ND FTFW DESL 11(4) HYD Memo_AD_signsealed.pdf

CFLHD | ND FTFW DESL 11(4)

Final Hydraulics Recommendations

Memo hdrinc.com 1670 Broadway Suite 3400 Denver, CO 80202-4824

(303) 764-1520

Date: Friday, November 01, 2024

Project: ND FTFW DESL 11(4)

To: Luis Calderon, CFLHD; Nate Mascarenas, CFLHD

From: Amy Finseth, HDR

Subject: Final Hydraulics Recommendations Memorandum

Introduction

Auto Tour Route ND FTFW DESL 11(4) Lower Lake Road is located in the Des Lacs National

Wildlife Refuge near Kenmare, North Dakota (ND) in Ward County. Kenmare is located approximately 60 miles north-west of Minot, ND. Route 011 (RTE11) is a two-lane gravel road which has been deteriorating due to weather events, drainage and geotechnical issues and lack of routine maintenance. This is Phase 6 of work along RTE11. The scope of work includes spot aggregate resurfacing and subexcavation in unstable soil locations, ditch grading and stabilization, culvert cleaning and replacement. The Project extends from milepost (MP) 0.0 to

MP 2.0. The total length of Phase 6 is approximately two miles. This has been further divided into Schedule A, X, Y and Z. All drainage work will be included in Schedule A between Station

15+75 to 89+50. Option Z would include the same work description between Station 89+50 to

118+85.

From the centerline of road to the west is Canadian Pacific Railroad right-of-way (ROW). On the east the road alternates between Refuge, City of Kenmare and Ward County ROW. A

Memorandum of Understanding (MOU) has been written and approved between the Refuge, Canadian Pacific Railroad, City of Kenmare, and Ward County.

The scope of work initially included roadbed reconditioning of aggregate resurfacing, subexcavation in unstable soil locations, evaluation of five ditch locations of concern for capacity and evaluation of the existing crossing at 492nd Street. An existing condition hydrologic and hydraulic analysis of each culvert was done during the 30% Design. There were six specific locations identified by the Refuge with drainage concerns which include the five ditch capacity locations and the culvert at 492nd Street. To that end those five locations do not have defined roadside ditches and runoff drains across RTE11. At 492nd Street north-west the need for a new pipe was evaluated to address drainage issues. Design will follow the criteria and guidance in

Federal Highway Associations Project Development and Design Manual (PDDM) and any applicable local criteria.

08/19/2025

Figure 1 Location Maps

(Images from NDDOT)

Criteria Hydrologic and hydraulic components of the project include developing existing conditions hydrology and culvert analysis. Proposed ditches will be added at specific locations where there are existing drainage concerns. Ditch stabilization measures were also evaluated at select locations.

The drainage criteria developed for this Project is based on the U.S. Department of

Transportation Federal Highway Administration (FHWA) Project Development and Design

Manual (PDDM) and local criteria from North Dakota Department of Transportation (NDDOT)

Drainage Manual (DM) Chapter V: Hydraulic Studies and Drainage Design. Ward County does not have design criteria. Therefore, NDDOT was referenced for local criteria.

The roadway classification is designated as a low-standard road. This is typically determined by traffic count and design speed. Traffic data was not provided but is assumed to be less than 50 average daily traffic (ADT).

Table 1 summarizes drainage design criteria for the drainage components included in the

Project.

Table 1 H&H Criteria

Design Feature PDDM Criteria

Peak Flow Methods Rational Method – up to 200 acres

Regression Equations for areas > 200 acres

Culverts

Capacity Design and Stability

Design: 25-year (cross culverts)

10-year (parallel culverts)

*Check: 100-year

Headwater

Existing culverts: water surface elevation ≤ the shoulder hinge point

New culverts: water surface elevation ≤ the bottom of the roadway aggregate base layer

Or a water surface elevation limited by unacceptable hazards to human life or property

HW/D: 48-inch or smaller = 1.5, > 48-inch = 1.2

Minimum Size Cross culvert: 24-inch or equivalent

Parallel culvert: 18-inch or equivalent

Pipe Material

Minimum pipe classification

RCP: Class II, Metal 0.064"

50-year service life

Minimum and

Maximum Outlet Velocity

Minimum: 3 fps

Maximum: as determined by HEC22; matching existing channel velocities.

Outlet Protection

* Vo>10 fps shall use riprap aprons. Methods in HEC 14 with the exception of thickness. Max thickness allowed in 3 feet.

* where additional protection may be needed : articulating concrete block mats, internal dissipation with baffle rings or broke back culverts.

Design Feature PDDM Criteria

Roadside Ditches

Capacity Design

10-year storm event

New: water surface elevation ≤ bottom of roadway aggregate base layer

Existing: water surface elevation ≤ shoulder hinge point

Stability Design

Permanent Lining: 10-year flood

Temporary lining: 2-year flood

Determined by permissible shear stress

Slope Minimum: 0.5%

*Indicates local preference/criteria in addition to the PDDM.

Hydrology Hydrology was developed for local basins, up to 200 acres, using the rational method. The

National Oceanic and Atmospheric Administration (NOAA) Precipitation Frequency Data Server was used to develop an intensity duration frequency (IDF) curve used in the rational method.

NOAA Atlas 14 precipitation intensities for the Project are listed in Table 1.

Table 2 NOAA Atlas 14, Point Precipitation Frequency Estimates, Rainfall Intensity

Duration (minutes)

2-Year (inches/hour)

10-Year (inches/hour)

25-Year (inches/hour)

50-Year (inches/hour)

100-Year (inches/hour)

5 3.95 6.23 7.63 8.71 9.77

10 2.89 4.57 5.59 6.38 7.15

15 2.35 3.71 4.54 5.18 5.81

30 1.52 2.41 2.96 3.37 3.78

60 0.94 1.48 1.8 2.06 2.31

Soil information was determined using the Natural Resources Conservation Service (NRCS)

Web Soil Survey for Ward County, North Dakota. The hydrologic soil for the surrounding area is

B and C. The majority of the basin is group B. The upper ranges of offsite basins include smaller areas of group C soils. The hydrologic soil report is included in Appendix A.

Basins exceeding 200 acres used USGS regional regression equations, in accordance with the methods described in U.S. Geological Survey Scientific Investigations Report 2015-5096.

Calculation of design discharge was in accordance with the US Geological Survey Water

Resources Investigation Report 92-4020 “Techniques for Estimating Peak-Flow Frequency

Relations for North Dakota Streams”. Methods referenced from the NDDOT Design Manual, Chapter 5, Hydraulic Studies, and Drainage Design. North Dakota has three hydrologic zones;

the project falls in Zone C. A map from Report 92-4020 and the regression equations for North

Dakota are included in Appendix A.

