November 2011 Structure Justification Report Kosciuszko Bridge Project Appendix E: Hydrology and Hydraulics Analysis Report

KOSCIUSZKO BRIDGE OVER NEWTOWN CREEK

HYDRAULIC DESIGN JUSTIFICATION REPORT

for

Kosciuszko Bridge over Newtown Creek

Kings & Queens County, New York

Prepared for:

New York State Department of Transportation

September 2010

Prepared by: Hardesty & Hanover, LLP

1501 Broadway New York, New York 10036

_______________________________ R. Raymond Mankbadi, PE NYPE Lic#: 073035-1 Principal Associate

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Introduction The Kosciuszko Bridge over Newtown Creek is planned to be replaced. This hydrologic and hydraulic analysis is prepared to document hydraulic conditions at the replacement bridge as they affect streambed scour, shoreline erosion protection, and other hydraulic considerations on the selection of structure type and substructure locations. In-water construction staging structures are also evaluated from a hydraulics stand point.

Existing Conditions The drainage basin contributing to the Newtown Creek is largely comprised of fully developed urban residential and industrial land use coverage. Aerial photography reveals that much of the area consists of impervious surfaces such as roads, roofs, parking lots and paved industrial areas. Minor pervious land use coverages are small urban parks and cemeteries. Within the 4900 acre drainage basin, soils information provided by the New York City Soil and Water Conservation District indicates that the soils are largely type B hydrologic soils group. Upstream of the Kosciuszko Bridge, Newtown Creek is largely a man-made, tidally influenced canal, mostly bulkheaded and aligned in straight segments, to serve as waterway transportation access for industrial business. A navigation study performed in 2005, in support of the Environmental Impact Study, documented the current and anticipated vessel demographics (USDOT/FHWA, December 2008, App. F). Proposed Conditions The Kosciuszko Bridge is to be replaced with a high-level fixed bridge over the creek with minimum vertical clearance of 90-feet over the waterway. The replacement bridge substructure will be located well behind the shoreline and will have no impact on the tidal hydraulics of the waterway. The existing piers of the Kosciuszko Bridge will be removed from the stream banks and backfilled with stone. Prior studies and document searches have indicated that plans for future dredging of the waterway exist (USACE, 2009). However, it is anticipated that the channel will not be dredged prior to this project. Temporary Construction Conditions The analysis for this project anticipated that construction platforms may be required within the waterway at the bridge site, see Appendix G, FEIS (NYSDOT, 2006). Based on the diagrams presented in Appendix G, a 108-foot channel opening was proposed between two 66-foot wide construction platforms. These platforms have been included in this study.

Analysis Design fluvial discharges are estimated using the USDA’s TR-55 Urban Hydrology for Small Watersheds, procedure and calculation software. Estimation of tidal channel discharges is accomplished according to the practice outlined in the Federal Highway Administration’s HEC-18, Evaluating Scour at Bridges. The US Army Corps of Engineer’s River Analysis Software (HEC-RAS) is used as a second calculation to compare to hand calculations and to illustrate the velocity distribution across the channel section. Tidal elevations are obtained from the National Oceanic and Atmospheric Administration (NOAA). NOAA reports tidal predictions for Newtown Creek based on The Battery tide station at the New York Harbor (Station #8518750).

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Oceanic and Atmospheric Administration (NOAA). NOAA reports tidal predictions for Newtown Creek based on The Battery tide station at the New York Harbor (Station #8518750).

Methodology USGS Topographic maps are used to define the area of the drainage basin contributing to Newtown Creek. Aerial photography and site visits are also cross referenced to verify land use coverage and flow patterns. HEC-18 Level 2 analysis procedures are applied to estimate peak stream velocities to be used in scour countermeasure design. The tidal prism peak discharge equations are applied to estimate peak tidal flows. Peak fluvial flows are added to the peak tidal estimates to result in maximum design discharges.

Assumptions − Manning’s value for the channel is 0.030. − Newtown Creek’s tidal response is assumed to be equal to that as documented at the

NOAA tidal station at New York Harbor’s The Battery. This is assumed to be a conservative application of the tidal information, as NOAA’s tidal predictions for Newtown Creek are based on a 90% high and low elevation of The Battery.

− Base fluvial flow is negligible. − No documented 500-year storm rainfall amount was found. Therefore, peak

discharge of the 500-year event is conservatively estimated to be 1.7 of the 100-year event.

