Bridge_#2001_Final_Hydraulic_Report.pdf

9175 West Black Eagle Drive Boise Idaho 83709 Telephone: 208.900.9049 Facsimile: 503.223.2701

DATE: November 14, 2024

TO: Chris Dayley – Ada County Highway District

Dale Kuperus – Ada County Highway District

FROM: Parker Jones, P.E.

Spencer Savage, P.E.

SUBJECT: Final Hydraulic Analysis – Middleton Canal Crossing at Munger Rd. Bridge #2001

PROJECT: ACHD Project No. 224008

Munger Rd. Bridges #1005 & #2001 Phase 2

CC: Ali Rigeb, P.E.

1. PROJECT BACKGROUND

Ada County Highway District (ACHD) is proposing to reconstruct a segment of Munger Road in Star, Idaho and the project includes replacement of the existing hydraulic crossing over Middleton Canal. The existing crossing

(Bridge #2001) was constructed in 1965 as a single-span prestressed concrete tee beam bridge (ACHD 2021) and conveys irrigation water beneath Munger Road. Inspection reports and survey data indicate the bridge is

28-feet wide with a hydraulic opening of 25-feet and a low-chord elevation of 2460.34-feet. The bridge will be replaced with a box culvert and be designed to accommodate the future widening of Munger Road. Concept designs for the future widening of Munger Road across Middleton Canal indicate the new box culvert needs to accommodate a minimum curb to curb width of 71-feet for additional travel lanes, bike lanes, and pedestrian facilities. This technical memorandum (memo) summarizes the hydrologic and hydraulic analysis for the hydraulic crossing.

2. DESIGN CRITERIA

This project falls under ACHD’s jurisdiction and is subject to ACHD’s design criteria. Per ACHD standards, culverts other than pipes and that have a span greater than 60 inches shall be designed following bridge requirements. As such, the hydraulic design and analysis of the proposed box culvert has been performed in accordance with Section 3004.2 of the ACHD Policy Manual. The design standards are summarized as follows:

◼ ACHD Policy Manual Section 3004.2.2.a.6 – Hydraulic Requirements

− Bridges over controlled waterways shall meet minimum flow capacity and freeboard requirements of the regulating authorities, including irrigation/drainage companies/districts and ACHD.

− ACHD requires a minimum freeboard of 1-foot. Per Section 3004.2.1.c, freeboard is defined as the clearance between the ceiling of the bridge/culvert and the design water surface elevation.

o For this project, ceiling of the bridge/culvert is based on the lowest point of the crossing structure.

◼ ACHD Policy Manual Section 3004.2.2.a19 – Scour Control

− Bridges over controlled ditches and canals shall:

o Be designed with headwalls, wingwalls, aprons, and cutoff walls;

o Be designed with reinforced concrete floors; and, DATE: November 14, 2024 FROM: Parker Jones, P.E.

TO: Ada County Highway District SUBJECT: Final Hydraulic Analysis, Bridge

#2001 o If adjacent channel is unlined, then angular riprap shall be placed on non-woven geotextile fabric at the entrance and exit for a minimum distance equal to the channel width.

◼ ACHD Policy Manual Section 3006.5 – Riprap

− Riprap will be sized to resist movement at the designed maximum flows.

− Minimum size (D50) will be 12-inches in diameter, layered to a minimum thickness of 2 times D50.

− Riprap shall be angular having at least 2 broken or jagged faces.

3. STAKEHOLDER COORDINATION

Middleton Canal is operated and maintained by Middleton Mill Ditch Company (MMDC). Coordination with

MMDC occurred in June 2024 and summary notes from those meetings are included in Attachment A. The purpose of the meetings was to discuss existing issues, summarize proposed improvements, obtain concurrence on hydraulic design criteria, and identify flow rates at the crossing. MMDC noted that the existing crossing is likely oversized and a smaller structure would be acceptable as long as the proposed design satisfies hydraulic design criteria. Additionally, MMDC provided concurrence on the design criteria listed in Section 2 of this memo, but noted recurring issues with debris getting caught on riprap aprons. MMDC asked that riprap aprons be embedded into the channel to minimize the risk of debris getting caught and riprap not to be placed within the barrel of the culvert. Lastly, MMDC provided information on normal and maximum flow rates and details are provided in Section 4 of this memo.