Hydrologic zone C equations for the frequencies used on the project are listed in Table 3.

Table 3 USGS Regression Equations for North Dakota, Hydrologic Zone C

Recurrence

Interval

(years)

Equation

2 log Q50% = 0.555 + 0.425 x log (DRNAREA) + 0.301 x log (RUGGED)

10 log Q10% = 1.187 + 0.476 x log (DRNAREA) + 0.294 x log (RUGGED)

25 log Q4% = 1.379 + 0.491 x log (DRNAREA) + 0.292 x log (RUGGED)

50 log Q2% = 1.493 + 0.500 x log (DRNAREA) + 0.291 x log (RUGGED)

100 log Q1% = 1.591 + 0.507 x log (DRNAREA) + 0.290 x log (RUGGED)

Runoff drains from northeast to southwest across the site. Basin Maps are included in Appendix

A. Basins are primarily large undeveloped offsite basins with landcover consistent of meadow grass with shallow to steeper drainages. Smaller basins drain along RTE 011 contributing to roadside ditches and driveway culverts. This project evaluated several frequencies including 2-, 10-, 50- and 100-year. For clarity not all basin information is included in the summary table below, but full calculations are included in Appendix A. Table 4 provides a list of each basin contributing to the Site.

Table 4 Hydrologic Calculations

Basin ID Area

(acres)

Q2

(cfs)

Q10

(cfs)

Q25

(cfs)

Q50

(cfs)

Q100

(cfs)

B18 35.70 5.6 13.1 21.0 29.7 39.6

B23 18.66 4.9 10.9 17.1 23.9 31.6

B34 85.06 19.4 40.9 62.8 85.8 112.2

B43 4.88 2.2 4.3 6.3 8.3 10.7

B50 97.02 18.9 39.0 58.8 80.0 104.0

B52 0.21 0.3 0.6 0.8 0.9 1.1

B53 38.67 6.1 13.8 22.2 31.1 41.7

B55 3.54 1.8 3.4 4.8 6.3 7.9

B63 10.28 2.7 6.0 9.5 13.4 17.7

B67 9.22 2.6 5.6 8.7 12.0 15.7

B70 5.08 1.6 3.4 5.2 7.2 9.4

B72 65.23 11.8 25.7 40.3 55.7 73.7

B84 18.80 5.3 10.6 15.7 20.9 26.9

B87 6.23 2.1 4.3 6.6 9.1 11.9

B97 26.82 5.5 11.7 18.0 24.7 32.5

B99 90.22 19.6 40.4 61.0 82.7 107.6

B104 14.21 3.9 8.0 12.1 16.3 21.3

Additional information is included in Appendix A including basin maps, rational calculations, regression calculations, soil data and rainfall data.

Floodplain Impacts

The Project is adjacent to but not located in an area of Federal Emergency Management

Agency (FEMA) mapped floodplain. The adjacent floodplain is mapped Zone A. The Project is located on FEMA panels 38101C0090D and 38101C0095D. These panels as well as the Index for Ward County is included in Appendix A.

Hydraulics

Existing Conditions

There are thirteen existing culverts that cross RTE011 and one under 492nd Street. An existing conditions analysis was done for each culvert at 30% design. The analysis was done using

FHWA HY8 software. Most culverts are corrugated metal pipe (CMP) (10) some with headwalls.

Culverts at the northern limits of the project (4) are reinforced concrete pipe (RCP). Culvert condition was investigated during the 30% field review. During the field review it was determined that the majority of cross culverts were in good condition. There were four locations identified that need replacement, one location had deteriorated headwalls, and two locations with significant debris and clogging.

Table 5 summarizes the existing culverts and the hydraulic results for the major (100-year) analysis. Results for all culverts for 2-, 10-, and 50 are included in a summary table in Appendix

B. Culverts were analyzed for existing conditions with the existing roadway edge of pavement elevations.

Table 5 Existing Culverts

Culvert ID

Approximate

Roadway

Station

Diameter

(inches) Material

Q100

(cfs)

Edge of

Gravel

Elevation

(feet)

Headwater

Elevation

(feet)

HW/D

C18 18+26 24 CMP 39.6 1797.2 1797.53 1.0

C23 23+36 24 CMP 31.6 1789.3 1789.69 1.8

C34 33+90 18 CMP 112.2 1802.0 1803.14 2.2

C43 43+32 30 CMP 10.7 1801.4 1796.56 0.7

C50 49+74 30 CMP 109.1 1805.3 1805.6 4.6

C55 55+04 Rt 18 CMP 7.9 1817.0 1816.05 1.4

C63 63+40 24 CMP 17.7 1824.6 1818.85 1.2

C67 67+30 30 CMP 24.3 1812.9 1812.86 1.0

C72 72+15 2 x 30 CMP 73.7 1803.2 1803.18 1.7

C84 83+75 30 CMP 35.0 1818.2 1818.23 1.1

C97 97+33 24 RCP 32.5 1800.5 1800.74 2.4

C99 99+40 24 RCP 107.6 1803.1 1803.71 8.1

C104 104+26 24 RCP 21.3 1818.8 1817.03 1.5

C111 110+87 24 RCP 240.6 1800.0 1800.79 4.8

The Refuge staff identified four areas of concern where ditch improvements are needed. Runoff drains over RTE011 because there are no defined roadside ditches to capture runoff on the north side of the road. Runoff down 492nd Street has caused erosion and sedimentation in the ditch and culvert at the intersection with RTE011. The grade down 492nd Street is greater than

10%. There are defined ditches on the upper sections of 492nd Street that drain to the south toward RTE011 but on the west the flows are directed around a berm to the west and south to a roadside ditch that runs south-east along RTE011 to an 18-inch culvert under 492nd Street. See basin map, basin ID B55.

Proposed Design

CULVERTS

An existing conditions analysis of all culverts was completed during 30% design. Not all met current design standards. However, to work within the funding of the project and based on findings of the field review the proposed culvert work will be reduced. Initially all culverts were planned to be replaced in-kind with RCP. As mentioned previously during the field review it was found that most culverts were in good condition and only two need to be replaced. Those culverts are currently CMP and will be replaced with the same diameter RCP, flared end sections and riprap outlet protection. Table 6 lists the culverts to be replaced.

Table 6 Culvert Replacement

RTE11 Station Diameter

(inches)

18+26 24

72+15 2 x 30

There were two culverts that were in good condition but need to be cleaned of debris. They are located at Station 23+36 and 33+90.

One culvert located at Station 83+52 is in good condition, but headwalls have deteriorated. The headwalls will be removed and replaced with flared end sections with riprap outlet protection.

One culvert was scoped to be added if found necessary to improve conditions at 492nd Street.

