Project_4_-_Parfet_Street_-_Drainage_Memo.pdf

PDF 4 MB Posted Aug 14, 2026

Attached to: Sidewalk Gap Construction
Solicitation number: 26-44
Issued by: Jefferson County, Weston CDP, Colorado

About this file

Written by GovTribe AI · Aug 18, 2026

This is a drainage design memorandum prepared by Olsson for the City of Wheat Ridge, Colorado, detailing the hydrological and hydraulic engineering analysis for Project 4 of the Sidewalk Gap Improvements Program. The project involves constructing sidewalk improvements along Parfet Street from 35th Avenue to 3550 Parfet Street and along the north side of 35th Avenue, including the addition of curb and gutter, roadway patching, and new storm infrastructure. The design encompasses approximately 4 acres across three drainage basins (4.01, 4.02, and 4.03) that tie into the existing storm network, which ultimately drains to Lena Gulch via Rolling Hills Tributary. The project does not require the relocation of existing infrastructure and is designed to meet City of Wheat Ridge and Mile High Flood District (MHFD) drainage criteria for both minor (5-year) and major (100-year) storm events. Peak flow calculations indicate total flows of 5.01 cfs for the 5-year storm and 16.66 cfs for the 100-year storm across all basins.

The proposed design includes two double Wheat Ridge combination inlets and one Nyloplast dome grate inlet strategically positioned to manage runoff while maintaining street capacity criteria limiting minor storm depth to 6 inches and major storm depth to 12 inches. Storm drain pipes ranging from 12 to 18 inches in diameter convey flows to existing infrastructure, with capacity calculations confirming adequate inlet performance under clogged conditions. The project disturbs less than one acre and increases imperviousness by only 1.2 percent, which exempts it from detention and water quality treatment requirements under the City's MS4 permit. No variances from design criteria are requested. The drainage design assumes existing downstream infrastructure has adequate capacity, though the project scope does not include analysis of the entire downstream storm system. Detailed hydrological calculations utilizing the MHFD Rational Method, NOAA Atlas 14 precipitation data, and NRCS soil survey information are provided in the appendices.

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CITY OF WHEAT RIDGE

PROJECT 4 -PARFET ST,

35TH AVE TO 3550

PARFET ST

SIDEWALK GAP PROGRAM

Prepared for:

City of Wheat Ridge Colorado

Wheat Ridge, Colorado

Prepared by:

Olsson

1525 Raleigh Street, Suite 400

Denver, CO 80204

May 2026

Olsson Project No. B25-03001

Project 4 - Parfet St, 35th Ave to 3550 Parfet Sidewalk Gap Program

City of Wheat Ridge Project No. 025-029B May 2026

B25-03001 1

TABLE OF CONTENTS

1. Introduction

1.1 Project Location and Purpose

1.2 Description of Property

1.2.1 Ground Cover and Topography

1.2.2 Soils Description

1.2.3 Major Drainageways

2. Hydrology

2.1 Drainage Basin Map

2.2 Major Basin Description

2.3 On-Site Description

2.4 Precipitation Data

2.5 Design Flood Frequency

3. Existing Structures

4. Design Discussion

5. Recommended Design

5.1 Inlets

5.2 Storm Drain

5.3 Detention/Water Quality

6. Variances

References

Appendix A Hydrology

Appendix B Hydraulics

Appendix C Reference Information

B25-03001 2

1. INTRODUCTION

Project 4, Parfet Street from 35th Avenue to 3550 Parfet Street, includes adding a sidewalk along the north side of West 35th Avenue and east side of Parfet Street. Additionally, the project will include curb and gutter, roadway patching, and new storm infrastructure. The project ties into the existing storm network and relocation of existing infrastructure is not proposed. This project is designed for the City of Wheat Ridge as part of the Sidewalk Gaps Program.

1.1 Project Location and Purpose

Project 4 will improve pedestrian connectivity by extending the eastern sidewalk along Parfet

Street from West 35th Avenue to the northern edge of the 3550 Parfet Street property and adding a sidewalk connection along the northern edge of West 35th Avenue from Parfet Street to the eastern edge of the 3500 Parfet Street property. This project is located within a residential area in the City of Wheat Ridge, Colorado. A vicinity map is shown in Figure 1.

Figure 1 - Site Vicinity Map

PROJECT AREA

END PROJECT

104+37.15

BEGIN PROJECT

100+56.40

35TH AVE

32ND AVE

38TH AVE

S T

B25-03001 3

1.2 Description of Property

1.2.1 Ground Cover and Topography

The improvements include adding sidewalk, curb and gutter, inlets, storm pipe, a depressed area, and driveways on the north and east sides of West 35th Avenue and Parfet Street, respectfully. The project area is fully developed and ground cover is comprised of pavement, grass, gravel, and bare earth.

