 3.45 0.29 5.0 1.01 9.95 10.03 A-5 A-5 2.40 0.71 5.0 1.70 9.95 16.88 TOTAL 16.29 0.58 87.98 DIRECT RUNOFF Q (CFS) BASIN INFORMATON TOTAL RUNOFF REMARKSDESIGN POINT DRAIN BASIN AREA (AC)C100 TC I (IN/HR) ∑ C*A I (IN/HR) Q (CFS)TC ∑ C*A K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\EX CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Existing Imperviousness and Runoff Coefficient Summary A-1 A-1 3.70 23%60.7%13.8%2.24 0.66 0.71 A-2 A-2 4.99 31%42.4%13.0%2.11 0.52 0.57 A-3 A-3 1.75 11%62.4%6.7%1.09 0.68 0.73 A-4 A-4 3.45 21%7.1%1.5%0.25 0.24 0.29 A-5 A-5 2.40 15%60.2%8.9%1.44 0.66 0.71 16.29 100%43.8%7.14 WEIGHTED (%) TOTAL Impervious Area (Ac)C2 C100 DESIGN POINT DRAIN BASIN AREA (AC) % of Site (%) I (%) K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\EX CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Existing Direct Runoff Summary Standard Rational Method A-1 A-1 3.70 6.84 26.17 A-2 A-2 4.99 5.66 22.28 A-3 A-3 1.75 3.37 12.62 A-4 A-4 3.45 2.38 10.03 A-5 A-5 2.40 4.49 16.88 16.29 22.74 87.98 Q100 (CFS) Q2 (CFS) DESIGN POINT DRAIN BASIN AREA (AC) K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\EX CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Rainfall Intensity TIME 2 YR 10 YR 100 YR 5 2.85 4.87 9.95 6 2.67 4.56 9.31 7 2.52 4.31 8.80 8 2.40 4.10 8.38 9 2.30 3.93 8.03 10 2.21 3.78 7.72 11 2.13 3.63 7.42 12 2.05 3.50 7.16 13 1.98 3.39 6.92 14 1.92 3.29 6.71 15 1.87 3.19 6.52 20 1.61 2.74 5.60 25 1.43 2.44 4.98 30 1.30 2.21 4.52 40 1.07 1.83 3.74 50 0.92 1.58 3.23 60 0.82 1.40 2.86 120 0.49 0.86 1.84 Note: Time Intensity Frequency Tabulation Intensity values from the City of Fort Collins Intensity-Duration-Frequency Tables; Chapter 5, Section 3.4 of the Fort Collins Stormwater Criteria Manual, 2018 Edition. K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Proposed Imperviousness and Runoff Coefficient Calculations Basin A-1 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 61,820 38%2%0.20 0.20 0.25 Rooftop 26,087 16%90%0.95 0.95 1.00 Asphalt, Concrete 73,306 45%100%0.95 0.95 1.00 161,213 100%61%0.66 0.66 0.71 Basin A-2 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 57,699 47%2%0.20 0.20 0.25 Rooftop 20,563 17%90%0.95 0.95 1.00 Asphalt, Concrete 80,423 66%100%0.95 0.95 1.00 122,276 130%82%0.88 0.88 0.94 Basin A-3 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 27,835 37%2%0.20 0.20 0.25 Rooftop 13,581 18%90%0.95 0.95 1.00 Asphalt, Concrete 34,698 46%100%0.95 0.95 1.00 76,114 100%62%0.68 0.68 0.73 Basin A-4 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 140,867 94%2%0.20 0.20 0.25 Rooftop 6,783 5%90%0.95 0.95 1.00 Asphalt, Concrete 2,836 2%100%0.95 0.95 1.00 150,486 100%8%0.25 0.25 0.30 Basin A-5 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 30,989 30%2%0.20 0.20 0.25 Rooftop 23,357 22%90%0.95 0.95 1.00 Asphalt, Concrete 50,107 48%100%0.95 0.95 1.00 104,453 100%69%0.73 0.73 0.78 Basin A-6 Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 46,765 49%2%0.20 0.20 0.25 Rooftop 12,668 13%90%0.95 0.95 1.00 Asphalt, Concrete 35,641 37%100%0.95 0.95 1.00 95,074 100%50%0.58 0.58 0.63 Basin OS-1 (Off-site)Area (sf)Basin %I C2 C10 C100 Lawns, Clayey Soil 10,355 15%2%0.20 0.20 0.25 Rooftop 0 0%90%0.95 0.95 1.00 Asphalt, Concrete 58,542 85%100%0.95 0.95 1.00 68,897 100%85%0.84 0.84 0.89 Notes: 1. Imperviousness, I, values per UDFCD Criteria Manual Volume 1, Table 6-3 2. Runoff Coefficient values are from the City of Fort Collins Runoff Coefficient Tables 3.2-2 and 3.2-3; Chapter 5, Section 3.2 of the Fort Collins Stormwater Criteria Manual, 2018 Edition. K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Proposed Time of Concentration (2-Year Design Storms) A-1 A-1 161,213 3.70 61%0.66 96 12.8%3.4 468 7.4%0.195 10.5 0.7 5.0 564 13.1 5.0 A-2 A-2 122,276 2.81 82%0.88 155 2.7%3.7 369 2.5%0.195 6.1 1.0 5.0 524 12.9 5.0 A-3 A-3 76,114 1.75 62%0.68 123 6.8%4.6 254 8.0%0.195 10.9 0.4 5.0 377 12.1 5.0 A-4 A-4 150,486 3.45 8%0.25 229 8.1%12.0 142 8.0%0.195 10.9 0.2 12.2 371 12.1 12.1 A-5 A-5 104,453 2.40 69%0.73 0 0.0%0.0 237 2.0%0.195 5.5 0.7 5.0 237 11.3 5.0 A-6 A-6 95,074 2.18 50%0.58 121 4.2%6.6 730 1.4%0.195 4.6 2.6 9.2 851 14.7 9.2 709,616 16.29 Off-site flows directed to Type R inlet along north frontage of W Stuart Street OS-1 OS-1 68,897 1.58 85%0.84 0 0.0%0.0 767 5.4%0.195 9.0 1.4 5.0 767 14.3 5.0 *Tc has been overwritten to 5 minutes due to basin size. DESIGN TC (2-YR) INITIAL / OVERLAND TIME TI Velocity (FPS)TT TC LENGTH (FT)L/180+10 TRAVEL TIME TT URBANIZED BASIN CHECK TC LENGTH (FT) Slope (%)TI LENGTH (FT) Slope (%)RC2/10 SUB-BASIN DATA DESIGN POINT DRAIN BASIN AREA (SF) AREA (AC) RUNOFF COEFFICIENT