Analysis of this location found that the existing pipe diameter meets current design standards listed in the criteria section and the primary problem here was erosion of the slopes from runoff from the north into this culvert. This location will replace the existing 18-inch CMP with an 18-inch RCP, flared end sections and riprap outlet protection. The hydraulic results of the analysis are included in Table 7.

The replacement culvert will convey the 25-year peak runoff per the PDDM. In addition, roadway improvements include a ditch that will convey the design flow to meet current ditch criteria to the next downstream culvert (49+74).

Table 7 Proposed Culvert Replacements

Culvert ID Roadway

Station

Diameter

(inches) Material

Q25

(cfs)

Bottom of

Aggregate base layer

Elevation

(feet)

Headwater

Elevation

(feet)

HW/D

Outlet

Velocity

(fps)

C55 55+04 Rt

RCP 4.8 1817.0 1815.3 0.6 4.7

The DM recommends outlet protection for outlet velocities over 7 fps in locations of unstable soils or over 10 fps. Standard riprap aprons are proposed on culverts list above with improvements to replace the culvert or end treatments in accordance with Federal Highway

Administration Standard CFLHD Detail, C251-50, Placed Riprap at Culvert Outlets. Culverts to be replaced will have flared end sections

DITCHES

Locations for ditch improvements were evaluated for the 10-year design storm for conveyance as well as stability. The analysis used FHWA Hydraulic Toolbox. Proposed ditches use a V-section with 4:1 side slopes off the road and variable backslope ranging from 2:1 to 6:1.

A stability analysis was done for the same locations. The stability analysis was also done using

FHWA Hydraulic Toolbox. Ditches were initially analyzed with vegetative lining, if it was found to be unstable turf reinforcing mats were analyzed. The vegetation parameters used a fair condition with mixed growth. The maximum shear stress for soil is 0.04, vegetation 0.569 and rolled erosion control product (RECP) is 3.11 lb/ft2 for turf reinforcing mat (TRM) type 5.A as defined by FLH FP14 Standard Specifications for Construction of Road and Bridges on Federal

Highway Projects Section S713-14 Roadside Improvement Materials, section 713.18 Turf

Reinforcement Mats, Table 713-4 Turf Reinforcement Mats. The properties for TRM 5.A allows for a minimum shear stress for channel applications of 6.0 lb/ft2 and a minimum tensile strength of 125 lb/ft. Table 8 summarizes the capacity and lining recommendations for the five ditch sections.

Table 8 Proposed Ditch Summary

Station

Longitudinal slope

(foot/foot)

Q10

(cfs)

Depth of

Flow

(feet)

Lining

Material

Max Shear

Stress

(lb/ft2)

Permissible

Shear Stress on TRM

(lb/ft2)

50+85 to 52+20

Lt 0.02-0.05 0.6 0.3 TRM (5.A) 0.785 3.1

50+30 to 53+50

Rt 0.01-0.03 16.1 1.0 TRM (5.A) 1.69 3.1

55+27 to 56+76

Rt 0.03-0.08 3.4 0.5 TRM (5.A) 2.155 3.1

67+30 to 71+10

Rt 0.02-0.04 3.4 0.5 TRM (5.A) 0.900 3.1

84+00 to 85+50

Rt 0.02-0.03 4.3 0.6 TRM (5.A) 1.000 3.1

Additional ditch segments that were not included in the hydraulic analysis will also be lined with

TRM 5.A. These locations include ditch excavation and ditch reconditioning activity identified on the construction plans. Culvert and ditch calculations are included in Appendix B.

Stormwater Control Measures

The project’s construction stormwater discharges must include a general stormwater construction permit in accordance with NDR11-0000 00000 effective on April 1, 2020 in conformance with the National Pollutant Discharge Elimination System (NPDES). The contractor will be responsible for acquiring the permit.

FHWA standard erosion and sediment control measures will be used. Areas that are disturbed during construction will be re-established. Anticipated practices include fiber rolls as perimeter control, culvert inlet and outlet protection and in ditches. Proposed ditches should incorporate erosion control blanket to establish vegetation. Permanent controls will include turf reinforcing mats. All disturbed areas will be re-established with native seed.

Summary

The proposed drainage improvements for the project will include select culvert replacement in-kind, improved ditch capacity at select locations along with permanent stabilization to improve specific areas along the project where drainage concerns were identified by the Refuge.

References

• Design of Roadside Channels with Flexible Linings, Federal Highway Administration

(FLH), Hydraulic Engineering Circular (HEC) No. 15, Third Edition. September 2005.

• Detail Drawings: FP-14, Central Federal Lands Highway Division (CFLHD).

• Drainage Manual – Chapter V : Hydraulic Studies and Drainage Design, North Dakota

Department of Transportation (NDDOT). January 2016.

• NDDOT GIS & Mapping, nd.gov. August 2022.

• Highway Hydrology, Federal Highway Administration, Hydraulic Design Series No. 2

(HDS2), FHWA-NHI-02-001. 2002.

• NOAA Atlas 14 Point Precipitation Frequency Estimates, NOAA. July 7, 2022.

• Project Development and Design Manual (PDDM), Federal Lands Highway (FLH).

December 2012.

• Standard Drawings, Federal Lands Highway (FLH).

• Stormwater Permit for Construction Activities, North Dakota Department of

Environmental Quality.

• Web Soil Survey Hydrologic Soil Group – Ward County Area, North Dakota, NRCS. July

7, 2022.

Appendix A

1670 Broadway, Suite 3400, Denver, CO 80202-4824

(303) 764-15201670 Broadway, Suite 3400, Denver, CO US 80202-4824 hdrinc.com

Appendix A

Hydrology

1. Basin Maps

2. Soil Data

3. Precipitation Data

4. Rational Calculations

5. Regression Calculations

6. North Dakota Regression References

7. StreamStats Report

8. FEMA – FIRM Panels

A.1 Basin Maps http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#text http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#dimension http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#text http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#dimension http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#text http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#dimension http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#text http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#dimension http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#text http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#dimension http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#text http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#dimension http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#text http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#dimension http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#text http://flh.fhwa.dot.gov/resources/pse/cadd/styles.htm#dimension 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A.2 Soil Data

Hydrologic Soil Group—Ward County, North Dakota (DesLacs ND FTFW DESL AutoTourRoute)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

7/27/2022

715200 715600 716000 716400 716800 717200 717600

715200 715600 716000 716400 716800 717200 717600

48° 40' 21'' N

2°

' 4 6'

' W 48° 40' 21'' N

2°

' 3

6' ' W

48° 38' 28'' N

2°

' 4

6' ' W

48° 38' 28'' N

2°

' 3

6' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 500 1000 2000 3000

Feet 0 250 500 1000 1500

Meters Map Scale: 1:17,100 if printed on A portrait (8.5" x 11") sheet.