Under existing conditions, the north side of West 35th Avenue drains west to the corner of Parfet

Street and West 35th Avenue. Currently, the east side of Parfet Street drains south to the corner of Parfet Street and West 35th Avenue. The flows from West 35th Avenue and Parfet Street meet at the northeast corner of the intersection and are conveyed south through a small drain into an existing box culvert. Flows from the project area eventually outfall into Lena Gulch.

1.2.2 Soils Description

The project area includes Hydrologic Soil Group Types C and B which are characterized as having moderate infiltration rates and runoff potentials. According to the United States

Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS), the soils in the project area are comprised of 0.8 acres of Nunn-Urban land complex, 2.5 acres of Denver-

Kutch-Urban land complex, and 0.7 acres of Haverson loam. The full soils report is included in

Appendix C.

1.2.3 Major Drainageways

There are no major drainageways within the project area. The entire project drains to Lena

Gulch via street conveyance, storm infrastructure, and tributary swales.

2. HYDROLOGY

2.1 Drainage Basin Map

Drainage basins were delineated using survey information, supplemented with 2020 LiDAR data outside of the project area. The Rational Method was used to complete hydrological calculations using the MHFD rational spreadsheet. A drainage map of the proposed conditions is included in

Appendix A.

2.2 Major Basin Description

There are no major cross-drainage waterways that pass through the project area, and no major offsite basin delineation was required for the project. The project site flows directly to Lena

Gulch.

B25-03001 4

2.3 On-Site Description

Three basins were delineated under proposed conditions.

4.01 - This basin delineates flow contributing to a proposed double Wheat Ridge combination inlet located along West 35th Avenue. Flow is conveyed from the double Wheat Ridge combination inlet via a proposed storm pipe that connects to an existing inlet that discharges to

Rolling Hills Tributary, a tributary to Lena Gulch.

4.02 - This basin delineates flow contributing to a proposed Wheat Ridge combination inlet located along Parfet Street. Flow is conveyed from the Wheat Ridge combination inlet via a proposed storm pipe that connects directly to an existing 4-foot by 8-foot box culvert crossing under Parfet Street. The existing box culvert crossing discharges to Rolling Hills Tributary, a tributary to Lena Gulch.

4.03 - This basin delineates flow contributing to a proposed Nyloplast inlet behind the proposed curb ramp at the corner of Parfet Street and West 35th Avenue. Flow is conveyed via a proposed storm pipe that is connected to the proposed inlet in basin 4.02.

Table 1 - Peak Flow Summary

Basin 5-year Flows (cfs) 100-year Flows (cfs)

4.01 3.89 12.58

4.02 0.53 1.62

4.03 0.59 2.46

TOTAL 5.01 16.66

2.4 Precipitation Data

The project is located in the City of Wheat Ridge; therefore, the City of Wheat Ridge drainage design criteria was applied and supplemented with Mile High Flood District (MHFD) Criteria as required. Precipitation data was determined in accordance with the MHFD guidance using the point precipitation frequency estimates from NOAA Atlas 14, Volume 8, Version 2 for Wheat

Ridge, Colorado at the project location. Precipitation data is included in Appendix A.

2.5 Design Flood Frequency

The Jefferson County criteria was referenced to determine a minor and major flood frequency of

5-years and 100-years, respectively. MHFD Criteria and Jefferson County criteria were referenced to determine the allowable overtopping and street capacity for local streets. The more stringent of the two criterion, MHFD criteria, was used. Figure 2 and Figure 3 show the

MHFD street capacity criteria used for this project.

B25-03001 5

For this project, the minor storm flow may spread to the crown of the street and must not exceed

6-inches in depth as to not overtop the curb. The major storm flow may spread to the crown of the street and must not exceed 12-inches in depth.

Figure 2 - MHFD Minor Storm Street Capacity Criteria

Figure 3 - MHFD Major Storm Street Capacity Criteria

B25-03001 6

3. EXISTING STRUCTURES

There is an existing inlet at the corner of West 35th Avenue and Parfet Street that conveys flow south to Rolling Hills Tributary, a tributary to Lena Gulch. An existing 4-foot by 8-foot box culvert is located south of the project area and conveys on-site flows west under Parfet Street.

4. DESIGN DISCUSSION

The proposed drainage does not change the existing drainage patterns and ties into the current drainage infrastructure. All inlets meet the City of Wheat Ridge and MHFD spread design criteria. Existing conditions were not evaluated and it is assumed that the existing downstream infrastructure has capacity for the design flows.

This project does not disturb more than one acre and therefore does not require water quality treatment per the City’s MS4 permit.

5. RECOMMENDED DESIGN

5.1 Inlets

The street inlets were analyzed to meet the spread criteria as discussed in Section 2.5.