4. HYDROLOGY

Flow rates in Middleton Canal are managed and vary based on irrigation demands in the surrounding area but it does continue to run year-round. During coordination meetings, MMDC stated they have a water right for approximately 200 cubic feet per second (cfs) that can be conveyed through the canal. However, MMDC noted that 200 cfs is the maximum flow in the canal and normal flow rates are approximately 180 cfs. MMDC also noted a similar project was completed by ACHD upstream of Munger Road at Floating Feather Road and similar flow rates were used for that project. Table 1 summarizes the canal flows as communicated by MMDC and the maximum flow rate of 200 cfs was used for designing the proposed crossing.

TABLE 1 - MIDDLETON CANAL FLOW RATES

Middleton Canal Flows

Normal Flow 180 cfs

Maximum Flow (selected for design) 200 cfs

5. HYDRAULICS

The hydraulic analysis of the Middleton Canal crossing was performed using a 1-dimensional (1D) HEC-RAS hydraulic model (version 6.4.1). An existing conditions model was developed to establish baseline hydraulic conditions for Middleton Canal. Once complete, a proposed conditions model was developed to evaluate structure sizes and confirm hydraulic design criteria will be satisfied. The following sections provide a summary of survey data, hydraulic model development, existing and proposed structures, and hydraulic modeling results.

5.1. TERRAIN DATA & MODEL DEVELOPMENT

A topographic field survey was performed by DEA in January and February of 2024 to collect site-specific data for the hydraulic analysis and project design. Site-specific data included terrain elevations, channel geometry, channel bathymetry, roadway elevations, and structure dimensions and elevations. For the hydraulic analysis, the survey limits began approximately 115-feet downstream of the crossing and ended approximately 450-feet upstream of the crossing. The diversion structure located at the upstream model boundary was neglected to maintain conservative flow rates. A summary of the survey data is provided in Table 2.

TABLE 2 – SUMMARY OF SURVEY DATA

Coordinate System / Datum Units

NAD83 2011 Idaho State Plane West Zone US Survey Feet

North American Vertical Datum 1988 (NAVD88) – Geoid 18 US Survey Feet

Terrain data from the field survey was processed and used to develop the hydraulic model. A profile baseline

(channel centerline) was established using thalweg contours and cross sections were spaced along the centerline at approximately 30-foot intervals with bounding cross sections placed immediately upstream and downstream of the structure. Cross-sectional geometry was taken from terrain data to represent the cross-sectional flow area through the channel. Manning’s roughness values (n-values) of 0.035 and 0.05 were assigned for the channel and overbanks, respectively, to represent an earthen channel and vegetated overbanks. These values were selected based on site photographs (see Attachment F) and previous hydraulic studies at an adjacent crossing. Bank stations at each cross section were established using grade breaks, channel geometry, and horizontal variations in roughness values. The downstream boundary condition was set to normal depth with a slope of 0.002 feet/feet to represent the average slope of the canal through the modeling domain. All model input parameters remained the same between existing and proposed conditions except for bounding cross sections and structure data. Bounding cross sections in the proposed conditions model were removed due to the increased length of the proposed structure. Details on existing and proposed structures are provided in Section 5.2 of this memo.

5.2. EXISTING & PROPOSED STRUCTURES

Geometric data for the existing structure was included in the existing conditions model. The existing structure was modeled as a single span bridge with a hydraulic opening (span) of 25-feet, a length of 28-feet, and a low-chord elevation of 2460.34-feet. The bridge clear-spans the canal and no overbank flow or roadway overtopping occurs. As such, the bridge was modeled assuming negligible headloss due to expansion and contraction and no ineffective flow areas. Table 3 provides a summary of the existing structure dimensions as modeled in HEC-RAS.