Project

MAP LEGEND MAP INFORMATION

Area of Interest (AOI) Area of Interest (AOI)

Soils Soil Rating Polygons

A

A/D

B

B/D

C

C/D

D

Not rated or not available

Soil Rating Lines A

A/D

B

B/D

C

C/D

D

Not rated or not available

Soil Rating Points A

A/D

B

B/D

C

C/D

D

Not rated or not available

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:20,000.

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: Ward County, North Dakota Survey Area Data: Version 21, Sep 8, 2021

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

Date(s) aerial images were photographed: Jun 29, 2021—Jul 1, 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.

Hydrologic Soil Group—Ward County, North Dakota (DesLacs ND FTFW DESL AutoTourRoute)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

7/27/2022

Hydrologic Soil Group

Map unit symbol Map unit name Rating Acres in AOI Percent of AOI

F147F Buse-Barnes-Darnen loams, 9 to 35 percent slopes

B 273.7 52.8%

F157B Barnes loam, 3 to 6 percent slopes

B 153.7 29.6%

F158A Hamlet-Souris-Tonka complex, 0 to 3 percent slopes

C 41.9 8.1%

F160A Hamlet-Souris loams, 1 to 3 percent slopes

C 47.5 9.2%

F160B Hamlet-Souris loams, 1 to 5 percent slopes

C 1.3 0.3%

F998 Water, miscellaneous 0.3 0.1%

Totals for Area of Interest 518.4 100.0%

Hydrologic Soil Group—Ward County, North Dakota DesLacs ND FTFW DESL AutoTourRoute

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Description

Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms.

The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows:

Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission.

Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture.

These soils have a moderate rate of water transmission.

Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission.

Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission.

If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes.

Rating Options

Aggregation Method: Dominant Condition

Component Percent Cutoff: None Specified

Tie-break Rule: Higher

Hydrologic Soil Group—Ward County, North Dakota DesLacs ND FTFW DESL AutoTourRoute

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

A.3 Precipitation Data

NOAA Atlas 14, Volume 8, Version 2

Location name:

Kenmare, North Dakota, USA*

Latitude:

48.6664°, Longitude:

-102.0661°

Elevation:

1957.7 ft**

* source: ESRI Maps

** source: USGS

POINT PRECIPITATION FREQUENCY ESTIMATES

Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin

NOAA, National Weather Service, Silver Spring, Maryland

PF_tabular | PF_graphical | Maps_&_aerials

PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1

Duration Average recurrence interval (years)

1 2 5 10 25 50 100 200 500 1000

5-min 3.18 (2.44‑4.13)

3.95 (3.04‑5.14)

5.21 (3.98‑6.79)

6.23 (4.75‑8.16)

7.63 (5.62‑10.3)

8.71 (6.26‑11.9)

9.77 (6.82‑13.6)

10.8 (7.27‑15.5)

12.2 (7.91‑17.9)

13.3 (8.40‑19.8)

10-min 2.32 (1.79‑3.02)

2.89 (2.22‑3.76)

3.81 (2.92‑4.97)

4.57 (3.47‑5.98)

5.59 (4.11‑7.52)

6.38 (4.59‑8.69)

7.15 (4.99‑9.98)

7.93 (5.32‑11.3)

8.95 (5.79‑13.1)

9.71 (6.14‑14.5)

15-min 1.89 (1.45‑2.46)

2.35 (1.80‑3.06)

3.10 (2.37‑4.04)

3.71 (2.82‑4.86)

4.54 (3.34‑6.12)

5.18 (3.73‑7.07)

5.81 (4.06‑8.11)

6.45 (4.33‑9.22)

7.28 (4.71‑10.7)

7.90 (5.00‑11.8)

30-min 1.22 (0.934‑1.58)

1.52 (1.17‑1.98)

2.01 (1.54‑2.62)

2.41 (1.84‑3.16)

2.96 (2.17‑3.98)

3.37 (2.43‑4.60)

3.78 (2.64‑5.28)

4.19 (2.81‑6.00)

4.73 (3.06‑6.94)

5.12 (3.24‑7.65)

60-min 0.765 (0.588‑0.995)

0.944 (0.725‑1.23)

1.24 (0.946‑1.61)

1.48 (1.12‑1.93)

1.80 (1.33‑2.43)

2.06 (1.48‑2.81)

2.31 (1.61‑3.22)

2.56 (1.72‑3.66)

2.89 (1.87‑4.25)

3.14 (1.99‑4.69)

2-hr 0.462 (0.359‑0.592)

0.564 (0.438‑0.725)

0.732 (0.568‑0.944)

0.872 (0.672‑1.13)

1.06 (0.793‑1.42)

1.21 (0.884‑1.63)

1.36 (0.962‑1.87)

1.51 (1.03‑2.13)

1.71 (1.12‑2.47)

1.86 (1.19‑2.73)

3-hr 0.346 (0.271‑0.441)

0.417 (0.326‑0.531)

0.534 (0.417‑0.682)

0.632 (0.491‑0.811)

0.769 (0.578‑1.02)

0.875 (0.644‑1.17)

0.983 (0.701‑1.34)

1.09 (0.750‑1.53)

1.24 (0.822‑1.78)

1.35 (0.875‑1.97)

6-hr 0.208 (0.165‑0.262)

0.246 (0.195‑0.309)

0.309 (0.244‑0.390)

0.363 (0.285‑0.460)

0.440 (0.336‑0.575)

0.501 (0.374‑0.662)

0.563 (0.408‑0.761)

0.629 (0.438‑0.870)

0.718 (0.483‑1.02)

0.787 (0.516‑1.13)

12-hr 0.122 (0.098‑0.151)

0.142 (0.114‑0.176)

0.176 (0.141‑0.219)

0.206 (0.164‑0.258)

0.249 (0.193‑0.322)

0.284 (0.215‑0.371)

0.321 (0.235‑0.428)

0.359 (0.254‑0.490)

0.412 (0.281‑0.575)

0.453 (0.301‑0.640)

24-hr 0.070 (0.057‑0.085)

0.082 (0.066‑0.100)

0.102 (0.083‑0.126)

0.120 (0.097‑0.148)

0.145 (0.114‑0.185)

0.166 (0.127‑0.213)

0.187 (0.139‑0.245)

0.209 (0.150‑0.280)

0.239 (0.165‑0.328)

0.263 (0.177‑0.365)

2-day 0.039 (0.032‑0.047)

0.047 (0.038‑0.057)

0.059 (0.049‑0.072)

0.070 (0.057‑0.085)

0.085 (0.067‑0.106)

0.096 (0.075‑0.122)

0.108 (0.081‑0.139)

0.120 (0.087‑0.159)