− Peak tidal flow occurs at the midpoint between high and low tide.

Scenarios for Design Flood Flow − Normal tide is checked to validate methodology compared to observed conditions. − 100-year tidal peak ebb flow plus the 100-year fluvial runoff peak flow. − 500-year tidal peak ebb flow plus the 500-year fluvial runoff peak flow. − Temporary Construction Conditions, Normal Tide and 100-year tidal peak ebb flow

plus the 100-year fluvial runoff peak flow. Results

Design Discharges, Elevations and Velocities – Existing Conditions (NGVG1929) 100-Yr

Storm Tide 500-Yr

Storm Tide Maximum storm tide elevation, FT 9.60 11.9 Mean storm tide elevation, FT 3.70 4.85 Mean Lower Low Water elevation, FT -2.21 -2.21 Tidal prism volume, CFE6 38.9 46.6 Net Waterway Area at mean tide elevation (Ac), SF 4,500 4,788 Tidal Period, time between peaks, seconds 45,000 45,000 Tidal peak discharge, CFS 2,720 3,250 Fluvial peak runoff discharge, CFS 6,830 11,610 Maximum Discharge (Qmax), CFS 9,550 14,860 Peak Mean Velocity (Vmax), FT/S 2.1 3.1 Average Flow Depth (Ac/W), FT 18.0 19.2

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HEC-RAS Analysis The following cross sections from HEC-RAS depict the velocity distribution across the channel at the bridge site. Cross Sections are based on depth soundings collected in April 2009 (Malinowski, 2010). An exhibit is provided (see page 5) which depicts existing conditions for the 100-yr and 500-yr flows. An exhibit is provided (see page 6) which shows the Proposed Conditions for the 100-yr and 500-yr flows. An exhibit is provided (see page 7) which illustrates the proposed dredged conditions with construction platforms in place at the bridge site during construction for the normal tide and the 100-year flow. Since the peak discharge occurs well within the normal banks of Newtown Creek, the bridge replacement causes no appreciable effect on the average stream velocity. If the channel is not dredged and the platforms are not constructed at the bridge site, the findings of the analysis are still valid. Rip Rap Sizing Calculations It is desired to remove the existing piers from the creek banks and backfill with granular material and stone. Also, the shoreline is to be regraded and shoreline protection restored or constructed where none exists. Two considerations were checked to determine what the controlling parameters are for stone fill and rip-rap sizing: 1) abutment scour conditions, and 2) wave action on the shoreline. Wave action is assumed to be solely from vessels due to the narrowness of the canal as well as the urban and inland nature of the site. Calculations for stone sizing were performed according to HEC-23 guidance for abutment scour countermeasures and HEC-25 guidance for shoreline armoring. The scouring conditions caused by vessel wave action appear to be the more severe condition and controls sizing of materials. Where it is desired to use stone fill to backfill exposed shoreline areas, medium grade stone fill conforming to NYSDOT Standard Specifications may be used. The NYSDOT Standard Specification for Dry Rip-Rap is of more than adequate size to serve as shoreline protection, as the specifications require all Dry Rip-Rap stones to exceed 100 pounds. For Stone Fill at the surface and exposed to wave action, the median stone weight (W50) should be on the order of 75 lbs, be placed at a side slope not to exceed 1.5H:1V. Steeper slopes are possible, but require larger, heavier stones. The stone should be placed with a minimum thickness of twice the median stone diameter, on an underlayment of stone bedding material and geotextile fabric per standard NYSDOT details and specifications.

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Detailed sizing calculations are provided in Appendix E. Typical sections of the shoreline protection for the two study conditions (undredged and dredged) are illustrated below.

UNDREDGED TYPICAL SECTION

DREDGED TYPICAL SECTION

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Existing Bridge, 100-Year Ebb Flow + 100-Year Fluvial Flow

0 100 200 300 400 500-40

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Newtown Creek Plan: Existing 3/11/2010 RS = 1100 BR Kosciuszko Bridge

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Existing Bridge, 500-Year Ebb Flow + 500-Year Fluvial Flow

0 100 200 300 400 500-40

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Newtown Creek Plan: Existing 3/11/2010 RS = 1100 BR Kosciuszko Bridge

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Proposed Bridge, 100-Year Ebb Flow + 100-Year Fluvial Flow

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Newtown Creek Plan: Proposed 3/11/2010 RS = 1100 BR Kosciuszko Bridge