Calculations were completed using the MHFD-Inlet, Version 6.00 spreadsheet. For the inlet at basin 4.02, the street capacity was evaluated at the full section as well as the reduced section of road since the roadway tapers just north of the corner of Parfet Street and West 35th Avenue.

The full roadway section is 34 feet wide, and the reduced roadway section is 28 feet wide. The

Nyloplast inlet was sized using the online Nyloplast Grate Inlet Calculator and inlet capacity charts. The flow from basin 4.03 will be accumulated in a depressed area behind the proposed sidewalk and collected by the Nyloplast inlet. Full calculations are included in Appendix B.

5.2 Storm Drain

It is assumed that the existing downstream storm drain has capacity for the flows captured by the proposed inlets. Analysis of the entire downstream storm system is not included in the scope of this project. To determine the proposed pipe size from the inlet at basin 4.01, the downstream inlet and swale were assumed to be empty. To determine the size of the storm pipe conveying flow from basins 4.02 and 4.03, the downstream culvert was assumed to be full. Full calculations for this evaluation are included in Appendix B.

B25-03001 7

5.3 Detention/Water Quality

This project is not required to provide detention. The increase in percent imperviousness compared to existing conditions is 1.2%, which will produce minimally increased runoff.

The project disturbs less than one acre; therefore, no water quality is required.

6. VARIANCES

No variances from the criteria are requested with this project.

REFERENCES

Mile High Flood District. April 2025. MHFD-Culvert Workbook, Version 4.01.

Mile High Flood District. August 2025. MHFD-Inlet Workbook, Version 6.00.

Mile High Flood District. August 2025. MHFD-Rational Workbook, Version 3.00.

National Oceanic and Atmospheric Administration. 2026. NOAA Atlas 14, Volume 8, Version 2.

United States Department of Agriculture. 2026. Custom Soil Resource Report for

Golden Area, Colorado, Parts of Denver, Douglas, Jefferson, and Park Counties.

Urban Drainage and Flood Control District, Volume 1. March 2024. Urban Storm

Drainage Criteria Manual: Volume 1.

Urban Drainage and Flood Control District, Volume 2. January 2016. Urban Storm

Drainage Criteria Manual: Volume 2.

APPENDIX A

HYDROLOGY

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BARRIER AHEAD

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1525 Raleigh Street Suite 400 Denver, CO 80204 olsson.com

TEL 303.237.2072

DATE:

DRAWN BY:

PROJECT NO:

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B25-03001

05.19.2026

1PROPOSED DRAINAGE MAP

EXHIBIT

A = BASIN DESCRIPTION

B = AREA (AC)

C = COMPOSITE RUNOFF COEFFICIENTS

(5-YR, 100-YR)

D = DESIGN POINT

FLOW PATH

LEGEND

BASIN BOUNDARY

PROPOSED STORM

EXISTING MAJOR CONTOUR

(SURVEY)

EXISTING MINOR CONTOUR

(SURVEY)

EXISTING MAJOR CONTOUR

(LIDAR)

EXISTING MINOR CONTOUR

(LIDAR)

PROPOSED MAJOR CONTOURS

PROPOSED MINOR CONTOURS

CHANNELIZED FLOW

OVERLAND FLOW

0.462.91

4.01

0.70

0.500.35

4.02

0.72

0.320.70

4.03

0.62

4.034.02

4.01

90' 180'45'0'

SCALE IN FEET

XXXX

WEST 35TH AVE

Designer:

Company:

Date:

Project:

Location:

Provide subcatchment names on the Rational Calcs worksheet to open up the table below.

Imperviousness

Source

Imperviousness

Category Calculated

Imperviousness

(Optional)

Override

Imperviousness

WQE

2-yr

5-yr 10-yr 25-yr 50-yr 100-yr 500-yr

WQE

2-yr

5-yr 10-yr 25-yr 50-yr 100-yr 500-yr Comments

4.01 2 2.91 B,C/D 95.0% 52.5% 0.40 0.46 0.51 0.61 0.65 0.70 0.75 0.40 0.46 0.51 0.61 0.65 0.70 0.75

0.34 B Surface Type Roadways and Paved Streets 95% 57% 0.43 0.46 0.52 0.61 0.65 0.69 0.74

2.57 C/D Surface Type Roadways and Paved Streets 95% 52% 0.40 0.46 0.51 0.61 0.65 0.70 0.75

4.02 2 0.35 B,C/D 95.0% 57.3% 0.45 0.50 0.55 0.64 0.67 0.72 0.77 0.45 0.50 0.55 0.64 0.67 0.72 0.77

0.09 B Surface Type Roadways and Paved Streets 95% 83% 0.67 0.70 0.72 0.77 0.79 0.81 0.84

0.26 C/D Surface Type Roadways and Paved Streets 95% 48% 0.37 0.43 0.49 0.59 0.63 0.68 0.74

4.03 2 0.70 B,C/D 95.0% 37.0% 0.27 0.32 0.39 0.51 0.56 0.62 0.69 0.27 0.32 0.39 0.51 0.56 0.62 0.69

0.25 B Surface Type Roadways and Paved Streets 95% 34% 0.24 0.26 0.33 0.46 0.52 0.58 0.66

0.45 C/D Surface Type Roadways and Paved Streets 95% 39% 0.29 0.35 0.42 0.54 0.58 0.64 0.71

Determination of Runoff Coefficients for Rational Method MHFD-Rational, Version 3.00 (August 2025)

