HYD__Memo.pdf

FHWA: A.Kapoor:3549:ZD: M:\PROJECTS\_FWS\LAUM\103(1)\Techserv\Hydra\Correspondence\LAUM 103(1)_AK_AOP_Memo CC: Hydraulics, Geotech, Env, HD Engineer, TS Engineer, Bridge

Form FHWA-201 U.S. DEPARTMENT OF TRANSPORTATION (Rev. 11-87) FEDERAL HIGHWAY ADMINISTRATION

MINUTE - MEMO

Use this form in lieu of transmittal slips within Dept. of Trans. when message comment is to be retained as file material. Do not prepare carbons. Not to be used in lieu of Form FHWA-121 for informal correspondence.

SUBJECT: LAUM 103(1) SICO 10(1) 104(1) 105(1) – AOP Memo

TO MESSAGE/COMMENT FROM/DATE

Nilesh Makwana Project Manager

Marc Carruthers Highway Design Manager

We have completed the hydraulic analysis for the culverts designed for Aquatic Organism Passage (AOP) for the subject project. The project involved culvert design for the Potter Farm Road, Lewis Pond Road (Site # 241), Eagle Nest Road (Site # 334-336 & Site # 331) and culvert design for AOP on Lewis Pond Road (Site # 220) and Tin Shack Road (Site 043) within Silvio O. Conte National Wildlife Refuge and Lake Umbagog National Wildlife Refuge. Our recommendations for the non AOP culverts were provided in an email on 04/17/14. For the following AOP recommendations, if the proposed bed gradation cannot be found during construction, coordination with Materials and Construction is required.

Hydrology is based on the Rational method for Site # 220 and on “Estimating the Magnitude of Peak Flows for Steep Gradient Streams in New England” (NETC) method for Site # 043. Per Chapter 7 of the PDDM, the culvert was designed to convey the 25 year peak flow under the road as well as for Aquatic Organism Passage (AOP) per FHWA HEC 26, “Aquatic Organism Passage Design Guidelines for Roadway Culverts” requirements.

Hydraulic modeling was performed using HY-8, Hydraulic Toolbox and the HEC-26 spreadsheet. For a summary of flow rates, see Table 1.

Lewis Pond Road – Site # 220 (Sta. 11+26.61):

The existing structure is a 36” corrugated metal pipe (CMP) which is perched approximately 1.5’ at the outlet indicating that the culvert could be undersized. Per the FWS personnel, the culvert serves as a barrier for AOP and needs to be replaced with a culvert designed according to the HEC – 26 guidelines.

We recommend installing a 24 foot long, 5 ft. span by 5 ft. rise reinforced box culvert (RCB) with a 1.5:1 beveled edge and headwalls. This structure should be embedded 2 feet with an upstream flowline invert of 1638.19 feet and a downstream flowline invert of 1637.18 feet. We recommend using two layers of bed gradation for the embedment. Please refer to Tables 2 and 3 for the bed gradation information and the proposed culvert summary respectively. We also recommend creating a low flow channel in the top layer with a cross slope of 1V:10H.

Abhishek Kapoor Hydraulics Engineer

THROUGH

Libby Gress Hydraulics Team Leader

7/30/2014

Tin Shack Road – Site # 043 (Sta. 31+42.51):

The existing structure is a 42” CMP which is perched approximately 3’ at the outlet indicating that the culvert could be undersized. Per the FWS personnel, the culvert serves as a barrier for AOP and needs to be replaced with a culvert designed according to the HEC – 26 guidelines.

We recommend installing a 26 foot long, 7 ft. span by 7 ft. rise RCB with a 1.5:1 beveled edge and headwalls. This structure should be embedded 3 feet with an upstream flowline invert of

1751.28 feet and a downstream flowline invert of 1750.15 feet. We recommend using two layers of bed gradation for the embedment. Please refer to Tables 2 and 3 for the bed gradation information and the proposed culvert summary respectively. We also recommend creating a low flow channel in the top layer with a cross slope of 1V:14H.