0.137 (0.096‑0.184)

0.149 (0.102‑0.204)

3-day 0.028 (0.024‑0.034)

0.034 (0.028‑0.041)

0.043 (0.035‑0.051)

0.050 (0.041‑0.060)

0.060 (0.048‑0.075)

0.068 (0.054‑0.086)

0.077 (0.058‑0.098)

0.085 (0.062‑0.111)

0.096 (0.068‑0.129)

0.105 (0.073‑0.142)

4-day 0.023 (0.019‑0.027)

0.027 (0.022‑0.032)

0.034 (0.028‑0.040)

0.039 (0.032‑0.047)

0.047 (0.038‑0.058)

0.053 (0.042‑0.066)

0.060 (0.045‑0.076)

0.066 (0.049‑0.086)

0.075 (0.053‑0.099)

0.081 (0.056‑0.109)

7-day 0.016 (0.013‑0.018)

0.018 (0.015‑0.021)

0.022 (0.018‑0.026)

0.025 (0.021‑0.030)

0.030 (0.024‑0.036)

0.033 (0.026‑0.041)

0.037 (0.028‑0.046)

0.040 (0.030‑0.052)

0.045 (0.033‑0.059)

0.049 (0.034‑0.065)

10-day 0.012 (0.010‑0.014)

0.014 (0.012‑0.016)

0.017 (0.014‑0.020)

0.019 (0.016‑0.023)

0.023 (0.018‑0.027)

0.025 (0.020‑0.031)

0.028 (0.022‑0.035)

0.030 (0.023‑0.039)

0.034 (0.025‑0.044)

0.037 (0.026‑0.048)

20-day 0.008 (0.007‑0.010)

0.009 (0.008‑0.011)

0.011 (0.010‑0.013)

0.013 (0.011‑0.015)

0.015 (0.012‑0.018)

0.016 (0.013‑0.020)

0.018 (0.014‑0.022)

0.019 (0.015‑0.024)

0.021 (0.016‑0.027)

0.023 (0.016‑0.029)

30-day 0.007 (0.006‑0.008)

0.008 (0.007‑0.009)

0.009 (0.008‑0.011)

0.010 (0.009‑0.012)

0.012 (0.010‑0.014)

0.013 (0.011‑0.015)

0.014 (0.011‑0.017)

0.015 (0.012‑0.019)

0.017 (0.012‑0.021)

0.017 (0.013‑0.022)

45-day 0.005 (0.005‑0.006)

0.006 (0.005‑0.007)

0.007 (0.006‑0.008)

0.008 (0.007‑0.010)

0.010 (0.008‑0.011)

0.010 (0.009‑0.012)

0.011 (0.009‑0.013)

0.012 (0.009‑0.015)

0.013 (0.010‑0.016)

0.013 (0.010‑0.017)

60-day 0.005 (0.004‑0.005)

0.005 (0.005‑0.006)

0.006 (0.006‑0.007)

0.007 (0.006‑0.008)

0.008 (0.007‑0.009)

0.009 (0.007‑0.010)

0.010 (0.008‑0.011)

0.010 (0.008‑0.012)

0.011 (0.008‑0.013)

0.011 (0.008‑0.014)

1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).

Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.

Please refer to NOAA Atlas 14 document for more information.

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A.4 Rational Calculations

Rational Method

Runoff Coefficients Project: CFLHD TO13 ND Auto Tour Route Computed: SE Date: 7/25/2022

System Name: Existing Hydrology Checked: AF Date: 7/27/2022

Sub-Basin Data

Basin ID Description

B18 Offsite flows to 24" CMP 35.70 0.11 0.13 0.16 0.21 0.26 0.31 B 85/15 1.6% 0.57 35.13

B23 Offsite flows to 24" CMP 18.66 0.13 0.15 0.18 0.23 0.28 0.33 B 100/0 4.2% 0.78 17.88

B34 Offsite flows to 18" CMP 85.06 0.15 0.18 0.20 0.25 0.30 0.35 B 57/43 0.1% 0.06 85.00

B43 Offsite flows to 30" CMP 4.88 0.20 0.23 0.25 0.30 0.35 0.40 B 100/0 16.7% 0.82 4.07

B50 Offsite flows to 30" CMP 97.02 0.16 0.19 0.21 0.26 0.31 0.36 B 65/35 2.5% 2.40 94.62

B52 Offsite flows to ditch at Sta. 50+75 - 52+25 Lt 0.21 0.60 0.62 0.65 0.70 0.75 0.80 B 100/0 82.7% 0.17 0.04

B53 Offsite flows to ditch at Sta. 50+00 - 53+30 Rt 38.67 0.11 0.14 0.16 0.21 0.26 0.31 B 100/0 2.3% 0.88 37.79

B55 Offsite flows to Ditch Sta. 53+00 to 55+20 Rt / 18" CMP 3.54 0.24 0.27 0.29 0.34 0.39 0.44 B 100/0 24.1% 0.85 2.69

B63 Offsite flows to 24" CMP 10.28 0.12 0.14 0.17 0.22 0.27 0.32 B 100/0 3.3% 0.33 9.95

B67 Offsite flows to 30" CMP 9.22 0.14 0.17 0.19 0.24 0.29 0.34 B 100/0 6.9% 0.64 8.58

B70 Offsite flows to ditch at Sta. 67+50 - 72+00 Rt 5.08 0.14 0.17 0.19 0.24 0.29 0.34 B 100/0 6.7% 0.34 4.74

B72 Offsite flows to 2-30" CMP 65.23 0.13 0.16 0.18 0.23 0.28 0.33 B 91/9 5.4% 3.50 61.73

B84 Offsite flows to 30" CMP 18.80 0.19 0.21 0.24 0.29 0.34 0.39 B 100/0 14.9% 2.80 16.00

B87 Offsite flows to ditch at Sta. 83+50 85+50 Rt 6.23 0.15 0.18 0.20 0.25 0.30 0.35 B 100/0 8.6% 0.54 5.69

B97 Offsite flows to 24" RCP 26.82 0.14 0.17 0.19 0.24 0.29 0.34 B 100/0 7.4% 1.99 24.83

B99 Offsite flows to 24" RCP 90.22 0.16 0.19 0.21 0.26 0.31 0.36 B 95/5 10.8% 9.71 80.51

B104 Offsite flows to 24" RCP 14.21 0.16 0.19 0.21 0.26 0.31 0.36 B 100/0 10.8% 1.54 12.68

** Basins are outside extents of alignment

Type of Drainage Area

C2 C10 C25 C50 C100 C2 C10 C25 C50 C100 C2 C10 C25 C50 C100

Pavement 0.70 0.75 0.80 0.85 0.90 0.73 0.78 0.83 0.88 0.93 0.75 0.80 0.85 0.90 0.95