I (%) K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Proposed Time of Concentration (100-Year Design Storms) A-1 A-1 161,213 3.70 61%0.71 96 12.8%3.0 468 7.4%0.195 10.5 0.7 5.0 564 13.1 5.0 A-2 A-2 122,276 2.81 82%0.94 155 2.7%2.6 369 2.5%0.195 6.1 1.0 5.0 524 12.9 5.0 A-3 A-3 76,114 1.75 62%0.73 123 2.4%5.8 254 8.0%0.195 10.9 0.4 6.2 377 12.1 6.2 A-4 A-4 150,486 3.45 8%0.30 229 8.1%11.3 142 8.0%0.195 10.9 0.2 11.5 371 12.1 11.5 A-5 A-5 104,453 2.40 69%0.78 0 0.0%0.0 237 2.0%0.195 5.5 0.7 5.0 237 11.3 5.0 A-6 A-6 95,074 2.18 50%0.63 121 4.2%6.0 730 1.4%0.195 4.6 2.6 8.6 851 14.7 8.6 709,616 16.29 Off-site flows directed to Type R inlet along north frontage of W Stuart Street OS-1 OS-1 68,897 1.58 85%0.89 0 0.0%0.0 767 5.4%0.195 9.0 1.4 5.0 767 14.3 5.0 *Tc has been overwritten to 5 minutes due to basin size. L/180+10Slope (%)R Velocity (FPS)TT TC LENGTH (FT) I (%)C100 LENGTH (FT) Slope (%)TI LENGTH (FT) SUB-BASIN DATA RUNOFF COEFFICIENT INITIAL / OVERLAND TIME TI TRAVEL TIME TT URBANIZED BASIN CHECK TC DESIGN TC (100- YR)DESIGN POINT DRAIN BASIN AREA (SF) AREA (AC) K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Proposed Runoff Calculations 2-Year Design Storm Runoff Calculations (Rational Method Procedure) A-1 A-1 3.70 0.66 5.0 2.45 2.85 6.99 A-2 A-2 2.81 0.88 5.0 2.47 2.85 7.03 A-3 A-3 1.75 0.68 5.0 1.18 2.85 3.37 A-4 A-4 3.45 0.25 12.1 0.86 2.04 1.75 A-5 A-5 2.40 0.73 5.0 1.74 2.85 4.97 A-6 A-6 2.18 0.58 9.2 1.27 2.28 2.89 16.29 27 Off-site flows directed to Type R inlet along north frontage of W Stuart Street OS-1 OS-1 1.58 0.84 5.0 1.32 2.85 3.77 REMARKS BASIN INFORMATON TOTAL RUNOFF DESIGN POINT DIRECT RUNOFF 1.00∑ C*ATCC2 DRAIN BASIN Q (CFS) I (IN/HR) ∑ C*ATC Q (CFS) AREA (AC) K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Proposed Runoff Calculations 100-Year Design Storm Runoff Calculations (Rational Method Procedure) A-1 A-1 3.70 0.71 5.0 2.64 9.95 26.23 A-2 A-2 2.81 0.94 5.0 2.65 9.95 26.36 A-3 A-3 1.75 0.73 6.2 1.27 9.21 11.68 A-4 A-4 3.45 0.30 11.5 1.03 7.29 7.50 A-5 A-5 2.40 0.78 5.0 1.86 9.95 18.55 A-6 A-6 2.18 0.63 8.6 1.38 8.16 11.24 16.29 0.66 101.56 Off-site flows directed to Type R inlet along north frontage of W Stuart Street OS-1 OS-1 1.58 0.89 5.0 1.41 9.95 14.01 I (IN/HR) ∑ C*A 1.00 Q (CFS)TC ∑ C*A DIRECT RUNOFF Q (CFS) BASIN INFORMATON TOTAL RUNOFF REMARKSDESIGN POINT DRAIN BASIN AREA (AC)C100 TC K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Proposed Imperviousness and Runoff Coefficient Summary A-1 A-1 3.70 23%60.8%13.8%2.25 0.66 0.71 A-2 A-2 2.81 17%81.9%14.1%2.30 0.88 0.94 A-3 A-3 1.75 11%62.4%6.7%1.09 0.68 0.73 A-4 A-4 3.45 21%7.8%1.7%0.27 0.25 0.30 A-5 A-5 2.40 15%68.7%10.1%1.65 0.73 0.78 A-6 A-6 2.18 13%50.5%6.8%1.10 0.58 0.63 16.29 100%53.1%8.66 Off-site flows directed to Type R inlet along north frontage of W Stuart Street OS-1 OS-1 1.58 100%85.3%85.3%1.35 0.84 0.89 Impervious Area (Ac)C2 C100 DESIGN POINT DRAIN BASIN AREA (AC) % of Site (%) I (%) WEIGHTED (%) I (%) WEIGHTED (%) TOTAL Impervious Area (Ac)C2 C100 DESIGN POINT DRAIN BASIN AREA (AC) % of Site (%) K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\CIA Calculations.xls 096277019 Heritage Park Apartments Fort Collins, CO 7/13/2022 Prepared By: NAM Checked By: JPW Proposed Direct Runoff Summary Standard Rational Method A-1 A-1 3.70 6.99 26.23 A-2 A-2 2.81 7.03 26.36 A-3 A-3 1.75 3.37 11.68 A-4 A-4 3.45 1.75 7.50 A-5 A-5 2.40 4.97 18.55 A-6 A-6 2.18 2.89 11.24 16.29 27.00 101.56 Off-site flows directed to Type R inlet along north frontage of W Stuart Street OS-1 OS-1 1.58 3.77 14.01 Q100 (CFS) Q2 (CFS) DESIGN POINT DRAIN BASIN AREA (AC) DESIGN POINT DRAIN BASIN AREA (AC) Q2 (CFS) Q100 (CFS) K:\DEN_Civil\096277019_Heritage Park FoCO\_Project Files\Eng\Drainage\Apartments\Calculations\22-0707 Drainage Calc Updates - CM\CIA Calculations.xls 14 APPENDIX D Project: Basin ID: Depth Increment =ft Watershed Information Top of Micropool --0.00 ------6 0.000 Selected BMP Type =EDB 5014.9 --0.10 ------73 0.002 4 0.000 Watershed Area =10.19 acres --0.20 ------237 0.005 19 0.000 Watershed Length =926 ft --0.30 ------583 0.013 60 0.001 Watershed Length to Centroid =465 ft --0.40 ------1,022 0.023 141 0.003 Watershed Slope =0.050 ft/ft --0.50 ------1,710 0.039 277 0.006 Watershed Imperviousness =37.82%percent --0.60 ------2,686 0.062 497 0.011 Percentage Hydrologic Soil Group A =0.0%percent --0.70 ------3,809 0.087 822 0.019 Percentage Hydrologic Soil Group B =90.0%percent --0.80 ------5,220 0.120 1,273 0.029 Percentage Hydrologic Soil Groups C/D =10.0%percent --0.90 ------6,662 0.153 1,867 0.043 Target WQCV Drain Time =40.0 hours --1.00 ------7,842 0.180 2,592 