Sidewalk Gaps - Project 04 Cells of this color are for required user-input

Cells of this color are for optional override values

Subcatchment

Name

# of

Subareas

Area

(ac)

NRCS

Hydrologic

Soil Group

(Optional) Override Runoff Coefficient, C

Wheat Ridge

Runoff Coefficient, C

Madison Stewart Olsson 5/11/2026

Percent Imperviousness

Project 04 _MHFD-Rational v3.xlsm, Runoff Coeffs 5/11/2026, 17:10

Designer:

Company:

Date:

Project:

Location:

Subcatchment

Name

4.01

4.02

4.03

Select MHFD location for NOAA Atlas 14 Rainfall Depths from the pulldown list OR enter your own depths obtained from the NOAA website (click this link)

WQE 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 500-yr

1-hour rainfall depth, P1 (in) = 0.61 0.77 1.04 1.28 1.64 1.92 2.22 2.99 a b c

Rainfall Intensity Equation Coefficients = 28.50 10.00 0.786

Overland Flow

Length

Li (ft)

U/S Elevation

(ft)

(Optional)

D/S Elevation

(ft)

(Optional)

Overland Flow

Slope

Si (ft/ft)

Overland Flow

Time ti (min)

Channelized

Flow Length

Lt (ft)

U/S Elevation

(ft)

(Optional)

D/S Elevation

(ft)

(Optional)

Channelized

Flow Slope

St (ft/ft)

NRCS

Conveyance

Factor K

Channelized

Flow Velocity

Vt (ft/sec)

Channelized

Flow Time tt (min)

Computed tc

(min)

Regional tc

(min)

Selected tc

(min)

(Optional)

Override tc

(min)

WQE 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 500-yr WQE 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 500-yr

93.90 5450.50 5441.00 0.101 5.23 664.18 5441.00 5427.77 0.020 20 2.82 3.92 9.15 21.88 9.15 1.71 2.15 2.91 3.58 4.59 5.37 6.21 8.37 2.00 2.52 3.89 5.36 8.14 10.15 12.58 18.28

118.77 5439.00 5432.96 0.051 6.92 224.05 5432.96 5427.65 0.024 20 3.08 1.21 8.13 17.69 8.13 1.78 2.24 3.04 3.74 4.79 5.61 6.49 8.74 0.28 0.35 0.53 0.72 1.07 1.32 1.62 2.34

190.83 5443.00 5432.75 0.054 11.17 119.09 5432.75 5427.43 0.045 20 4.23 0.47 11.64 20.37 11.64 1.55 1.95 2.64 3.25 4.17 4.88 5.64 7.60 0.29 0.37 0.59 0.88 1.49 1.92 2.46 3.68

Calculation of Peak Runoff using Rational MethodCalculation of Peak Runoff using Rational Method

Rainfall Intensity, I (in/hr) Peak Flow, Q (cfs)Overland (Initial) Flow Time Channelized (Travel) Flow Time Time of Concentration

I ��/ℎ� � a ∗ P� b t� t� �

0.395 1.1 � C� L�

S� t� � L�

60K S�

L�

60V�

Computed t� � t� t�

Regional t� � 26 � 17i

L�

60 14i 9 S�

Selected t� � max t3�4�353 , min Computed t� , Regional t� t� 3�4�353� 5 (urban) t� 3�4�353� 10 (non-urban)

Q 89: � CIA

Project 04 _MHFD-Rational v3.xlsm, Rational Calcs 5/11/2026, 17:11

APPENDIX B

HYDRAULICS

ALLOWABLE CAPACITY FOR ONE-HALF OF STREET (Minor & Major Storm) (Based on Regulated Criteria for Maximum Allowable Flow Depth and Spread)

Project: Sidewalk Gaps - Project 04

Inlet ID: Inlet 4.01

Gutter Geometry:

Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft

Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.018 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020) nBACK = 0.013

Height of Curb at Gutter Flow Line HCURB = 6.00 inches

Distance from Curb Face to Street Crown TCROWN = 13.5 ft

Gutter Width W = 2.00 ft

Street Transverse Slope SX = 0.022 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 = 13.5 13.5 ft

Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 6.0 12.0 inches

Check boxes are not applicable in SUMP conditions

MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm

MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow = SUMP SUMP cfs

MHFD-Inlet, Version 6.00 (August 2025)