TABLE 3 - EXISTING STRUCTURE DIMENSIONS

Structure Type Low Chord (ft) Span (ft) Rise (ft) Length (ft)

Single Span Bridge 2460.34 25.0 n/a 28.0

The proposed structure will be a reinforced concrete box culvert and multiple sizes were evaluated to satisfy hydraulic design criteria. The geometry of the canal was considered when evaluating box culvert sizes. The existing canal is shallow with a trapezoidal shape. The average bottom width is 12-feet with a depth of approximately 3-feet from top of bank to canal bottom. Based on this, a span of 16-feet and a rise of 4.5-feet with flared wingwalls was selected as the preferred configuration for the box culvert. The box culvert will have a length of 80-feet to accommodate future widening on Munger road and a slope of 0.27 percent. The situation and layout drawings are provided in Attachment B. The 16-feet span will reduce the structure size when compared to the existing bridge, will be slightly oversized when compared to the canal bottom width, and the flared wingwalls will provide a smooth flow transition that minimizes ineffective flow areas. Additionally, a maximum rise of 4.5-feet is preferred because it will slightly raise the low-chord to 2460.50-feet while minimizing profile grade changes along Munger Road. Table 4 provides a summary of the proposed structure dimensions as modeled in HEC-RAS.

TABLE 4 - PROPOSED STRUCTURE DIMENSIONS

Structure Type Low Chord (ft) Span (ft) Rise (ft) Length (ft)

Reinforced Concrete Box Culvert 2460.50 16.0 4.5 80.0

5.3. MODLEING RESULTS

Hydraulic modeling results for existing and proposed conditions were reviewed for the design flow of 200 cfs. A summary of the modeling results is provided in Table 5 and HEC-RAS output files for existing and proposed conditions are provided in Attachment C and D, respectively. Water surface elevations were reviewed at two locations including the upstream face of respective structures and at cross-section 164, which is located immediately upstream of the proposed crossing. Both locations were reviewed to verify the proposed design will provide sufficient freeboard. As shown in Table 5, the 16-foot by 4.5-foot (span by rise) box culvert will provide 1.40 feet of freeboard at the upstream face of the culvert, which will satisfy the minimum 1-foot freeboard design requirement.

TABLE 5 – SUMMARY OF HYDRAULIC MODEL RESULTS

Scenario Design Flow

(cfs)

Low-Chord Elev.

(ft)

WSEL @ Structure

(ft)

WSEL Upstream*

(ft)

Freeboard**

(ft)

Existing 200 2460.34 2459.24 2459.37 1.10

Proposed 200 2460.50 2459.10 2459.32 1.40

*Based on cross-section 164, taken immediately upstream of proposed crossing

**Based on WSEL at upstream face of respective structure

6. SCOUR CONTROL & RIPRAP

Scour control measures will be implemented following ACHD Policy Manual Section 3004.2.2.a.19 and Section

3006.5. ACHD requires the channel to be lined with angular riprap upstream and downstream of the crossing for a distance that equals the channel width. The channel has an average width of approximately 20-feet from top of bank to top of bank around the project area. Therefore, the riprap aprons will line the channel bottom and side slopes and extend 20-feet from the inlet and outlet of the box culvert. ACHD also requires riprap to have a minimum median diameter (D50) of 1-feet with a blanket thickness that is twice the D50. The hydraulic model results and guidance from Federal Highway Administration’s Hydraulic Engineering Circular No. 14

(FHWA 2006) were used to calculate the riprap size and verify whether the minimum diameter of 1-feet is sufficient. Based on the hydraulic model results, the calculated riprap size is 0.17 feet and the calculation is provided in Attachment E. Therefore, the riprap aprons will have a D50 of 1-feet, a blanket thickness of 2-feet, and be placed on top of non-woven geotextile fabric. The scour control, cutoff walls, and riprap aprons are shown on the design drawings in Attachment B.

7. REFERENCES

Ada County Highway District (ACHD). 2021. Over 20 Bridge Inspection Report: 2001 Munger Over Middleton

Canal. Inspection date of 11/04/2021.