Meadows 0.10 0.15 0.20 0.25 0.30 0.15 0.20 0.25 0.30 0.35 0.20 0.25 0.30 0.35 0.400.10-0.40

NDDOT Appendix V-03A

Composite

C10

Runoff Coefficient

*C values determined from ND DOT, Chapter 5 Hydraulic Studies and Drainage Design, Section 3: Appendix A: Rational Method Runoff Coefficients

Composite

C25

Composite

C2

Composite

C5

Primary

Hydrologic

Soils Group

Percent

Impervious

Area

Impervious (ac)

Area Pervious

(ac)

Composite

C50

HSG B/C Soils (100/0 < 80/20) HSG B/C Soils (80/20 < 50/50)

HSG B/C

Ratio

HSG B/C Soils (0/100 < 25/75)

Assumptions for C Values

0.70-0.95

Composite

C100

Total Area

(ac)

Standard Form SF-1 . Time of Concentration

Project: CFLHD TO13 ND Auto Tour Route Computed: SE Date: 7/26/2022

System Name: Existing Hydrology Checked: AF Date: 8/12/2022

SUB-BASIN DATA INITIAL/OVERLAND FLOW TRAVEL TIME

(ti) (tt)

*see Tabl 3-3

Basin ID Description

Intercept

Coefficient (k)

B18 Offsite flows to 24" CMP 0.13 2 35.7 200 1966 1964 0.010 22 2130 1964 1796 0.079 0.3 3 12 34 34

B23 Offsite flows to 24" CMP 0.15 4 18.7 200 1964 1956 0.040 14 1192 1956 1786 0.143 0.3 4 5 19 19

B34 Offsite flows to 18" CMP 0.18 0 85.1 200 1958 1950 0.040 14 2455 1950 1800 0.061 0.3 3 16 30

B43 Offsite flows to 30" CMP 0.23 17 4.9 200 1842 1806 0.180 9 670 1806 1795 0.016 0.3 1 8 18

B50 Offsite flows to 30" CMP 0.19 2 97.0 200 1963 1961 0.010 22 3471 1961 1794 0.048 0.3 2 25 47 47

B52 Offsite flows to ditch at Sta. 50+75 - 52+25 Lt 0.62 83 0.2 100 1819 1813 0.060 8 224 1813 1808 0.022 0.3 2 2 11 11

B53 Offsite flows to ditch at Sta. 50+00 - 53+30 Rt 0.14 2 38.7 200 1965 1962 0.013 20 2545 1962 1811 0.059 0.3 3 17 37

B55

Offsite flows to Ditch Sta. 53+00 to 55+20 Rt /

18" CMP 0.27 24 3.5 200 1932 1925 0.035 15 1121 1925 1815 0.099 0.3 3 6 21

B63 Offsite flows to 24" CMP 0.14 3 10.3 200 1934 1926 0.040 14 821 1926 1817 0.133 0.3 4 4 18 18

B67 Offsite flows to 30" CMP 0.17 7 9.2 200 1954 1944 0.050 13 1456 1944 1810 0.092 0.3 3 8 21 21

B70 Offsite flows to ditch at Sta. 67+50 - 72+00 Rt 0.17 7 5.1 200 1930 1920 0.050 13 901 1920 1810 0.122 0.3 4 4 18 18

B72 Offsite flows to 2-30" CMP 0.16 5 65.2 200 1967 1964 0.015 19 2802 1964 1799 0.059 0.3 3 18 38 38

B84 Offsite flows to 30" CMP 0.21 15 18.8 200 1968 1966 0.010 22 1840 1966 1815 0.082 0.3 3 10 32 32

B87 Offsite flows to ditch at Sta. 83+50 85+50 Rt 0.18 9 6.2 200 1951 1942 0.045 14 896 1942 1829 0.126 0.3 4 4 18 18

B97 Offsite flows to 24" RCP 0.17 7 26.8 200 1968 1966 0.010 22 2308 1966 1796 0.074 0.3 3 14 35 35

B99 Offsite flows to 24" RCP 0.19 11 90.2 200 1965 1960 0.025 17 3337 1960 1792 0.050 0.3 2 24 40 40

B104 Offsite flows to 24" RCP 0.19 11 14.2 200 1931 1923 0.040 14 1950 1923 1815 0.055 0.3 2 13 28 28

Notes: HEC-22 Table 3-3. Intercept Coefficients for Velocity vs Slope English Unit Conversion

1. Overland Flow, ti = (0.933/(intensity^0.4))((n*L/sqrt(slope))^0.6) (HEC22, Section 3.2.2.3 / Equation 3-3) Land Cover/Flow Regime k

2. Travel Time, Tt = L/60V (HEC22, Section 3.2.2.3 / Equation 3-6) Forest with heavy ground litter; hay meadow (overland flow) 0.076 0.11324

3. Velocity, V = ku*k*Sp^0.5 (HEC22, Section 3.2.2.3 / Equation 3-4) Trash fallow or minimum tillage cultivation; contour or strip cropped; woodland (overland flow) 0.152 0.22648

4. Shallow Concentrated Flow Velocity, Vt = HEC22, Eqaution 3-4 V=KukSp^0.5 Short grass pasture (overland flow) 0.213 0.31737

5. k HEC22 Table 3-3 Cultivated straight row (overland flow) 0.274 0.40826

6. n HEC 22 Table 3-2 Nearly bare and untilled (overland flow); alluvial fans in western mountain regions 0.305 0.45445

6. Minimum Tc = 5 minutes Grassed waterway (shallow concentrated flow) 0.457 0.68093

Unpaved (shallow concentrated flow) 0.491 0.73159

Paved area (shallow concentrated flow); small upland gullies 0.619 0.92231

C5

Length

(ft)

Elevation

Start

Elevation

End

Slope

(ft/ft)

Percent

Impervious

FINAL Tc

(min)

Total

Area

(ac) ti

(min) Length (ft)

Elevation

Start

Elevation

End

So

(ft/ft) Velocity

Travel

Time Tt

(min) tc = ti + tt

(min)

Rational Analysis

Standard Form SF-2 . Storm Drainage System Design (Rational Method Procedure) Corridor / Design Package: CFLHD TO13 ND Auto Tour Route Computed: SE Date: 7/26/2022