INLET IN A SUMP OR SAG LOCATION

Design Information (Input) MINOR MAJOR

Type of Inlet Type = Wheat Ridge Combination

Local Depression (additional to continuous gutter depression 'a' from above) alocal = 2.00 2.00 inches

Number of Unit Inlets (Grate or Curb Opening) No = 2 2

Water Depth at Flowline (outside of local depression) Ponding Depth = 6.0 12.0 inches

Grate Information MINOR MAJOR

Length of a Unit Grate Lo (G) = 2.75 2.75 feet

Width of a Unit Grate Wo = 1.37 1.37 feet

Open Area Ratio for a Grate (typical values 0.15-0.90) Aratio = 0.65 0.65

Clogging Factor for a Single Grate (typical value 0.50 - 0.70) Cf (G) = 0.50 0.50

Grate Weir Coefficient (typical value 2.15 - 3.60) Cw (G) = 3.60 3.60

Grate Orifice Coefficient (typical value 0.60 - 0.80) Co (G) = 0.67 0.67

Curb Opening Information MINOR MAJOR

Length of a Unit Curb Opening Lo (C) = 2.88 2.88 feet

Height of Vertical Curb Opening in Inches Hvert = 6.00 6.00 inches

Height of Curb Orifice Throat in Inches Hthroat = 5.25 5.25 inches

Angle of Throat Theta = 0.00 0.00 degrees

Side Width for Depression Pan (typically the gutter width of 2 feet) Wp = 2.00 2.00 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) = 3.70 3.70 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70) Co (C) = 0.66 0.66

Low Head Performance Reduction (Calculated) MINOR MAJOR

Depth for Grate Midwidth dGrate = 0.55 1.05 ft

Depth for Curb Opening Weir Equation dCurb = 0.33 0.83 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate = 0.74 1.00

Curb Opening Performance Reduction Factor for Long Inlets RFCurb = N/A N/A

Combination Inlet Performance Reduction Factor for Long Inlets RFCombination = 0.72 1.00

MINOR MAJOR

Total Inlet Interception Capacity (assumes clogged condition) Qa = 7.2 23.3 cfs

Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak) Q PEAK REQUIRED = 3.9 12.6 cfs

H-Vert H-Curb

Lo (C)

Lo (G)

Override Depths

Project: Sidewalk Gaps - Project 04

Inlet ID: Inlet 4.02 Full Section

Gutter Geometry:

Maximum Allowable Width for Spread Behind Curb TBACK = 5.0 ft

Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.014 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020) nBACK = 0.013

Height of Curb at Gutter Flow Line HCURB = 6.00 inches

Distance from Curb Face to Street Crown TCROWN = 19.0 ft

Gutter Width W = 2.00 ft

Street Transverse Slope SX = 0.021 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 = 19.0 19.0 ft

Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 6.0 12.0 inches

Check boxes are not applicable in SUMP conditions

MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm

MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow = SUMP SUMP cfs

Local Depression (additional to continuous gutter depression 'a' from above) alocal = 2.00 2.00 inches

Number of Unit Inlets (Grate or Curb Opening) No = 1 1

Water Depth at Flowline (outside of local depression) Ponding Depth = 6.0 6.2 inches

Grate Information MINOR MAJOR

Length of a Unit Grate Lo (G) = 2.75 2.75 feet

Width of a Unit Grate Wo = 1.37 1.37 feet

Open Area Ratio for a Grate (typical values 0.15-0.90) Aratio = 0.65 0.65

Clogging Factor for a Single Grate (typical value 0.50 - 0.70) Cf (G) = 0.50 0.50

Grate Weir Coefficient (typical value 2.15 - 3.60) Cw (G) = 3.60 3.60

Grate Orifice Coefficient (typical value 0.60 - 0.80) Co (G) = 0.67 0.67

Curb Opening Information MINOR MAJOR

Length of a Unit Curb Opening Lo (C) = 2.88 2.88 feet

Height of Vertical Curb Opening in Inches Hvert = 6.00 6.00 inches

Height of Curb Orifice Throat in Inches Hthroat = 5.25 5.25 inches

Angle of Throat Theta = 0.00 0.00 degrees

Side Width for Depression Pan (typically the gutter width of 2 feet) Wp = 2.00 2.00 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) = 3.70 3.70 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70) Co (C) = 0.66 0.66

Low Head Performance Reduction (Calculated) MINOR MAJOR

Depth for Grate Midwidth dGrate = 0.55 0.57 ft

Depth for Curb Opening Weir Equation dCurb = 0.33 0.35 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate = 0.96 1.00

Curb Opening Performance Reduction Factor for Long Inlets RFCurb = N/A N/A

Combination Inlet Performance Reduction Factor for Long Inlets RFCombination = 0.95 0.98