Federal Highway Administration (FHWA). 2006. Hydraulic Engineering Circular No. 14 – Hydraulic Design of

Energy Dissipators for Culverts and Channels, Third Edition.

United States Army Corps of Engineers (USACE). 2023. Hydrologic Engineering Center River Analysis System

(HEC-RAS), Version 6.4.1.

8. ATTACHMENTS / ENCLOSURES

A. Correspondence

B. Design Drawings – Situation & Layout

C. HEC-RAS Results – Existing Conditions Model

D. HEC-RAS Results – Proposed Conditions Model

E. Riprap Sizing Calculation

F. Site Photos

Attachment A

ATTACHMENT A.

CORRESPONDENCE

9175 West Black Eagle Drive Boise Idaho 83709 Telephone: 208.900.9049 Facsimile: 503.223.2701

DATE: May 31, 2024

TO: File – Stakeholder Coordination

DEA Boise

FROM: Spencer Savage, PE

SUBJECT: Phone Conversation – Allen Funkhauser

PROJECT: ACHD Project No. 224008 Munger Rd Bridges #1005 and #2001 Phase 2

DEA Project No. ADAX00HD0007

CC: DEA Project Task Leads

Phone conversation occurred on May 31, 2024 with Allen Funkhauser from Middleton Mill Ditch Company /

Drainage District 2 (MMDC/DD2). Allen’s contact information is provided below. Allen noted that he is getting close to retirement, but he will be the main contact/representative for MMDC/DD2. He is aware that DEA will reach out in the coming weeks to discuss additional items.

• Allen Funkhauser – Manager o Phone: 208-571-3804 o Email: allenfun50@hotmail.com

The phone conversation focused on hydraulic crossings #1005 and #2001. There was limited discussion on

McHenry Flume and the minor supply/lateral just north of crossing #2001. Brief summary provided below.

• Crossing #1005 (North Crossing – Drain 10) o Allen confirmed this is Drain 10 and not Dry Creek Canal.

o Flow rates in this drain are highly variable, especially during irrigation season. Multiple irrigators spill into and pull from the drain. Therefore, normal and maximum flow rates are unknown.

o Allen noted that minimum flow during winter is ~30 cfs.

o MMDC/DD2 can shift flow between Drain 10 and Middleton Canal (see Figure 2 below). Check structures are located north of Star Rd/Floating Feather intersection on respective facilities with a feeder that connects Drain 10 to Middleton Canal. If needed, Allen said they can shift flow during construction.

o Existing box culvert is undersized. WSELs exceed low chord of box culvert on a regular basis.

Allen noted that Munger Road has been built-up over the years at this crossing.

o Allen said WSELs have never reached the low chord of the steel beam that supports the aerial pipe on the east side of Munger Road. He thought using the beam low chord elevation as the new low chord elevation for Munger Road would be good.

o Allen said a wider structure with a higher low chord elevation is desired since flow rates are variable.

mailto:allenfun50@hotmail.com

DATE: May 31, 2024 FROM: Spencer Savage, PE

TO: File – Stakeholder Coordination SUBJECT: Phone Conversation – Allen

Funkhauser

• Crossing #2001 (South Crossing – Middleton Canal) o Allen confirmed this is Middleton Canal.

o We discussed the Floating Feather bridge project (just upstream of Munger crossing) and the hydraulic analysis performed by Horrocks. Flow rates used for that project were:

▪ Normal Flow: 180 cfs

▪ Maximum Flow: 200 cfs o Allen confirmed they have a water right for ~200 cfs, but flow within Middleton Canal rarely gets that high. He agreed that the using the design flows from Floating Feather bridge project is appropriate for this crossing.

o Allen acknowledged the existing bridge is wider than it needs to be and agreed that the proposed crossing design can have a reduced hydraulic opening.

FIGURE 1. OVERVIEW OF FACILITIES DISCUSSED.