System Name: Existing Hydrology Checked: AF Date: 8/12/2022

Design Storm: 2-yr

A R

E A

D

S

IG

N

(n a m e

A R

E A

A

C

R U

N O

F F

C O

E F

F t c

(M

IN

C .A

(A C

I

IN

H R

Q

(C

S

S U

M

C *A

(A C

I

(I N

H

R

Q

(C F

S

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

Offsite flows to 24" CMP B18 35.7 0.11 34 3.9 1.4 5.6

Offsite flows to 24" CMP B23 18.7 0.13 19 2.3 2.1 4.9

Offsite flows to 18" CMP B34 85.1 0.15 30 12.8 1.5 19.4

Offsite flows to 30" CMP B43 4.9 0.20 18 1.0 2.2 2.2

Offsite flows to 30" CMP B50 97.0 0.16 47 15.9 1.2 18.9 47 16.9 1.2 20.1 B55 to B53 to B50

Offsite flows to ditch at Sta. 50+75 - 52+25 Lt B52 0.2 0.60 11 0.1 2.8 0.3

Offsite flows to ditch at Sta. 50+00 - 53+30 Rt B53 38.7 0.11 37 4.4 1.4 6.1 37 5.26 1.4 7.3 B55 to B53 Offsite flows to Ditch Sta. 53+00 to 55+20 Rt /

18" CMP

B55 3.5 0.24 21 0.9 2.0 1.8

Offsite flows to 24" CMP B63 10.3 0.12 18 1.2 2.2 2.7

Offsite flows to 30" CMP B67 9.2 0.14 21 1.3 2.0 2.6 21 2.02 2.0 4.1 B70 to B67

Offsite flows to ditch at Sta. 67+50 - 72+00 Rt B70 5.1 0.14 18 0.7 2.2 1.6

Offsite flows to 2-30" CMP B72 65.2 0.13 38 8.6 1.4 11.8

Offsite flows to 30" CMP B84 18.8 0.19 32 3.6 1.5 5.3 32 4.5 1.5 6.7 B87 to B84

Offsite flows to ditch at Sta. 83+50 85+50 Rt B87 6.2 0.15 18 0.9 2.2 2.1

Offsite flows to 24" RCP B97 26.8 0.14 35 3.9 1.4 5.5

Offsite flows to 24" RCP B99 90.2 0.16 40 14.8 1.3 19.6

Offsite flows to 24" RCP B104 14.2 0.16 28 2.3 1.7 3.9

(1) Basin Description linked to C-Value Sheet (7) =Column 4 x Column 5

(2) Basin Design Point (8) Intensity from Noah 14 Atlas

(3) Enter the Basin Name from C Value Sheet (9) =Column 7 x Column 8

(4) Basin Area linked to C-Value Sheet (10) =Column 6 + Column 21

(5) Composite C linked to C-Value Sheet (11) Add the Basin Areas (7) to get the combined basin AC

(6) Time of Concentration linked to C-Value Sheet (12) =28.5*P/(10+Column 10)^0.786

(13) Sum of Qs

REMARKSLOCATION

D E

S

IG

N P

O

IN

T DIRECT RUNOFF TOTAL RUNOFF

Corridor / Design Package: CFLHD TO13 ND Auto Tour Route Computed: SE Date: 7/26/2022

System Name: Existing Hydrology Checked: AF Date: 8/12/2022

Design Storm: 10-yr

A R

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A R

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A

C

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N O

F F

C O

E F

C .A

(A C

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IN

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C *A

(A C

I

(I N

H

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Q

(C F

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(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

Offsite flows to 24" CMP B18 35.7 0.16 34 5.7 2.3 13.1

Offsite flows to 24" CMP B23 18.7 0.18 19 3.3 3.3 10.9

Offsite flows to 18" CMP B34 85.1 0.20 30 17.0 2.4 40.9

Offsite flows to 30" CMP B43 4.9 0.25 18 1.2 3.5 4.3

Offsite flows to 30" CMP B50 97.0 0.21 47 20.8 1.9 39.0 47 22.0 1.9 41.2 B55 to B53 to B50

Offsite flows to ditch at Sta. 50+75 - 52+25 Lt B52 0.2 0.65 11 0.1 4.4 0.6

Offsite flows to ditch at Sta. 50+00 - 53+30 Rt B53 38.7 0.16 37 6.3 2.2 13.8 37 7.37 2.2 16.1 B55 to B53

Offsite flows to Ditch Sta. 53+00 to 55+20 Rt / 18"

CMP

B55 3.5 0.29 21 1.0 3.2 3.4

Offsite flows to 24" CMP B63 10.3 0.17 18 1.7 3.5 6.0

Offsite flows to 30" CMP B67 9.2 0.19 21 1.8 3.2 5.6 21 2.74 3.2 8.7 B70 to B67

Offsite flows to ditch at Sta. 67+50 - 72+00 Rt B70 5.1 0.19 18 1.0 3.5 3.4

Offsite flows to 2-30" CMP B72 65.2 0.18 38 11.9 2.2 25.7

Offsite flows to 30" CMP B84 18.8 0.24 32 4.5 2.3 10.6 32 5.8 2.3 13.5 B87 to B84

Offsite flows to ditch at Sta. 83+50 85+50 Rt B87 6.2 0.20 18 1.3 3.5 4.3

Offsite flows to 24" RCP B97 26.8 0.19 35 5.2 2.2 11.7

Offsite flows to 24" RCP B99 90.2 0.21 40 19.4 2.1 40.4

Offsite flows to 24" RCP B104 14.2 0.21 28 3.1 2.6 8.0

(1) Basin Description linked to C-Value Sheet (7) =Column 4 x Column 5

(2) Basin Design Point (8) Intensity from Noah 14 Atlas

(3) Enter the Basin Name from C Value Sheet (9) =Column 7 x Column 8

(4) Basin Area linked to C-Value Sheet (10) =Column 6 + Column 21

(5) Composite C linked to C-Value Sheet (11) Add the Basin Areas (7) to get the combined basin AC

(6) Time of Concentration linked to C-Value Sheet (12) =28.5*P/(10+Column 10)^0.786

(13) Sum of Qs

REMARKSLOCATION

D E

S

IG

N P

O

IN

Corridor / Design Package: CFLHD TO13 ND Auto Tour Route Computed: SE Date: 7/26/2022

System Name: Existing Hydrology Checked: AF Date: 8/12/2022

Design Storm: 25-yr

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(A C

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C *A

(A C

I

(I N

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Q

(C F

S

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

Offsite flows to 24" CMP B18 35.7 0.21 34 7.5 2.8 21.0

Offsite flows to 24" CMP B23 18.7 0.23 19 4.2 4.1 17.1

Offsite flows to 18" CMP B34 85.1 0.25 30 21.3 2.9 62.8

Offsite flows to 30" CMP B43 4.9 0.30 18 1.5 4.3 6.3

Offsite flows to 30" CMP B50 97.0 0.26 47 25.6 2.3 58.8 47 27.0 2.3 62.0 B55 to B53 to B50