0.060 Location for 1-hr Rainfall Depths = User Input --1.10 ------9,134 0.210 3,441 0.079 --1.20 ------10,098 0.232 4,403 0.101 --1.30 ------10,748 0.247 5,445 0.125 Optional User Overrides WQCV --1.40 ------11,293 0.259 6,547 0.150 Water Quality Capture Volume (WQCV) =0.148 acre-feet acre-feet --1.50 ------11,833 0.272 7,704 0.177 Excess Urban Runoff Volume (EURV) =0.398 acre-feet acre-feet --1.60 ------12,365 0.284 8,913 0.205 2-yr Runoff Volume (P1 = 0.82 in.) =0.213 acre-feet 0.82 inches --1.70 ------12,890 0.296 10,176 0.234 5-yr Runoff Volume (P1 = 1.09 in.) =0.314 acre-feet inches --1.80 ------13,407 0.308 11,491 0.264 10-yr Runoff Volume (P1 = 1.4 in.) =0.510 acre-feet 1.40 inches --1.90 ------13,917 0.320 12,857 0.295 25-yr Runoff Volume (P1 = 1.69 in.) =0.790 acre-feet inches --2.00 ------14,420 0.331 14,274 0.328 50-yr Runoff Volume (P1 = 1.99 in.) =1.028 acre-feet inches --2.10 ------14,918 0.342 15,741 0.361 100-yr Runoff Volume (P1 = 2.86 in.) =1.794 acre-feet 2.86 inches --2.20 ------15,411 0.354 17,257 0.396 500-yr Runoff Volume (P1 = 3.14 in.) =2.034 acre-feet inches --2.30 ------15,905 0.365 18,823 0.432 Approximate 2-yr Detention Volume =0.204 acre-feet --2.40 ------16,401 0.377 20,439 0.469 Approximate 5-yr Detention Volume =0.307 acre-feet --2.50 ------16,898 0.388 22,104 0.507 Approximate 10-yr Detention Volume =0.460 acre-feet --2.60 ------17,395 0.399 23,818 0.547 Approximate 25-yr Detention Volume =0.546 acre-feet --2.70 ------17,939 0.412 25,585 0.587 Approximate 50-yr Detention Volume =0.599 acre-feet --2.80 ------18,605 0.427 27,412 0.629 Approximate 100-yr Detention Volume =0.889 acre-feet --2.90 ------19,408 0.446 29,313 0.673 --3.00 ------20,380 0.468 31,302 0.719 Define Zones and Basin Geometry --3.10 ------21,519 0.494 33,397 0.767 Zone 1 Volume (WQCV) =0.148 acre-feet -------- Zone 2 Volume (100-year - Zone 1) =0.741 acre-feet -------- Select Zone 3 Storage Volume (Optional) =acre-feet -------- Total Detention Basin Volume =0.889 acre-feet -------- Initial Surcharge Volume (ISV) =user ft 3 -------- Initial Surcharge Depth (ISD) =user ft -------- Total Available Detention Depth (Htotal) =user ft -------- Depth of Trickle Channel (HTC) =user ft -------- Slope of Trickle Channel (STC) =user ft/ft -------- Slopes of Main Basin Sides (Smain) =user H:V -------- Basin Length-to-Width Ratio (RL/W) =user -------- -------- Initial Surcharge Area (AISV) =user ft 2 -------- Surcharge Volume Length (LISV) =user ft -------- Surcharge Volume Width (WISV) =user ft -------- Depth of Basin Floor (HFLOOR) =user ft -------- Length of Basin Floor (LFLOOR) =user ft -------- Width of Basin Floor (WFLOOR) =user ft -------- Area of Basin Floor (AFLOOR) =user ft 2 -------- Volume of Basin Floor (VFLOOR) =user ft 3 -------- Depth of Main Basin (HMAIN) =user ft -------- Length of Main Basin (LMAIN) =user ft -------- Width of Main Basin (WMAIN) =user ft -------- Area of Main Basin (AMAIN) =user ft 2 -------- Volume of Main Basin (VMAIN) =user ft 3 -------- Calculated Total Basin Volume (Vtotal) =user acre-feet -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- After providing required inputs above including 1-hour rainfall depths, click 'Run CUHP' to generate runoff hydrographs using the embedded Colorado Urban Hydrograph Procedure. Volume (ft 3) Volume (ac-ft) Area (acre) DETENTION BASIN STAGE-STORAGE TABLE BUILDER Optional Override Area (ft 2) Length (ft) Optional Override Stage (ft) Stage (ft) Stage - Storage Description Area (ft 2) Width (ft) Heritage Park Apartments Detention Pond Existing Condition MHFD-Detention, Version 4.05 (January 2022) ExampleZone Configuration (Retention Pond) EX MHFD-Detention_v4-05.xlsm, Basin 7/12/2022, 6:34 PM Project: Basin ID: Depth Increment =0.10 ft Watershed Information Top of Micropool --0.00 ------123 0.003 Selected BMP Type =EDB 5014 --0.10 ------430 0.010 28 0.001 Watershed Area =10.19 acres --0.20 ------873 0.020 93 0.002 Watershed Length =926 ft --0.30 ------1,478 0.034 210 0.005 Watershed Length to Centroid =465 ft --0.40 ------2,211 0.051 395 0.009 Watershed Slope =0.050 ft/ft --0.50 ------3,082 0.071 659 0.015 Watershed Imperviousness =50.63%percent --0.60 ------4,093 0.094 1,018 0.023 Percentage Hydrologic Soil Group A =0.0%percent --0.70 ------5,241 0.120 1,485 0.034 Percentage Hydrologic Soil Group B =90.0%percent --0.80 ------6,523 0.150 2,073 0.048 Percentage Hydrologic Soil Groups C/D =10.0%percent --0.90 ------7,881 0.181 2,793 0.064 Target WQCV Drain Time =40.0 hours --1.00 ------9,299 0.213 3,652 0.084 Location for 1-hr Rainfall Depths = User Input --1.10 ------10,866 0.249 4,660 0.107 --1.20 ------11,939 0.274 5,801 0.133 --1.30 ------12,810 0.294 7,038 0.162 Optional User Overrides WQCV --1.40 ------13,510 0.310 8,354 0.192 Water Quality Capture Volume (WQCV) =0.177 acre-feet acre-feet --1.50 ------14,014 0.322 9,730 0.223 Excess Urban Runoff Volume (EURV) =0.546 acre-feet acre-feet --1.60 ------14,328 0.329 11,147 0.256 2-yr Runoff Volume (P1 = 0.82 in.) =0.298 acre-feet 0.82 inches --1.70 ------14,524 0.333 12,590 0.289 5-yr Runoff Volume (P1 = 1.09 in.) =0.427 acre-feet inches --1.80 ------14,721 0.338 14,052 0.323 10-yr Runoff Volume (P1 = 1.4 in.) =0.638 acre-feet 1.40 inches --1.90 ------14,917 0.342 15,534 0.357 25-yr Runoff Volume (P1 = 1.69 in.) =0.910 acre-feet inches --2.00 ------15,112 0.347 17,036 0.391 50-yr Runoff Volume (P1 = 1.99 in.) =1.150 acre-feet inches --2.10 ------15,307 0.351 18,557 0.426 100-yr Runoff Volume (P1 = 2.86 in.) =1.906 acre-feet 2.86 inches --2.20 ------15,502 0.356 20,097 0.461 500-yr Runoff Volume (P1 = 3.14 in.) =2.146 acre-feet inches --2.30 ------15,698 0.360 21,657 0.497 Approximate 2-yr Detention Volume =0.288 acre-feet --2.40 ------15,894 0.365 23,237 0.533 Approximate 5-yr Detention Volume =0.420 acre-feet --2.50 ------16,091 0.369 24,836 0.570 Approximate 10-yr Detention Volume =0.602 acre-feet --2.60 ------16,291 0.374 26,455 0.607 Approximate 25-yr Detention Volume =0.695 acre-feet --2.70 ------16,491 0.379 28,094 0.645 Approximate 50-yr Detention Volume =0.759 acre-feet --2.80 ------16,690 0.383 29,753 0.683 Approximate 100-yr Detention Volume =1.088 acre-feet --2.90 ------16,889 0.388 31,432 0.722 --3.00 ------17,089 0.392 33,131 0.761 Define Zones and Basin Geometry --3.10 ------17,289 0.397 34,850 0.800 Select Zone 1 Storage Volume (Required) =acre-feet --3.20 ------17,488 0.401 36,589 0.840 Select Zone 2 Storage Volume (Optional) =acre-feet --3.30 ------17,689 0.406 38,348 0.880 Select Zone 3 Storage Volume (Optional) =acre-feet --3.40 ------17,890 0.411 40,127 0.921 Total Detention Basin Volume =acre-feet --3.50 ------18,093 0.415 41,926 0.962 Initial Surcharge Volume (ISV) =user ft 3 --3.60 ------18,295 0.420 43,745 1.004 Initial Surcharge Depth (ISD) =user ft --3.70 ------18,498 0.425 45,585 1.046 Total Available Detention Depth (Htotal) =user ft 100-YR WSEL --3.80 ------18,702 0.429 47,445 1.089 Depth of Trickle Channel (HTC) =user ft --3.90 ------18,905 0.434 49,325 1.132 Slope of Trickle Channel (STC) =user ft/ft --4.00 ------19,122 0.439 51,227 1.176 Slopes of Main Basin Sides (Smain) =user H:V --4.10 ------19,354 0.444 53,150 1.220 Basin Length-to-Width Ratio (RL/W) =user 5018.2 --4.20 ------19,619 0.450 55,099 1.265 -------- Initial Surcharge Area (AISV) =user ft 2 -------- Surcharge Volume Length (LISV) =user ft -------- Surcharge Volume Width (WISV) =user ft -------- Depth of Basin Floor (HFLOOR) =user ft -------- Length of Basin Floor (LFLOOR) =user ft -------- Width of Basin Floor (WFLOOR) =user ft -------- Area of Basin Floor (AFLOOR) =user ft 2 -------- Volume of Basin Floor (VFLOOR) =user ft 3 -------- Depth of Main Basin (HMAIN) =user ft -------- Length of Main Basin (LMAIN) =user ft -------- Width of Main Basin (WMAIN) =user ft -------- Area of Main Basin (AMAIN) =user ft 2 -------- Volume of Main Basin (VMAIN) =user ft 3 -------- Calculated Total Basin Volume (Vtotal) =user acre-feet -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- After providing required inputs above including 1-hour rainfall depths, click 'Run CUHP' to generate runoff hydrographs using the embedded Colorado Urban Hydrograph Procedure. Volume (ft 3) Volume (ac-ft) Area (acre) DETENTION BASIN STAGE-STORAGE TABLE BUILDER Optional Override Area (ft 2) Length (ft) Optional Override Stage (ft) Stage (ft) Stage - Storage Description Area (ft 2) Width (ft) Heritage Park Apartments Detention Pond MHFD-Detention, Version 4.05 (January 2022) ExampleZone Configuration (Retention Pond) MHFD-Detention_v4-05 -Proposed Condition .xlsm, Basin 7/12/2022, 6:36 PM Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK = Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =30.0 ft Gutter Width W =1.00 ft Street Transverse Slope SX =0.010 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.013 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =30.0 30.0 ft Warning 02 Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =10.3 10.3 inches Check boxes are not applicable in SUMP conditions Maximum Capacity for 1/2 Street based On Allowable Spread Minor Storm Major Storm Water Depth without Gutter Depression (Eq. ST-2)y =3.60 3.60 inches Vertical Depth between Gutter Lip and Gutter Flowline (usually 2")dC =1.0 1.0 inches Gutter