Please refer to Attachment 1 for a schematic of the proposed AOP culverts. For the proposed culvert offsets, please refer to the drainage cross section (dxs) CADD files at the following location:

M:\PROJECTS\_FWS\LAUM\103(1)\Techserv\Hydra\CADD\Drainage cross-sections

If you should have any questions or concerns with the above recommendations, please feel free to contact us.

Table 1: Design Flow Rates

Table 2: Bed Gradation Site # 220 Site # 043

Top Layer Sub Layer Top Layer Sub Layer D95 (mm) 12.7 305 47 610 D84 (mm) 7.6 225 39.4 449 D50 (mm) 1.5 161 8.9 321 D16 (mm) 0.13 16 0.9 32 D5 (mm) 0.05 2 0.3 2

Site 2 year (cfs)

10 year (cfs)

25 year (cfs)

50 year (cfs)

100 year (cfs)

Qh (cfs)

Ql (cfs)

220 21.5 32.7 39 43.8 48.5 6.7 1 043 51 109 146 175 205 21.9 1

Table 3: Culvert Summary

Station Size (ft) Length

(ft) Type

Inv. In El. (ft)

Inv. Out El. (ft)

Flowline Inv. In El.

(ft)

Flowline Inv. Out El. (ft)

Top Layer depth (ft)

Sub Layer depth (ft)

Low Flow

Channel Cross Slope

Site #220 11+26.61 5 S x 5 R 24 RCB 1636.19 1635.18 1638.19 1637.18 1 1 1V:10H Site # 043 31+42.51 7 S x 7 R 26 RCB 1748.28 1747.15 1751.28 1750.15 1 2 1V:14H

ABHISHEK

KAPOOR

Digitally signed by ABHISHEK KAPOOR DN: c=US, o=U.S. Government, ou=DOT Headquarters, ou=FHWAHQ, cn=ABHISHEK KAPOOR Date: 2014.07.30 13:17:01 -04'00'

MARY ELIZABETH

ROSE GRESS

Digitally signed by MARY ELIZABETH ROSE

GRESS

DN: c=US, o=U.S. Government, ou=DOT FHWASterlingVA, ou=FHWA FHWASterlingVA, cn=MARY ELIZABETH ROSE GRESS Date: 2014.07.30 15:20:12 -04'00'

Potter Farm 201+92.95 RCB 9 S x 5 R 1325.79 1325.67 1327.79 1327.67 2 24 Yes, 1:1 beveled edge

#331 101+98.19 CMP 5 1334.00 1333.28 1336.00 1335.28 2 29 Yes, 1:1 beveled edge 113+01.96 CMP 3 1342.65 1342.05 1343.65 1343.05 1 21 Yes, 1:1 beveled edge 113+22.88 CMP 3 1342.80 1342.54 1343.80 1343.54 1 25 Yes, 1:1 beveled edge 114+27.43 CMP 4 1342.25 1342.00 1343.25 1343.00 1 30 Yes, 1:1 beveled edge

112+94.69 CMP 4.5 1341.68 1341.44 1343.68 1343.44 2 20 Yes, 1:1 beveled edge 114+80.05 RCB 9 S x 6 R 1341.42 1341.09 1343.42 1343.09 2 22 Yes, 1:1 beveled edge

10 S x 6 R Yes, 1:1 beveled edge

LAUM 103(1), SICO 10(1) 104(1) 105(1): Summary of Hyd. Recommendations

(3 barrels)

Yes, 1:1 beveled edge

114+27.43 RCB 1340.65 1342.65 2 201340.84 1342.84

1340.76 1340.65 1342.76 1342.65 2 22

N/A Open Bottom

35 Yes, 1:1 beveled edge

#334‐336 Option 2 (3 CMPs)

#334‐336 Option 3

(1 RCB)

#334‐336 Option 4 (2 Crossings)

#241 22+70.47 Corrugated Steel Arch

#334‐336 Option 1 (Replace in Kind)

114+27.43 CMP

Flowline Inv. In El.

Flowline Inv.out El.

Embedment (ft)

Length (ft)

Headwalls

8 S x 4.17 R 1705.04 1702.99 N/A

Site Sta Type Size (ft)

Inv. In El.

(ft)

Inv.out El.

(ft)