DATE: May 31, 2024 FROM: Spencer Savage, PE

TO: File – Stakeholder Coordination SUBJECT: Phone Conversation – Allen

Funkhauser

FIGURE 2. LOCATIONS WHERE MMDC/DD2 CAN SHIFT FLOW BETWEEN DRAIN 10 AND MIDDLETON

CANAL.

Attachments/Enclosures: None

File Path: P:\A\ADAX00HD0007\0300COM\0360Stakeholders\Middleton Mill Ditch Co\20240531_MiddletonMillDitch_PhoneConversationSummary.docx

9175 West Black Eagle Drive Boise Idaho 83709 Telephone: 208.900.9049 Facsimile: 503.223.2701

DATE: June 13, 2024

TO: File – Stakeholder Coordination

DEA Boise

FROM: Ali Rigeb, PE

SUBJECT: Phone Conversation - Allen Funkhauser (Middleton Mill), Chris Dayley (ACHD), Spencer

Savage (DEA), Ali Rigeb (DEA)

PROJECT: ACHD Project No. 224008

Munger Rd Bridges #1005 and #2001 Phase 2

DEA Project No. ADAX00HD0009

CC: DEA Project Task Leads

Phone conversation occurred on June 13, 2024 with Allen Funkhauser from Middleton Mill Ditch Company /

Drainage District 2 (MMDC/DD2) and Chris Dayley, ACHD PM.

The phone conversation focused on hydraulic crossings #1005 and #2001. Brief summary provided below.

• Crossing #1005 (North Crossing – Drain 10) o Allen prefers a larger hydraulic opening and a raised low chord

▪ Doesn’t think water has ever gotten to the bottom of the existing upstream steel beam

▪ Ali mentioned new culvert will but up to ROW so that gap between the aerial pipe and end of culvert will be ~4’ (as opposed to the existing ~12’). Allen doesn’t think debris collection should be an issue since we are making the hydraulic opening wider and taller

▪ Allen thinks the target high water shown below is adequate for design:

o Spencer will refine hydro model to see what Q is obtained using the target high water mark or bottom of steel beam as the low chord

DATE: June 13, 2024 FROM: Ali Rigeb, PE

TO: File – Stakeholder Coordination SUBJECT: Phone Conversation - Allen

Funkhauser (Middleton Mill), Chris

Dayley (ACHD), Spencer Savage (DEA), Ali Rigeb (DEA) o Allen agrees 200cfs-220cfs is plenty adequate for Drain 10 design o Storm water into Canal - Allen mentioned the storm drain just downstream of the existing structure gets very little water, if any. He has no problem with us tying into it and draining into the canal as along as the existing sand/grease traps can take the new flow.

▪ Allen noted that they will accept stormwater runoff as long as it's treated in accordance with DEQ/ACHD requirements.

• Crossing #2001 (South Crossing – Middleton Canal) o Allen prefers reduced hydraulic opening o Agreed on 200cfs

• In General o Allen confirmed he is OK with a stiffleg or a box culvert at either location o Allen mentioned both culverts downstream of Munger Road along Drain 10 are box culverts (1 at CanAda Rd) o Allen is amenable to the cut-off wall/riprap apron inlet and outlet detail that was used on Black

Cat and Reutzel

▪ DON’T embed culvert invert below streambed and add riprap full length of culvert -good way to introduce maintenance issues

▪ Riprap aprons at the inlet and outlet should be flush with streambed elevation

Attachment B

ATTACHMENT B.

DESIGN DRAWINGS – SITUATION & LAYOUT

Wing Wall (Typ.)

Loose Riprap (Typ.)Invert Elev. = 2456.00 Invert Elev. = 2456.22

5" Existing Conduit (To Be Removed)

10" Existing Water (5' Depth Assumed)

℄ N Munger Road

Apron (Typ.)

Top Of Headwall (Typ.)

Bike Railing (Typ.)

Cutoff Wall (Typ.)