MINOR MAJOR

Total Inlet Interception Capacity (assumes clogged condition) Qa = 5.4 5.8 cfs

Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak) Q PEAK REQUIRED = 0.5 1.6 cfs

H-Vert H-Curb

Lo (C)

Lo (G)

Project: Sidewalk Gaps - Project 04

Inlet ID: Inlet 4.02 Reduced Sect

Gutter Geometry:

Maximum Allowable Width for Spread Behind Curb TBACK = 10.0 ft

Side Slope Behind Curb (leave blank for no conveyance credit behind curb) SBACK = 0.017 ft/ft Manning's Roughness Behind Curb (typically between 0.012 and 0.020) nBACK = 0.013

Height of Curb at Gutter Flow Line HCURB = 6.00 inches

Distance from Curb Face to Street Crown TCROWN = 14.0 ft

Gutter Width W = 2.00 ft

Street Transverse Slope SX = 0.033 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 = 14.0 14.0 ft

Max. Allowable Depth at Gutter Flowline for Minor & Major Storm dMAX = 6.0 12.0 inches

Check boxes are not applicable in SUMP conditions

MINOR STORM Allowable Capacity is not applicable to Sump Condition Minor Storm Major Storm

MAJOR STORM Allowable Capacity is not applicable to Sump Condition Qallow = SUMP SUMP cfs

Local Depression (additional to continuous gutter depression 'a' from above) alocal = 2.00 2.00 inches

Number of Unit Inlets (Grate or Curb Opening) No = 1 1

Water Depth at Flowline (outside of local depression) Ponding Depth = 6.0 6.7 inches

Grate Information MINOR MAJOR

Length of a Unit Grate Lo (G) = 2.75 2.75 feet

Width of a Unit Grate Wo = 1.37 1.37 feet

Open Area Ratio for a Grate (typical values 0.15-0.90) Aratio = 0.65 0.65

Clogging Factor for a Single Grate (typical value 0.50 - 0.70) Cf (G) = 0.50 0.50

Grate Weir Coefficient (typical value 2.15 - 3.60) Cw (G) = 3.60 3.60

Grate Orifice Coefficient (typical value 0.60 - 0.80) Co (G) = 0.67 0.67

Curb Opening Information MINOR MAJOR

Length of a Unit Curb Opening Lo (C) = 2.88 2.88 feet

Height of Vertical Curb Opening in Inches Hvert = 6.00 6.00 inches

Height of Curb Orifice Throat in Inches Hthroat = 5.25 5.25 inches

Angle of Throat Theta = 0.00 0.00 degrees

Side Width for Depression Pan (typically the gutter width of 2 feet) Wp = 2.00 2.00 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) = 3.70 3.70 Curb Opening Orifice Coefficient (typical value 0.60 - 0.70) Co (C) = 0.66 0.66

Low Head Performance Reduction (Calculated) MINOR MAJOR

Depth for Grate Midwidth dGrate = 0.55 0.61 ft

Depth for Curb Opening Weir Equation dCurb = 0.33 0.39 ft Grated Inlet Performance Reduction Factor for Long Inlets RFGrate = 0.96 1.00

Curb Opening Performance Reduction Factor for Long Inlets RFCurb = N/A N/A

Combination Inlet Performance Reduction Factor for Long Inlets RFCombination = 0.95 1.00

MINOR MAJOR

Total Inlet Interception Capacity (assumes clogged condition) Qa = 5.4 6.4 cfs

Inlet Capacity IS GOOD for Minor and Major Storms (>Q Peak) Q PEAK REQUIRED = 0.5 1.6 cfs

H-Vert H-Curb

Lo (C)

Lo (G)

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15" domed grate will be used. See next sheet for inlet capacity curve

3130 Verona Avenue • Buford, GA 30518

(866) 888-8479 / (770) 932-2443 • Fax: (770) 932-2490

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10

C ap ac it y (c fs

Head (ft)

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Project:

ID:

47187.82

Design Information (Input):

Circular Culvert: Barrel Diameter in Inches D = 18 inches

Inlet Edge Type (Choose from pull-down list) Square Edge with Headwall

OR:

Box Culvert: Barrel Height (Rise) in Feet H (Rise) = ft

Barrel Width (Span) in Feet W (Span) = ft

Inlet Edge Type (Choose from pull-down list)

1.50

Number of Barrels # Barrels = 1

Inlet Elevation at Culvert Invert 5425.05 Elev IN = 5425.19 ft

Outlet Elevation OR Slope 0.0053 So = 0.0053 ft/ft

Culvert Length L = 25.69 ft

Manning's Roughness n = 0.015

Bend Loss Coefficient Kb = 0

Exit Loss Coefficient Kx = 1

Design Information (calculated):