Depression (dC - (W * Sx * 12))a =0.88 0.88 inches Water Depth at Gutter Flowline d =4.48 4.48 inches Allowable Spread for Discharge outside the Gutter Section W (T - W)TX =29.0 29.0 ft Gutter Flow to Design Flow Ratio by FHWA HEC-22 method (Eq. ST-7)EO =0.103 0.103 Discharge outside the Gutter Section W, carried in Section TX QX =0.0 0.0 cfs Discharge within the Gutter Section W (QT - QX)QW =0.0 0.0 cfs Discharge Behind the Curb (e.g., sidewalk, driveways, & lawns)QBACK =0.0 0.0 cfs Maximum Flow Based On Allowable Spread QT =SUMP SUMP cfs Flow Velocity within the Gutter Section V =0.0 0.0 fps V*d Product: Flow Velocity times Gutter Flowline Depth V*d =0.0 0.0 Maximum Capacity for 1/2 Street based on Allowable Depth Minor Storm Major Storm Theoretical Water Spread TTH =78.7 78.7 ft Theoretical Spread for Discharge outside the Gutter Section W (T - W)TX TH =77.7 77.7 ft Gutter Flow to Design Flow Ratio by FHWA HEC-22 method (Eq. ST-7)EO =0.036 0.036 Theoretical Discharge outside the Gutter Section W, carried in Section TX TH QX TH =0.0 0.0 cfs Actual Discharge outside the Gutter Section W, (limited by distance TCROWN)QX =0.0 0.0 cfs Discharge within the Gutter Section W (Qd - QX)QW =0.0 0.0 cfs Discharge Behind the Curb (e.g., sidewalk, driveways, & lawns)QBACK =0.0 0.0 cfs Total Discharge for Major & Minor Storm (Pre-Safety Factor)Q =0.0 0.0 cfs Average Flow Velocity Within the Gutter Section V =0.0 0.0 fps V*d Product: Flow Velocity Times Gutter Flowline Depth V*d =0.0 0.0 Slope-Based Depth Safety Reduction Factor for Major & Minor (d > 6") Storm R =SUMP SUMP Max Flow Based on Allowable Depth (Safety Factor Applied)Qd =SUMP SUMP cfs Resultant Flow Depth at Gutter Flowline (Safety Factor Applied)d =inches Resultant Flow Depth at Street Crown (Safety Factor Applied)dCROWN =inches MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.01 (April 2021) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Heritage Park Apartments Inlet A-1 MHFD-Inlet_v5.01 (2).xlsm, Inlet A-1 7/12/2022, 6:40 PM Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =4 4 Water Depth at Flowline (outside of local depression)Ponding Depth =10.3 10.3 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Area Opening Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =1.00 1.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.78 0.78 ft Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =0.97 0.97 Curb Opening Performance Reduction Factor for Long Inlets RFCurb =0.98 0.98 Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =48.9 48.9 cfs Inlet Capacity IS GOOD for Minor and Major Storms(>Q PEAK)Q PEAK REQUIRED =10.8 40.2 cfs CDOT Type R Curb Opening INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.01 (April 2021) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Openi Override MHFD-Inlet_v5.01 (2).xlsm, Inlet A-1 7/12/2022, 6:40 PM Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK = Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =30.6 ft Gutter Width W =1.00 ft Street Transverse Slope SX =0.034 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.013 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =30.6 30.6 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.01 (April 2021) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Heritage Park Apartments Inlet A-2 MHFD-Inlet_v5.01 (2).xlsm, Inlet A-2 7/12/2022, 6:40 PM Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =1 1 Water Depth at Flowline (outside of local depression)Ponding Depth =6.0 6.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Area Opening Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =1.00 1.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.42 0.42 ft Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =0.77 0.77 Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =5.9 5.9 cfs WARNING: Inlet Capacity less than Q Peak for Minor and Major Storms Q PEAK REQUIRED =7.0 26.4 cfs CDOT Type R Curb Opening INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.01 (April 2021) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Opening Override Depths MHFD-Inlet_v5.01 (2).xlsm, Inlet A-2 7/12/2022, 6:40 PM Project: Inlet ID: Gutter Geometry: Maximum Allowable Width for Spread Behind Curb TBACK =ft Side Slope Behind Curb (leave blank for no conveyance credit behind curb)SBACK =ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020)nBACK = Height of Curb at Gutter Flow Line HCURB =6.00 inches Distance from Curb Face to Street Crown TCROWN =36.0 ft Gutter Width W =1.00 ft Street Transverse Slope SX =0.020 ft/ft Gutter Cross Slope (typically 2 inches over 24 inches or 0.083 ft/ft)SW =0.083 ft/ft Street