High Water Elev. 2459.10

Middleton Canal Flow Direction

Finished Grade See Roadway Typical Sections2" Concrete Sand

(See Note 2)

4" Existing Gas Line (3' Depth Assumed)

X" Fiber (3' Depth Assumed, Location Approx. And Size Unknown)

InletOutlet

8" Existing Pressure Sewer (5' Depth Assumed)

T T

T T

T T

T

T T

T T

T T

Sew

Sew

Sew

Sew

Sew

Sew

W

W

W

W

W

W

W

W

W

W

W

W

W

W

W

O P

O P

O P

O P

O P

O P

O P

O P

O P

O P

O P

O P

O P

O P

O P

G

G

G

G

G

G

G

G

G

G

G

G

G

G

G

P/L

P/L

P/L

P/L

P/L

P/L

P/L

P/L

P/L

P/L

P/L

Revisions:

Design By: A. Rigeb Date: 01/03/2025 Date: 01/03/2025Drawn By: C. Schreiner

S I G N A T U R E S

D E T A I L T I T L E

Situation & Layout

S1Sheet Ada County Highway District Project Number: 2240083775 Adams Street, Garden City, Idaho, 83714 www.achdidaho.org Project Name: MUNGER ROAD BRIDGE #2001

9175 W Black Eagle Dr Boise, ID 83709

Phone: 208.900.9049

T Y P I C A L S E C T I O N Scale: 1/2" = 1'-0"

L O N G I T U D I N A L S E C T I O N Scale: 1" = 5'-0"

Concrete Waterproof System. Extend To

Bottom Of Culvert (Typ.)

2'-0" (Typ.)

M in

16'-0"

P L A N Scale: 1" = 5'-0"

N

M U

N G

E R

R O

A D

N 01°00'46"E

Existing R/W Existing R/W

Existing Easement

80'-0" Out To-Out Proposed 16'x4.5' Precast Box Culvert (See Note 3)

Survey Control Line

5" Existing Conduit (To Be Removed)

8" Existing Pressure Sewer

10" Existing Water

MiddletonCanal

Existing Overhead Power

12'-0"

Travel Lane

12'-0"

Travel Lane

3'-0"

Gravel

Shoulder

C le ar S77°59'14"E

End Bridge = ℄ Munger Road Sta. 3+70.63 39.27' Lt.

Begin Bridge = ℄ Munger Road

Sta. 3+55.37 39.27' Rt.

℄ Munger Road Sta. 3+63.00

Existing Bridge #2001 (To Be Removed)

Inlet

Outlet

Loose Riprap (Typ.)

80'-0"

1'-0" (Typ.)

1.40' Min.

Freeboard

L E G E N D

Headwall (Typ.)

101°0'0"'

℄ Bridge

Approx. Existing Ground

3'-0"

Gravel

Shoulder

9" Chamfer (Typ.)

Apron (Typ.)

Cutoff Wall (Typ.)

Bike Railing (Typ.)

Wall 4

2" Concrete Sand (See Note 2)

Crushed Aggregate For Base Type 1 (Typ. Under Wing Walls And Culvert)

Proposed Top of Bank

(T yp

2" Concrete Sand (See Note 2)

Proposed Permanent Easement

N O T E

1. Utility Information Shown Is Based On Available

Information After Contacting Each Utility.

2. Concrete Sand To Be Incidental to Concrete

Waterproofing Bid Item.

3. Use Chromium Reinforcement in Precast Box

Culvert. See Sheet S2 for Details.

20'-0" Min. (Typ.)

4" Existing Gas Line

M in

M in

9" Min.

(Typ.)

Proposed Temporary Easement

App-1 (See Roadway Plans)

Existing Top Of Bank (Typ.)

(Shown At CL Bridge)

Wall 3

Wall 1

Wall 2

Proposed Permanent Easment

Existing X" Fiber (Approx. Location)

Attachment C

ATTACHMENT C.