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Proposed Bridge, 500-Year Ebb Flow + 500-Year Fluvial Flow

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Newtown Creek Plan: Proposed 3/11/2010 RS = 1100 BR Kosciuszko Bridge

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Construction Conditions, Normal Tide Conditions

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Newtown Creek Plan: Construction 3/11/2010 RS = 1100 BR Kosciuszko Bridge

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Construction Conditions, 100-Year Ebb Flow + 100-Year Fluvial Flow

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Newtown Creek Plan: Construction 3/11/2010 RS = 1100 BR Kosciuszko Bridge

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Bibliography and References 1. Federal Emergency Management Agency. (September 5, 2007). Flood Insurance Study City of

New York, New York Bronx County, Richmond County, New York County, Queens County, Kings County (FIS Number 360497V000A). Washington DC: Government Printing Office.

2. Malinowski, J.G., PLS (March 8, 2010). Hydraulic Section Report, Contract No. D015624, PIN

X729.77, Rehabilitation/Replacement of the Kosciuszko Bridge over Newtown Creek, Kings & Queens Counties, NY. New York: MJ Engineering and Land Surveying, P.C.

3. New York City Soil Survey Staff. (2005) New York City Reconnaissance Soil Survey. United

States Department of Agriculture, Natural Resources Conservation Service, Staten Island, NY. 4. New York State Department of Transportation (July 2006), Final Environmental Impact Statement,

Newtown Creek Channel Condition and Material Transport Report, Appendix G. 5. Ocean Surveys, Inc., (April 2009) Newtown Creek, New York Conditions Survey, Department of the

Army, New York District Corps of Engineers, New York, NY. 6. Sorenson, Robert M. (Dec 1997). Prediction of Vessel-Generated Waves with Reference to Vessels

Common to the Upper Mississippi River System. Bethlehem, PA, Lehigh University. 7. U.S. Army Corps of Engineers, Huntington District. (1980). Gallipolis Locks and Dam

Replacement, Ohio River, Ph I, Advanced Engineering and Design Study, App. J, Vol. 1, Environmental & Social Impact Analysis.

8. U.S. Army Corps of Engineers, New York District. (July 15, 2009). Report of Channel

Conditions, ER-1130-2-306. Newtown Creek, N.Y. 9. U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Center for

Operational Oceanographic Products and Services (CO-OPS), Tides & Currents retrieved December 29 and 31, 2009 from http://tidesandcurrents.noaa.gov/

10. U.S. Department of the Interior. (1967). Roughness Characteristics of Natural Channels, H. H.

Barnes, Jr., r, 1967. Washington DC: Government Printing Office. 11. U.S. Department of Transportation Federal Highway Administration. (December 2000). Guide for

Selecting Manning’s Roughness Coefficients for Natural Channels and Flood Plains (Reprint of U.S. Geological Supply Paper WSP2339). (Publication No. FHWA-TS-84-207). Washington DC: Government Printing Office.

12. U.S. Department of Transportation Federal Highway Administration. (May 2001). HEC-18

Evaluating Scour at Bridges, 4th Ed. (Publication No. FHWA-NHI-01-001). Springfield VA: Technical Information Service.

13. U.S. Department of Transportation Federal Highway Administration. (Mar 2001). HEC-23 Bridge

Scour and Stream Instability Countermeasures, 2nd Ed. (Publication No. FHWA-NHI-01-003). Springfield VA: Technical Information Service.

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14. U.S. Department of Transportation Federal Highway Administration. (December 2004). HEC-25 Tidal Hydrology, Hydraulics, and Scour at Bridges, 1st Ed. (Publication No. FHWA-NHI-05-077). Springfield VA: Technical Information Service.

15. U.S. Department of Transportation Federal Highway Administration. (June 2008). HEC-25

Highways in the Coastal Environment, 2nd Ed. (Publication No. FHWA-NHI-07-096). Springfield VA: Technical Information Service.

16. U.S. Department of Transportation Federal Highway Administration. (December 2008) Final

Environmental Impact Statement Final Section 4(f) Evaluation, FHWA-NY-EIS-07-01-F. This report prepared by Joseph Lee Adams, III, PE, CME, Project Engineer. Mr. Adams is a licensed Professional Engineer and Certified Municipal Engineer in the state of New Jersey, with 15 years experience in transportation and civil works related civil engineering for both public and private owners of roads, bridges, and dams. He has extensive experience in storm water management design, analysis, and environmental permitting, tidal and fluvial riverine modeling, extreme flood event modeling and dam breach analysis.