Longitudinal Slope - Enter 0 for sump condition SO =0.000 ft/ft Manning's Roughness for Street Section (typically between 0.012 and 0.020)nSTREET =0.013 Minor Storm Major Storm Max. Allowable Spread for Minor & Major Storm TMAX =36.0 36.0 ft Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX =6.0 6.0 inches Check boxes are not applicable in SUMP conditions MINOR STORM Allowable Capacity is based on Depth Criterion Minor Storm Major Storm MAJOR STORM Allowable Capacity is based on Depth Criterion Qallow =SUMP SUMP cfs MHFD-Inlet, Version 5.01 (April 2021) ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread) Heritage Park Apartments Inlet A-5 MHFD-Inlet_v5.01 (2).xlsm, Inlet A-5 7/12/2022, 6:40 PM Design Information (Input)MINOR MAJOR Type of Inlet Type = Local Depression (additional to continuous gutter depression 'a' from above)alocal =3.00 3.00 inches Number of Unit Inlets (Grate or Curb Opening)No =2 2 Water Depth at Flowline (outside of local depression)Ponding Depth =12.0 12.0 inches Grate Information MINOR MAJOR Length of a Unit Grate Lo (G) =N/A N/A feet Width of a Unit Grate Wo =N/A N/A feet Area Opening Ratio for a Grate (typical values 0.15-0.90)Aratio =N/A N/A Clogging Factor for a Single Grate (typical value 0.50 - 0.70)Cf (G) =N/A N/A Grate Weir Coefficient (typical value 2.15 - 3.60)Cw (G) =N/A N/A Grate Orifice Coefficient (typical value 0.60 - 0.80)Co (G) =N/A N/A Curb Opening Information MINOR MAJOR Length of a Unit Curb Opening Lo (C) =5.00 5.00 feet Height of Vertical Curb Opening in Inches Hvert =6.00 6.00 inches Height of Curb Orifice Throat in Inches Hthroat =6.00 6.00 inches Angle of Throat (see USDCM Figure ST-5)Theta =63.40 63.40 degrees Side Width for Depression Pan (typically the gutter width of 2 feet)Wp =1.00 1.00 feet Clogging Factor for a Single Curb Opening (typical value 0.10)Cf (C) =0.10 0.10 Curb Opening Weir Coefficient (typical value 2.3-3.7)Cw (C) =3.60 3.60 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70)Co (C) =0.67 0.67 Low Head Performance Reduction (Calculated)MINOR MAJOR Depth for Grate Midwidth dGrate =N/A N/A ft Depth for Curb Opening Weir Equation dCurb =0.92 0.92 ft Combination Inlet Performance Reduction Factor for Long Inlets RFCombination =1.00 1.00 Curb Opening Performance Reduction Factor for Long Inlets RFCurb =1.00 1.00 Grated Inlet Performance Reduction Factor for Long Inlets RFGrate =N/A N/A MINOR MAJOR Total Inlet Interception Capacity (assumes clogged condition)Qa =25.5 25.5 cfs Inlet Capacity IS GOOD for Minor and Major Storms(>Q PEAK)Q PEAK REQUIRED =5.0 18.6 cfs CDOT Type R Curb Opening INLET IN A SUMP OR SAG LOCATION MHFD-Inlet, Version 5.01 (April 2021) H-VertH-Curb W Lo (C) Lo (G) Wo WP CDOT Type R Curb Opening Override Depths MHFD-Inlet_v5.01 (2).xlsm, Inlet A-5 7/12/2022, 6:40 PM Sheet 1 of 1 Designer: Company: Date: Project: Location: 1. Design Discharge for 2-Year Return Period Q2 =1.48 cfs 2. Hydraulic Residence Time A) : Length of Grass Swale LS =128.4 ft B) Calculated Residence Time (based on design velocity below)THR=8.7 minutes 3. Longitudinal Slope (vertical distance per unit horizontal) A) Available Slope (based on site constraints)Savail =0.005 ft / ft B) Design Slope SD =0.005 ft / ft 4. Swale Geometry A) Channel Side Slopes (Z = 4 min., horiz. distance per unit vertical)Z =15.00 ft / ft B) Bottom Width of Swale (enter 0 for triangular section)WB =2.00 ft 5. Vegetation A) Type of Planting (seed vs. sod, affects vegetal retardance factor) 6. Design Velocity (0.428 ft / s maximum for desirable 5-minute residence time)V2 =0.25 ft / s 7. Design Flow Depth (1 foot maximum) D2 =0.57 ft A) Flow Area A2 =6.0 sq ft B) Top Width of Swale W T =19.1 ft C) Froude Number (0.50 maximum)F =0.08 D) Hydraulic Radius RH =0.31 E) Velocity-Hydraulic Radius Product for Vegetal Retardance VR =0.08 F) Manning's n (based on SCS vegetal retardance curve D for sodded grass)n =0.200 G) Cumulative Height of Grade Control Structures Required HD =0.00 ft AN UNDERDRAIN IS 8. Underdrain REQUIRED IF THE (Is an underdrain necessary?)DESIGN SLOPE < 2.0% 9. Soil Preparation (Describe soil amendment) 10. Irrigation Notes: washed sands, 30% top soil , 5% leaf compost, and 5% mulch), bedding course and slotted underdrain, and separation liner Linear bioretention designed per Section 6.5 (Linear Bioretention - Low Impact Development) of Chapter 7 of the Fort Collins Stormwater Criteria Manual (Water Quality). Soil section below linear bioretention to include mulch, bioretention media per Appendix C of the LID Implementation Manual (60% Design Procedure Form: Grass Swale (GS) James Waller Kimley-Horn July 11, 2022 