HEC-RAS RESULTS

EXISTING CONDITIONS MODEL

HEC-RAS Plan: Existing River: Middleton Canal Reach: Munger Crossing

Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl Hydr Depth

(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (ft)

Munger Crossing 8 Normal Flow 180.00 2455.66 2458.77 2457.52 2458.95 0.002003 3.44 53.83 24.66 0.38 2.18

Munger Crossing 8 Max Flow 200.00 2455.66 2458.93 2457.63 2459.13 0.002002 3.58 57.92 25.73 0.38 2.25

Munger Crossing 45 Normal Flow 180.00 2456.00 2458.82 2459.05 0.002734 3.90 47.04 21.49 0.44 2.19

Munger Crossing 45 Max Flow 200.00 2456.00 2458.98 2459.23 0.002731 4.07 50.54 22.50 0.44 2.25

Munger Crossing 83 Normal Flow 180.00 2456.00 2458.94 2459.16 0.002599 3.76 49.12 23.61 0.43 2.08

Munger Crossing 83 Max Flow 200.00 2456.00 2459.10 2459.33 0.002561 3.90 53.01 24.32 0.43 2.18

Munger Crossing 107 Normal Flow 180.00 2456.28 2459.02 2459.22 0.002519 3.59 51.33 25.56 0.42 2.01

Munger Crossing 107 Max Flow 200.00 2456.28 2459.19 2459.40 0.002449 3.71 55.59 26.24 0.42 2.12

Munger Crossing 142 Bridge

Munger Crossing 151 Normal Flow 180.00 2456.37 2459.12 2458.22 2459.37 0.003199 3.96 46.45 23.53 0.47 1.97

Munger Crossing 151 Max Flow 200.00 2456.37 2459.28 2458.33 2459.54 0.003136 4.10 50.23 24.94 0.47 2.01

Munger Crossing 164 Normal Flow 180.00 2456.22 2459.21 2459.40 0.002292 3.57 51.65 27.40 0.40 1.89

Munger Crossing 164 Max Flow 200.00 2456.22 2459.37 2459.58 0.002270 3.70 57.32 45.50 0.41 1.26

Munger Crossing 195 Normal Flow 180.00 2456.38 2459.31 2459.47 0.001905 3.22 59.74 41.75 0.37 1.43

Munger Crossing 195 Max Flow 200.00 2456.38 2459.48 2459.65 0.001827 3.30 67.38 47.81 0.36 1.41

Munger Crossing 232 Normal Flow 180.00 2456.16 2459.37 2459.55 0.002042 3.48 55.65 35.46 0.38 1.57

Munger Crossing 232 Max Flow 200.00 2456.16 2459.53 2459.73 0.002014 3.60 61.83 41.14 0.38 1.50

0 50 100 150 200 250

MungerRd_MiddletonCanal Plan: Existing 6/25/2024

Main Channel Distance (ft)

E le va tio n (f t)

Legend

EG Max Flow

EG Normal Flow

WS Max Flow

WS Normal Flow

Ground

Middleton Canal Munger Crossing

0 20 40 60 80 100

MungerRd_MiddletonCanal Plan: Existing 6/25/2024

RS = 232

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

Bank Sta

.05 .035 .05

0 10 20 30 40 50 60 70

MungerRd_MiddletonCanal Plan: Existing 6/25/2024

RS = 195

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

0 10 20 30 40 50 60 70 80

MungerRd_MiddletonCanal Plan: Existing 6/25/2024

RS = 164

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Existing 6/25/2024

RS = 151

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Existing 6/25/2024 RS = 142 BR Existing structure is a 28 ft long single span bridge with a hyd

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Existing 6/25/2024

RS = 107

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Existing 6/25/2024

RS = 83

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Existing 6/25/2024

RS = 45

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Existing 6/25/2024

RS = 8

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

Attachment D

ATTACHMENT D.