Appendix

A. Exhibits

E1 Drainage Area Map E2 Channel Section E3 HEC-RAS Exhibit E4 Tidal Prism Exhibit

B. TR-55 Report C. HEC-25 Calculations D. NOAA Tidal Datum Information E. Rip-Rap Stone Fill Calculations

WinTR-55 Current Data Description

--- Identification Data ---

User: JLA Date: 1/15/2010Project: 2461 Units: EnglishSubTitle: Newtown Creek Areal Units: AcresState: New YorkCounty: KingsFilename: C:\2461\TR55\2461-TR55.w55

--- Sub-Area Data ---

Name Description Reach Area(ac) RCN Tc ------------------------------------------------------------------------------A1 G-H 3567 84 2.611 A2 G-H 868.4 87 1.31 A3 H-I 467.9 88 1.11

Total area: 4903.30 (ac)

--- Storm Data --

Rainfall Depth by Rainfall Return Period

2-Yr 5-Yr 10-Yr 25-Yr 50-Yr 100-Yr 1-Yr (in) (in) (in) (in) (in) (in) (in)-------------------------------------------------------------------------------- 3.5 4.5 5.0 6.0 7.0 7.5 2.7

Storm Data Source: Kings County, NY (NRCS)Rainfall Distribution Type: Type IIIDimensionless Unit Hydrograph: <standard>

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Storm Data

Rainfall Depth by Rainfall Return Period

2-Yr 5-Yr 10-Yr 25-Yr 50-Yr 100-Yr 1-Yr (in) (in) (in) (in) (in) (in) (in)-------------------------------------------------------------------------------- 3.5 4.5 5.0 6.0 7.0 7.5 2.7

Storm Data Source: Kings County, NY (NRCS)Rainfall Distribution Type: Type IIIDimensionless Unit Hydrograph: <standard>

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JLA 2461 Newtown Creek Kings County, New York

Watershed Peak Table

Sub-Area Peak Flow by Rainfall Return Period or Reach 2-Yr 100-YrIdentifier (cfs) (cfs)----------------------------------------------------------------------------------SUBAREASA1 1746.12 5041.06

A2 766.47 2039.19

A3 474.59 1231.98

REACHESG-H 2170.08 6211.61 Down 2162.92 6183.48

H-I 2400.71 6845.11 Down 2395.42 6829.12

OUTLET 2395.42 6829.12

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Hydrograph Peak/Peak Time Table

Sub-Area Peak Flow and Peak Time (hr) by Rainfall Return Period or Reach 2-Yr 100-YrIdentifier (cfs) (cfs) (hr) (hr) ----------------------------------------------------------------------------------SUBAREASA1 1746.12 5041.06 13.73 13.65

A2 766.47 2039.19 12.87 12.85

A3 474.59 1231.98 12.73 12.73

REACHESG-H 2170.08 6211.61 13.37 13.35 Down 2162.92 6183.48 13.53 13.43

H-I 2400.71 6845.11 13.36 13.29 Down 2395.42 6829.12 13.43 13.29

OUTLET 2395.42 6829.12

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Sub-Area Summary Table

Sub-Area Drainage Time of Curve Receiving Sub-AreaIdentifier Area Concentration Number Reach Description (ac) (hr)--------------------------------------------------------------------------------A1 3567.00 2.611 84 G-H A2 868.40 1.310 87 G-H A3 467.90 1.110 88 H-I

Total Area: 4903.30 (ac)

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Reach Summary Table

Receiving Reach Routing Reach Reach Length MethodIdentifier Identifier (ft)----------------------------------------------------------------------

G-H H-I 2590 CHANNEL H-I Outlet 1270 CHANNEL

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Sub-Area Time of Concentration Details

Sub-Area Flow Mannings's End Wetted TravelIdentifier/ Length Slope n Area Perimeter Velocity Time (ft) (ft/ft) (sq ft) (ft) (ft/sec) (hr)--------------------------------------------------------------------------------A1 SHEET 50 0.0050 0.150 0.156 SHALLOW 16060 0.0100 0.025 2.195 CHANNEL 5240 5.600 0.260