Heritage Park Apartments Major Amendment Fort Collins, CO UD-BMP (Version 3.07, March 2018) Choose One Temporary Permanent Choose One Grass From Seed Grass From Sod Choose One YES NO UD-BMP_v3.07 (6).xlsm, GS 7/11/2022, 8:57 AM A-1 Pipe Project Description Manning FormulaFriction Method Normal DepthSolve For Input Data 0.013Roughness Coefficient ft/ft0.007Channel Slope in30.0Diameter cfs31.74Discharge Results in22.8Normal Depth ft²4.0Flow Area ft5.3Wetted Perimeter in9.1Hydraulic Radius ft2.14Top Width in23.0Critical Depth %75.9Percent Full ft/ft0.007Critical Slope ft/s7.94Velocity ft0.98Velocity Head ft2.88Specific Energy 1.023Froude Number cfs36.91Maximum Discharge cfs34.32Discharge Full ft/ft0.006Slope Full SupercriticalFlow Type GVF Input Data in0.0Downstream Depth ft0.0Length 0Number Of Steps GVF Output Data in0.0Upstream Depth N/AProfile Description ft0.00Profile Headloss %0.0Average End Depth Over Rise %75.9Normal Depth Over Rise ft/sInfinityDownstream Velocity ft/sInfinityUpstream Velocity in22.8Normal Depth in23.0Critical Depth ft/ft0.007Channel Slope ft/ft0.007Critical Slope Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 7/11/2022 FlowMaster [10.03.00.03] Bentley Systems, Inc. Haestad Methods Solution CenterHP Apartments.fm8 A-5 Pipe Project Description Manning FormulaFriction Method Normal DepthSolve For Input Data 0.013Roughness Coefficient ft/ft0.015Channel Slope in15.0Diameter cfs4.97Discharge Results in8.6Normal Depth ft²0.7Flow Area ft2.1Wetted Perimeter in4.1Hydraulic Radius ft1.24Top Width in10.9Critical Depth %57.2Percent Full ft/ft0.008Critical Slope ft/s6.84Velocity ft0.73Velocity Head ft1.44Specific Energy 1.575Froude Number cfs8.57Maximum Discharge cfs7.96Discharge Full ft/ft0.006Slope Full SupercriticalFlow Type GVF Input Data in0.0Downstream Depth ft0.0Length 0Number Of Steps GVF Output Data in0.0Upstream Depth N/AProfile Description ft0.00Profile Headloss %0.0Average End Depth Over Rise %57.2Normal Depth Over Rise ft/sInfinityDownstream Velocity ft/sInfinityUpstream Velocity in8.6Normal Depth in10.9Critical Depth ft/ft0.015Channel Slope ft/ft0.008Critical Slope Page 1 of 127 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 7/11/2022 FlowMaster [10.03.00.03] Bentley Systems, Inc. Haestad Methods Solution CenterHP Apartments.fm8 15 APPENDIX E 3.4 Bioretention Bioretention areas (often called Rain Gardens) are depressed landscape features that are designed to collect and treat stormwater. These areas can be linear or free form depending on the site context. Bioretention areas primarily treat stormwater by filtering sediment as the water travels downward through the soil, but it is also a living system where plants and micro-organisms maintain the soil structure and break down dissolved pollutants. COST AND BENEFIT CONSIDERATIONS MAINTENANCE CONSIDERATIONS • May be used to meet landscape requirements. • Accept concentrated flow sources. • Flexibility in size and shape (linear or basin) make this a popular BMP. • Can be combined with underground infiltration BMPs for maximizing performance in a small footprint. • In dry weather bioretention can serve other uses such as open space. • Sometimes used to buffer pedestrian and cyclists from roadways. • Easier to observe and access for maintenance than underground BMPs. • Smaller cells may require more frequent maintenance and sediment removal. • Consider maintenance practices when specifying mulchs. Floatable materials are not allowed. • BMPs that are used for snow storage or receive flow from sanded areas require more frequent sediment removal. • Size forebay accordingly to maintenance frequency and adjacent context. • When adjacent to parking and sidewalks provide a flat level step out zone for pedestrian comfort next to the graded slope or wall. • Group plantings of similar needs or type to simplify maintenance. • Choose plants to fit conditions e.g. low plants along parking. • Keep inlets clear of vegetation.Presettling forebay example at Library Park Section Three: LID BMP Fact Sheet 3.5City of Fort Collins | LID Implementation ManualPrecedent Projects • North College Market Place • Woodward Commercial Development • Plan and delineate bioretention areas prior to site disturbance to protect subgrade from construction-related compaction. • Plants will likely require permanent irrigation. • Protect finished BMPs from construction sediment, including during landscape installation. • During establishment protect BMPs from washout. • Avoid geotextile wrapping of underdrain pipes. • Provide adequately-sized and armored- overflow for high flow conditions. • Ensure that rock and plant material