Entrance Loss Coefficient Ke = 0.50

Friction Loss Coefficient Kf = 0.62

Sum of All Loss Coefficients Ks = 2.12

Minimum Energy Condition Coefficient KElow = 0.0265

Orifice Inlet Condition Coefficient Cd = 0.60

Calculations of Culvert Capacity (output): Backwater calculations required to obtain Outlet Control Flowrate when HWo < 0.75 * Culvert Rise

Headwater Tailwater Inlet Inlet Outlet Controlling Flow

Surface Surface Control Control Control Culvert Control

Elevation Elevation Equation Flowrate Flowrate Flowrate Used

(ft) (ft) Used (cfs) (cfs) (cfs)

5425.19 No Flow (WS < inlet) 0.00 0.00 0.00 N/A

5426.00 Regression Eqn. 2.35 #N/A #N/A #N/A

5427.00 Regression Eqn. 7.94 7.87 7.87 OUTLET

5427.78 Regression Eqn. 11.22 11.25 11.22 INLET

5428.78 Regression Eqn. 14.31 14.53 14.31 INLET

Processing Time: 66.41 ms

CULVERT SIZING (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)

Wheat Ridge Sidewalk Gaps - Project 04 Pipe from Inlet 4.01

MHFD-Culvert, Version 4.01 (April 2025)

Project 04_4.01_MHFD-Culvert_v4.01.xlsm, Culvert Rating 5/13/2026, 15:28

CULVERT SIZING (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)

Wheat Ridge Sidewalk Gaps - Project 04 Pipe from Inlet 4.01

MHFD-Culvert, Version 4.01 (April 2025)

5425.19

5425.69

5426.19

5426.69

5427.19

5427.69

5428.19

5428.69

5429.19

0 5 10 15 20

S ta g e fe e t, e le v

Discharge (cfs)

STAGE-DISCHARGE CURVE FOR THE CULVERT

Inlet Control Outlet Control Stage-Discharge

Project 04_4.01_MHFD-Culvert_v4.01.xlsm, Culvert Rating 5/13/2026, 15:28

47187.82

Design Information (Input):

Circular Culvert: Barrel Diameter in Inches D = 15 inches

Inlet Edge Type (Choose from pull-down list) Square Edge with Headwall

OR:

Box Culvert: Barrel Height (Rise) in Feet H (Rise) = ft

Barrel Width (Span) in Feet W (Span) = ft

Inlet Edge Type (Choose from pull-down list)

1.25

Number of Barrels # Barrels = 1

Inlet Elevation at Culvert Invert 5424.31 Elev IN = 5424.8 ft

Outlet Elevation OR Slope 0.01 So = 0.01 ft/ft

Culvert Length L = 49.35 ft

Manning's Roughness n = 0.015

Bend Loss Coefficient Kb = 0

Exit Loss Coefficient Kx = 1

Design Information (calculated):

Entrance Loss Coefficient Ke = 0.50

Friction Loss Coefficient Kf = 1.52

Sum of All Loss Coefficients Ks = 3.02

Minimum Energy Condition Coefficient KElow = 0.0089

Orifice Inlet Condition Coefficient Cd = 0.60

Calculations of Culvert Capacity (output): Backwater calculations required to obtain Outlet Control Flowrate when HWo < 0.75 * Culvert Rise

Headwater Tailwater Inlet Inlet Outlet Controlling Flow

Surface Surface Control Control Control Culvert Control

Elevation Elevation Equation Flowrate Flowrate Flowrate Used

(ft) (ft) Used (cfs) (cfs) (cfs)

5425.00 Min. Energy. Eqn. 0.13 #N/A #N/A #N/A

5426.00 Regression Eqn. 3.74 4.53 3.74 INLET

5427.00 Regression Eqn. 7.24 7.03 7.03 OUTLET

5427.68 5427.40 Regression Eqn. 8.83 3.02 3.02 OUTLET

5428.68 5427.40 Orifice Eqn. 10.74 6.42 6.42 OUTLET

Processing Time: 70.31 ms

CULVERT SIZING (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)

Wheat Ridge Sidewalk Gaps - Project 04 Pipe from Inlet 4.02

Project 04_4.02_MHFD-Culvert_v4.01.xlsm, Culvert Rating 5/13/2026, 15:29

CULVERT SIZING (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)

Wheat Ridge Sidewalk Gaps - Project 04 Pipe from Inlet 4.02

MHFD-Culvert, Version 4.01 (April 2025)

5425.5

5426.5

5427.5

5428.5

0 2 4 6 8 10 12

S ta g e fe e t, e le v

Discharge (cfs)

STAGE-DISCHARGE CURVE FOR THE CULVERT

Project 04_4.02_MHFD-Culvert_v4.01.xlsm, Culvert Rating 5/13/2026, 15:29

47187.82

Design Information (Input):

Circular Culvert: Barrel Diameter in Inches D = 12 inches Very Small Culvert

Inlet Edge Type (Choose from pull-down list) Square Edge with Headwall D >= 15 inches expected