Offsite flows to ditch at Sta. 50+75 - 52+25 Lt B52 0.2 0.70 11 0.1 5.4 0.8

Offsite flows to ditch at Sta. 50+00 - 53+30 Rt B53

38.7 0.21 37 8.3

2.7

22.2 37 9.48 2.7 25.5

B55 to B53

Offsite flows to Ditch Sta. 53+00 to 55+20 Rt /

18" CMP

B55

3.5 0.34 21 1.2

3.9

4.8

Offsite flows to 24" CMP B63 10.3 0.22 18 2.3 4.2 9.5

Offsite flows to 30" CMP B67 9.2 0.24 21 2.2 3.9 8.7 21 3.45 3.9 13.4 B70 to B67

Offsite flows to ditch at Sta. 67+50 - 72+00 Rt B70 5.1 0.24 18 1.2 4.3 5.2

Offsite flows to 2-30" CMP B72 65.2 0.23 38 15.1 2.7 40.3

Offsite flows to 30" CMP B84 18.8 0.29 32 5.4 2.9 15.7 32 7.0 2.9 20.2 B87 to B84

Offsite flows to ditch at Sta. 83+50 85+50 Rt B87 6.2 0.25 18 1.6 4.2 6.6

Offsite flows to 24" RCP B97 26.8 0.24 35 6.6 2.8 18.0

Offsite flows to 24" RCP B99 90.2 0.26 40 23.9 2.6 61.0

Offsite flows to 24" RCP B104 14.2 0.26 28 3.8 3.2 12.1

(1) Basin Description linked to C-Value Sheet (7) =Column 4 x Column 5

(2) Basin Design Point (8) Intensity from Noah 14 Atlas

(3) Enter the Basin Name from C Value Sheet (9) =Column 7 x Column 8

(4) Basin Area linked to C-Value Sheet (10) =Column 6 + Column 21

(5) Composite C linked to C-Value Sheet (11) Add the Basin Areas (7) to get the combined basin AC

(6) Time of Concentration linked to C-Value Sheet (12) =28.5*P/(10+Column 10)^0.786

(13) Sum of Qs

REMARKSLOCATION

D E

S

IG

N P

O

IN

Corridor / Design Package: CFLHD TO13 ND Auto Tour Route Computed: SE Date: 7/26/2022

System Name: Existing Hydrology Checked: AF Date: 8/12/2022

Design Storm: 50-yr

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(A C

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(I N

H

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Q

(C F

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(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

Offsite flows to 24" CMP B18 35.7 0.26 34 9.3 3.2 29.7

Offsite flows to 24" CMP B23 18.7 0.28 19 5.1 4.6 23.9

Offsite flows to 18" CMP B34 85.1 0.30 30 25.6 3.4 85.8

Offsite flows to 30" CMP B43 4.9 0.35 18 1.7 4.9 8.3

Offsite flows to 30" CMP B50 97.0 0.31 47 30.5 2.6 80.0 47 32.0 2.6 84.0 B55 to B53 to B50

Offsite flows to ditch at Sta. 50+75 - 52+25 Lt B52 0.2 0.75 11 0.2 6.2 0.9

Offsite flows to ditch at Sta. 50+00 - 53+30 Rt B53 38.7 0.26 37 10.2 3.1 31.1 37 11.59 3.1 35.4 B55 to B53Offsite flows to Ditch Sta. 53+00 to 55+20 Rt / 18"

CMP B55 3.5 0.39 21 1.4 4.5 6.3

Offsite flows to 24" CMP B63 10.3 0.27 18 2.8 4.8 13.4

Offsite flows to 30" CMP B67 9.2 0.29 21 2.7 4.4 12.0 21 4.17 4.4 18.5 B70 to B67

Offsite flows to ditch at Sta. 67+50 - 72+00 Rt B70 5.1 0.29 18 1.5 4.9 7.2

Offsite flows to 2-30" CMP B72 65.2 0.28 38 18.4 3.0 55.7

Offsite flows to 30" CMP B84 18.8 0.34 32 6.4 3.3 20.9 32 8.3 3.3 27.1 B87 to B84

Offsite flows to ditch at Sta. 83+50 85+50 Rt B87 6.2 0.30 18 1.9 4.8 9.1

Offsite flows to 24" RCP B97 26.8 0.29 35 7.9 3.1 24.7

Offsite flows to 24" RCP B99 90.2 0.31 40 28.4 2.9 82.7

Offsite flows to 24" RCP B104 14.2 0.31 28 4.5 3.7 16.3

(1) Basin Description linked to C-Value Sheet (7) =Column 4 x Column 5

(2) Basin Design Point (8) Intensity from Noah 14 Atlas

(3) Enter the Basin Name from C Value Sheet (9) =Column 7 x Column 8

(4) Basin Area linked to C-Value Sheet (10) =Column 6 + Column 21

(5) Composite C linked to C-Value Sheet (11) Add the Basin Areas (7) to get the combined basin AC

(6) Time of Concentration linked to C-Value Sheet (12) =28.5*P/(10+Column 10)^0.786

(13) Sum of Qs

REMARKSLOCATION

D E

S

IG

N P

O

IN

Corridor / Design Package: CFLHD TO13 ND Auto Tour Route Computed: SE Date: 7/26/2022

System Name: Existing Hydrology Checked: AF Date: 8/12/2022

Design Storm: 100-yr

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A R

E A

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F F

C O

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C .A

(A C

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IN

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C *A

(A C

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(I N

H

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Q

(C F

S

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

Offsite flows to 24" CMP B18 35.7 0.31 34 11.1 3.6 39.6

Offsite flows to 24" CMP B23 18.7 0.33 19 6.1 5.2 31.6

Offsite flows to 18" CMP B34 85.1 0.35 30 29.8 3.8 112.2

Offsite flows to 30" CMP B43 4.9 0.40 18 2.0 5.5 10.7

Offsite flows to 30" CMP B50 97.0 0.36 47 35.3 2.9 104.0 47 37.1 2.9 109.1 B55 to B53 to B50

Offsite flows to ditch at Sta. 50+75 -

52+25 Lt B52 0.2 0.80 11 0.2 6.9 1.1

Offsite flows to ditch at Sta. 50+00 -

53+30 Rt B53 38.7 0.31 37 12.1 3.4 41.7 37 13.70 3.4 47.1 B55 to B53

Offsite flows to Ditch Sta. 53+00 to

55+20 Rt / 18" CMP B55 3.5 0.44 21 1.6 5.0 7.9

Offsite flows to 24" CMP B63 10.3 0.32 18 3.3 5.4 17.7

Offsite flows to 30" CMP B67 9.2 0.34 21 3.2 5.0 15.7 21 4.88 5.0 24.3 B70 to B67Offsite flows to ditch at Sta. 67+50 -

72+00 Rt B70 5.1 0.34 18 1.7…