Time of Concentration 2.611 ========

A2 SHEET 50 0.0020 0.150 0.225 SHALLOW 9290 0.0160 0.025 1.004 CHANNEL 1460 5.000 0.081

Time of Concentration 1.31 ========

A3 SHEET 50 0.0200 0.150 0.090 SHALLOW 8225 0.0200 0.025 0.795 CHANNEL 1700 2.100 0.225

Time of Concentration 1.11 ========

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Sub-Area Land Use and Curve Number Details

Sub-Area Hydrologic Sub-Area CurveIdentifier Land Use Soil Area Number Group (ac)--------------------------------------------------------------------------------A1 Open space; grass cover 50% to 75% (fair) B 422 69 Commercial & business B 293 92 Residential districts (1/8 acre) B 2852 85

Total Area / Weighted Curve Number 3567 84 ==== ==

A2 Commercial & business B 289.5 92 Residential districts (1/8 acre) B 578.9 85

Total Area / Weighted Curve Number 868.4 87 ===== ==

A3 Commercial & business B 221 92 Residential districts (1/8 acre) B 246.9 85

Total Area / Weighted Curve Number 467.9 88 ===== ==

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Reach Channel Rating Details

Reach Reach Reach Friction Bottom Side Identifier Length Manning's Slope Width Slope (ft) n (ft/ft) (ft)--------------------------------------------------------------------------------

G-H 2590 0.03 0.001 170 .1 :1 H-I 1270 0.03 0.001 255 .1 :1

Reach End Top Friction Identifier Stage Flow Area Width Slope (ft) (cfs) (sq ft) (ft) (ft/ft)-------------------------------------------------------------------------------- G-H 0.0 0.000 0 170 0.001 0.5 83.586 85 170.1 1.0 264.465 170.1 170.2 2.0 833.964 340.4 170.4 5.0 3765.243 852.5 171 10.0 11585.196 1710 172 20.0 34732.857 3440 174

H-I 0.0 0.000 0 255 0.001 0.5 125.523 127.5 255.1 1.0 397.602 255.1 255.2 2.0 1256.589 510.4 255.4 5.0 5709.709 1277.5 256 10.0 17740.698 2560 257 20.0 54086.931 5140 259

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1) HEC 23 Rip-Rap Sizing for Abutment Scour

Stream Velocity V 3.1 ft/s (From Hydrology & Hydraulics Analysis)Accel. Constant g 32.2 ft/s2

Avg Chan. Depth. y 19.2 ft (From Hydrology & Hydraulics Analysis)K K 1Specific Gravity SG 2.65 (Typical granite quarry stone)Froude Number (Fr) = V/(gy).5 0.12 < 0.8

Mean Stone Diameter D50 = yK/(SG-1) [V2/(gy)] 0.18 ft 2.17 in (HEC 23, Equation 8.2)

2) HEC 25 Rip-Rap Sizing for Shoreline Armoring

Wave Height Hm 1.9 ft (see estimation below)Side Slope S 1.5 H:VMedian Weight of Stone (W50) = 16.7Hm

3/S 74.3 lbs (HEC 25, Equation 6.2)

Wmin = 0.125W50 W50 Wmax=4W50

Gradation (lbs): 9.3 74.3 297Thickness twice the median stone diameter, plus the filter layer

Vessel Generated Wave Height Estimation (Huntington District, USACOE)Channel CharacteristicsArea (Ac) 4500 sf Width 250 ft Avg Depth 18 ft

Vessel Characteristics Barge Tanker Tug Sm Craft Lg Craft (From Navigation Rpt)

Length Lv 150 300 100 35 60 ftWidth Wv 45 60 50 12 18 ftDraft D 14 15 14 4 4 ftChannel Section CoefficientAc/(DxWv) Sc 7.1 5.0 6.4 93.8 62.5Velocity V 5 5 7 11 10 mphHm = 0.0448V2(D/Lv)

.5(Sc/(Sc-1))2.5(USACOE Equation)

Wave Height Hm 0.5 0.4 1.3 1.9 1.2 ft

Results SummaryStone sizing for wave action shoreline protection controls over riverine scour protection.

Use a gradation of stone conforming to the above HEC 25 recommendation, and generally conformingto NYSDOT Spec 620, Stone Filling, Medium and Bedding Material. Geotextile underlayment shallconform to Spec 737-01 Geotextiles. Place Stone Filling at slopes not to exceed 1.5:1 (H:V)

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