HEC-RAS RESULTS

PROPOSED CONDITIONS MODEL

HEC-RAS Plan: Proposed River: Middleton Canal Reach: Munger Crossing

Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl Hydr Depth

(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (ft)

Munger Crossing 8 Normal Flow 180.00 2455.66 2458.77 2457.52 2458.95 0.002003 3.44 53.83 24.66 0.38 2.18

Munger Crossing 8 Max Flow 200.00 2455.66 2458.93 2457.63 2459.13 0.002002 3.58 57.92 25.73 0.38 2.25

Munger Crossing 45 Normal Flow 180.00 2456.00 2458.82 2459.05 0.002734 3.90 47.04 21.49 0.44 2.19

Munger Crossing 45 Max Flow 200.00 2456.00 2458.98 2459.23 0.002731 4.07 50.54 22.50 0.44 2.25

Munger Crossing 83 Normal Flow 180.00 2456.00 2458.94 2459.16 0.002599 3.76 49.12 23.61 0.43 2.08

Munger Crossing 83 Max Flow 200.00 2456.00 2459.10 2459.33 0.002561 3.90 53.01 24.32 0.43 2.18

Munger Crossing 159.7 Culvert

Munger Crossing 164 Normal Flow 180.00 2456.22 2459.12 2458.07 2459.34 0.002580 3.70 49.58 24.05 0.43 2.06

Munger Crossing 164 Max Flow 200.00 2456.22 2459.32 2458.18 2459.54 0.002432 3.78 55.25 37.73 0.42 1.46

Munger Crossing 195 Normal Flow 180.00 2456.38 2459.24 2459.41 0.002129 3.33 56.83 38.99 0.39 1.46

Munger Crossing 195 Max Flow 200.00 2456.38 2459.44 2459.61 0.001952 3.37 65.29 47.31 0.38 1.38

Munger Crossing 232 Normal Flow 180.00 2456.16 2459.31 2459.50 0.002235 3.58 53.44 33.33 0.40 1.60

Munger Crossing 232 Max Flow 200.00 2456.16 2459.49 2459.70 0.002125 3.66 60.25 39.94 0.39 1.51

0 50 100 150 200 250

MungerRd_MiddletonCanal Plan: Proposed 7/3/2024

Main Channel Distance (ft)

E le va tio n (f t)

Legend

EG Max Flow

EG Normal Flow

WS Max Flow

WS Normal Flow

Ground

Middleton Canal Munger Crossing

0 20 40 60 80 100

MungerRd_MiddletonCanal Plan: Proposed 7/3/2024

RS = 232

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Proposed 7/3/2024

RS = 195

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Proposed 7/3/2024

RS = 164

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Proposed 7/3/2024 RS = 159.7 Culv Proposed crossing structure is a 16 ft span, 5 ft rise, 80 ft lo

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Proposed 7/3/2024

RS = 83

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Proposed 7/3/2024

RS = 45

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

MungerRd_MiddletonCanal Plan: Proposed 7/3/2024

RS = 8

Station (ft)

E le va tio n (f t)

Legend

WS Max Flow

WS Normal Flow

Ground

Attachment E

ATTACHMENT E.

RIPRAP SIZING CALCULATION

Project: ACHD No. 224008 - Munger Road Bridge #2001 (Middleton Canal)

Task: Riprap Sizing

Performed By: P. Jones, EIT

Checked By: S. Savage, PE

Date: 7/9/2024

Governing Equation

FHWA HEC No. 14 - Hydraulic Design of Energy Dissipartors for Culverts and Channels

Where:

D50 = riprap size

Q = design discharge

D = culvert rise

B = culvert span

TW = tailwater depth

= unit conversion constant (1.0)

Calculation

Variable Value Units

Q 200 ft

/s Maximum canal flow

D 4.5 ft

B 16.0 ft

TW 2.2 ft Hydraulic depth downstream of culvert from HEC-RAS model

1.0 -

D50 0.17 ft

Riprap Sizing Check

Minimum Size 1.0 Per ACHD Policy Manual, Section 3006.5

Calculated Size 0.17

Check: Minimum Size OK

Attachment F

ATTACHMENT F.

SITE PHOTOS

Photo 1: Looking at the inlet of the existing structure – Facing North

Photo 2: Looking at the outlet of the existing structure – Facing East

Photo 3: Looking upstream from crossing leading into existing structure – Facing East

Photo 4: Looking downstream from crossing exiting existing structure – Facing West