OR:

Box Culvert: Barrel Height (Rise) in Feet H (Rise) = ft

Barrel Width (Span) in Feet W (Span) = ft

Inlet Edge Type (Choose from pull-down list)

1.00

Number of Barrels # Barrels = 1

Inlet Elevation at Culvert Invert 5424.91 Elev IN = 5425.05 ft

Outlet Elevation OR Slope 0.01 So = 0.01 ft/ft

Culvert Length L = 14.36 ft

Manning's Roughness n = 0.012

Bend Loss Coefficient Kb = 0

Exit Loss Coefficient Kx = 1

Design Information (calculated):

Entrance Loss Coefficient Ke = 0.50

Friction Loss Coefficient Kf = 0.38

Sum of All Loss Coefficients Ks = 1.88

Minimum Energy Condition Coefficient KElow = 0.0125

Orifice Inlet Condition Coefficient Cd = 0.61

Calculations of Culvert Capacity (output):

Headwater Tailwater Inlet Inlet Outlet Controlling Flow

Surface Surface Control Control Control Culvert Control

Elevation Elevation Equation Flowrate Flowrate Flowrate Used

(ft) (ft) Used (cfs) (cfs) (cfs)

5425.00 No Flow (WS < inlet) 0.00 0.00 0.00 N/A

5426.00 Regression Eqn. 2.11 2.36 2.11 INLET

5427.00 Regression Eqn. 4.49 4.89 4.49 INLET

5427.43 Regression Eqn. 5.17 5.72 5.17 INLET

5428.10 5427.68 Orifice Eqn. 6.11 2.99 2.99 OUTLET

Processing Time: 74.22 ms

CULVERT SIZING (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)

Wheat Ridge Sidewalk Gaps - Project 04 Pipe from Inlet 4.03

Project 04_4.03_MHFD-Culvert_v4.01.xlsm, Culvert Rating 5/13/2026, 15:27

D >= 15 inches expected

CULVERT SIZING (INLET vs. OUTLET CONTROL WITH TAILWATER EFFECTS)

Wheat Ridge Sidewalk Gaps - Project 04 Pipe from Inlet 4.03

MHFD-Culvert, Version 4.01 (April 2025)

5425.5

5426.5

5427.5

5428.5

0 1 2 3 4 5 6 7

S ta g e fe e t, e le v

Discharge (cfs)

STAGE-DISCHARGE CURVE FOR THE CULVERT

Project 04_4.03_MHFD-Culvert_v4.01.xlsm, Culvert Rating 5/13/2026, 15:27

APPENDIX C

REFERENCE INFORMATION

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 Golden Area, Colorado, Parts of Denver, Douglas, Jefferson, and Park Counties West 35th Avenue and Parfet Street

Natural Resources Conservation Service

May 11, 2026

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 http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/ http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/ https://offices.sc.egov.usda.gov/locator/app?agency=nrcs http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?cid=nrcs142p2_053951 http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/?cid=nrcs142p2_053951 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.

Contents Preface How Soil Surveys Are Made Soil Map

Soil Map Legend Map Unit Legend Map Unit Descriptions

Golden Area, Colorado, Parts of Denver, Douglas, Jefferson, and Park Counties

32—Denver-Kutch-Urban land complex, 5 to 9 percent slopes 61—Haverson loam, 3 to 9 percent slopes 106—Nunn-Urban land complex, 2 to 5 percent slopes

References

How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity.

Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA.

The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape.

Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries.

Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units).

Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil scientists classified and named the soils in the survey area, they compared the 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 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately.

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.

Soil Map

489590 489620 489650 489680 489710 489740 489770 489800 489830 489860 489890

39° 46' 0'' N

5°

' 1 8'

' W 39° 46' 0'' N

5°

' 4

'' W

39° 45' 53'' N

5°

' 1

8' ' W

39° 45' 53'' N

5°

' 4

'' W

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 50 100 200 300

Feet 0 20 40 80 120

Meters Map Scale: 1:1,520 if printed on A landscape (11" x 8.5") 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: Golden Area, Colorado, Parts of Denver, Douglas, Jefferson, and Park Counties Survey Area Data: Version 20, Aug 29, 2025

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Jul 1, 2020—Jul 2, The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background

MAP LEGEND MAP INFORMATION

imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Map Unit Legend

Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI

32 Denver-Kutch-Urban land complex, 5 to 9 percent slopes

2.5 62.2%

61 Haverson loam, 3 to 9 percent slopes

0.7 17.0%

106 Nunn-Urban land complex, 2 to 5 percent slopes

0.8 20.8%

Totals for Area of Interest 4.0 100.0%

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…

This is the start of the file's text. The full file is on GovTribe.

File details come from the government source that posted it. Updated Aug 18, 2026.