placed near inlets do not block flow. CONSTRUCTION CONSIDERATIONS DESIGN CONSIDERATIONS • For concentrated flow applications, armor inlets against scour. • Scale the depth of drop from walking areas to the top of bioretention according to the site use and aesthetics, generally <18”. • Check dams provide ponding depth and slow velocities for linear bioretention. • Consider size, location and material of inlet pipes and overflow structures and how they affect aesthetics and impact to impervious area footprint. • In the right-of-way, street tree requirements must be met. Trees are to be located outside of bioretention and positioned adequate distance from curb and sidewalk. Consider placing bioretention between street trees. • Use landscape areas / islands to encourage multiple uses of space. • Use plantings that are appropriate for the site. Native plants are encouraged. • Public right-of-way may not be used to meet LID requirements for private property development. • Developer-installed bioretention areas shall be maintained by the developer. • For public projects maintenance responsibility shall be determined during the design phase. Notes and References • UDFCD Treatment BMP Fact Sheet T-03 • Soil Media Specification (Appendix C) • LCUASS Appendix A - Standard Drawings * This is a graphic representation. For more technical guidance, refer to the construction detail. 5.6 Soil mixes for bioretention areas and tree filters are specially engineered to support plant growth while promoting infiltration. The following mixes shall be used for projects in the public right-of-way: Fort Collins Bioretention/Rain Garden Soil Mix • Washed Sand: 60% • Top Soil: 30% • Leaf / Yardpride Compost: 5% • Mulch: 5% For full specifications see: https://www.fcgov.com/utilities/business/builders-and-developers/development-forms-guidelines-regulations Fort Collins Tree Filter Soil Mix • Glacier Rock Sand: 55% • Top Soil: 30% • Ground Mulch: 5% • Yard Pride Compost: 10% Appendix C: Soil Mixes The following plant lists shall be consulted for every project. Fort Collins Streetscape Standards https://www.fcgov.com/planning/streetscapedesign.php Provides planting and layout standards for streetscapes and rights-of-way within Fort Collins. State of Colorado Noxious Weeds List https://www.colorado.gov/pacific/sites/default/files/NoxiousWeedList.pdf State-wide list of List A, B and C noxious weeds, with images and key points for identification, maintained by the Colorado Department of Agriculture. Website also provides weed maps, eradication suggestions and Weed Watch List. Fort Collins Native Plants http://www.fcgov.com/naturalareas/pdf/nativeplants2013.pdf Fort Collins Plant List for Development https://www.fcgov.com/forestry/plant_list.pdf Fort Collins Native Seed Mixes https://www.fcgov.com/developmentreview/pdf/seed-mixes.pdf?1516225380 Appendix D: Plant Lists FORT COLLINS STORMWATER CRITERIA MANUAL Water Quality (Ch. 7) 6.0 Low Impact Development 6.0 Low Impact Development Page 18 Figure 6.4-1. Design Criteria for Rain Gardens and Sand Filters 6.5 Linear Bioretention Linear bioretention has low longitudinal slopes and broad cross-sections that convey flow in a slow and shallow manner, thereby facilitating sedimentation and filtering (straining) while limiting erosion. Berms or check dams may be incorporated into the facility to reduce velocities and encourage settling and infiltration. When using berms, an underdrain system should be provided. Linear bioretention is an integral part of the LID concept and may be used as an alternative to a curb and gutter system. Design and construction detailing for linear bioretention systems are presented in the LID Implementation Manual in Appendix C. Included below are some additional design parameters that are specific to the City of Fort Collins. Figure 6.5-1. Design Criteria for Linear Bioretention LOCATION •Generally, Rain Gardens and Sand Filters shall be placed "offline" from the detention basin VOLUME •Rain Gardens and Sand Filters are sized for the WQCV •Forebay shall be included and is to be sized for 1% of the WQCV and have a minimum depth of 12" •UD-BMP workbook may be utilized for sizing •Maximum depth is 12" for Rain Gardens OVERFLOW •Area inlet or overflow required at the WQCV depth (12" above the rain garden finished grade surface) UNDERDRAINS •Underdrain piping is required •Underdrain cleanouts are required for flushing and inspection SLOPES •Minimum longitudinal slope is 0.5% •Maximum longitudinal slope is 1.0% GEOMETRY •Minimum bottom width is 24" •Maximum side slopes 4:1 2-YR STORM DESIGN •Froude No. ≤ 0.5 •Velocity ≤ 1 fps •Depth ≤ 12"