January 12, 2017

Ms. Georgia Gray, Chairperson Village of Voorheesville Planning Commission 29 Voorheesville Avenue Voorheesville, NY 12186

RE: Stewart’s Shops – 112 Maple Avenue Floodplain Evaluation CHA Project No.: 31753

Dear Ms. Gray:

CHA Consulting Inc. (CHA) performed a Floodplain Evaluation in response to the following comment raised in a letter dated December 22, 2016 from Lauren Sherman of C.T. Male Associates: “The Applicant shall provide a quantitative analysis of any potential impacts the proposed fill in the floodplain (outside of the floodway) could have on adjacent properties.” This letter summarizes the scope and methodology utilized in CHA’s evaluation along with our findings and recommendations.

Background

The proposed project includes the construction of a new Stewart’s in the Village of Voorheesville (Village), Albany County, (See Figure 1 – Location Map). The proposed site is located along Vly Creek just southeast of the intersection of Route 85A (Maple Ave) and Altamont Road. A review of the effective Federal Emergency Management Agency (FEMA) Flood Insurance Study (FIS) for Albany County (March 2015), indicates that Vly Creek has been studied by detailed methods (Zone AE), and as such a base (100-year) flood elevation (floodplain) and floodway have been established through the project site (See Figure 2 – FEMA Map). Although the most recent hydrologic and hydraulic analysis for Vly Creek was completed in 1980, the floodplain was remapped on updated topography during the most recent countywide revision.

For the purposes of the National Flood Insurance Program (NFIP), the concept of a floodway is used to assist in the matter of flood management. Under this concept, the 100-year floodplain is divided into a floodway and a floodway fringe (floodplain). The floodway is the area of the channel, which must be kept free of encroachment so the 100-year flood can be conveyed while limiting the increase to flood elevations. As a minimum standard, FEMA limits this increase to one foot. The requirements pertaining to floodplain management contained in the FEMA Flood Damage Prevention Guidelines require that the following conditions be met:

 Any structures and/or fill associated with the proposed work cannot raise upstream 100-year flood elevations more than a foot at any point.

 All encroachments including fill, new construction, substantial improvements, and other development are prohibited within the limits of the floodway unless a technical evaluation demonstrates that such encroachments shall not result in any increase in floodway water surface elevations during the occurrence of the base flood.

Ms. Georgia Gray, Chairperson January 12, 2017 January 9, 2017 Village of Voorheesville Planning Commission Page 2 Page 2

The proposed project includes the placement of 4,000 cubic yards (cy) of fill within the 100-year floodplain. Since no fill is being placed within the floodway, a detailed floodplain analysis is not typically warranted; however, CHA conducted an evaluation in response to a comment made by C.T. Male Associates regarding potential flooding impacts to adjacent landowners.

A detailed explanation of the floodplain evaluation is provided below. All elevations provided below are based on unobstructed flow and are referenced to the North American Vertical Datum of 1988 (NAVD88).

Hydrology

The peak discharges for Vly Creek were developed for the FIS using the United States Army Corps of Engineers (ACOE) Regional Frequency Study. Based on the FIS, the 100-year peak discharge at the Route 85A Bridge, located immediately upstream of proposed site was 2,330 cubic feet per second (cfs). Since this flow was used in the development of the effective FIS, CHA utilized this value for the floodplain evaluation described below. Supporting files from the FIS can be found in the Technical Appendix.

Hydraulic Model

Since FEMA studied Vly Creek by detailed methods, CHA contacted the New York State Department of Environmental Conservation (NYSDEC) and requested a copy of the FIS backup data. Although the 1980 backup data could not be obtained, CHA believes that the original model is likely outdated. According to bridge inspection reports, both the Route 85A and Stonington Hill Road Bridges were replaced in 1998 and 1999, respectively. Additionally, detailed topographic data (LiDAR) was released for Albany County in 2008.

Therefore, CHA developed a hydraulic model using the ACOE Hydrologic Engineering Center River Analysis System (HEC-RAS) software (Version 5.0.3). The modeled reach begins approximately 500 feet upstream of the Route 85A Bridge and extends downstream approximately 1,200 feet, ending near the Saint Matthew’s Church (FIS Section H). The cross section geometry for the model was developed from the 2008 Albany County LiDAR dataset using the HEC-GeoRAS extension for ArcMap (See Figure 3 – Cross Section Map). The LiDAR was supplemented with survey data of the channel and bridge, which was collected by GYMO Architecture, Engineering and Land Surveying, P.C. in December of 2016. Using the HEC-GeoRAS extension, CHA modeled all structures within the floodplain using blocked obstructions. In order to account for the potential losses associated with the Route 85A Bridge, the contraction and expansion coefficients for cross sections around the bridge were updated to 0.3 and 0.5, respectively. Finally, a known water surface elevation from FIS Section H (Floodway Data Table) was utilized as the downstream boundary condition.

Using the existing condition model, CHA compared the 100-year water surface elevations from the model with those published in the FIS. In general, the water surface elevations from the model were found to be similar (within 0.5 feet) to those published in the FIS. Since the original study was completed in 1980, CHA believes that the minor differences in the water surface elevation are likely the result of updated station elevation data and localized changes to the channel and overbanks (development) over the past 36 years.

CHA then developed the proposed condition model by revising the existing condition to reflect the proposed grading shown in the 2016 Design Plans. Changes were limited to cross-sections 614 and 732 and represent the fill

Ms. Georgia Gray, Chairperson January 12, 2017 January 9, 2017 Village of Voorheesville Planning Commission Page 3 Page 3 associated with the installation of a retaining wall and the expansion of on-site parking. Detailed modeling output and a comparison of the existing and proposed cross sections can be found in the Technical Appendix.

Model Results

Based on review of recent aerial imagery and the LiDAR dataset, 2 residential structures were identified and used in to evaluate potential incremental flooding impacts. The structures are located on the opposite bank, immediately upstream of the project site and are shown as blocked obstructions in model cross-sections 833 and 896. Based on the results of the existing and proposed HEC-RAS model (floodplain), both of these structures are located above the 100-year (floodplain) water surface elevation. Additionally, the maximum increase in water surface elevation associated with the addition the proposed fill is less than 0.1 ft, which is attenuated to 0.0 ft at the upstream limits of the model. As such, CHA does not anticipate any incremental impacts due to the proposed project. A summary of the water surface elevations and modeled finished floor elevations is provided in Table 1 on the following page. Supporting documentation and model output can be found in the Technical Appendix.

Table 1 - 100-year Floodplain Results

Water Surface Elevation Modeled Finished Floor 100-year Floodplain Existing (ft) Proposed (ft) Elevation (ft) XS 1292 (School) 332.2 332.2 328.8 XS 896 (House) 330.7 330.7 331.9 XS 833 (House) 330.7 330.8 331.9 XS 732 (House) 330.7 330.6 331.7 XS 614 330.5 330.5 N/A

Although the proposed fill is to remain outside of the regulated floodway, CHA utilized the existing and proposed model, explained above, to develop a floodway analysis. Since the original backup data was not available, CHA determined the effective floodway limits in ArcMap using the National Flood Hazard Layer (NFHL) and maintained them in both models. Based on a comparison of the existing and proposed condition, the fill associated with the proposed project does not increase the floodway elevations through the modeled reach. Table 2 provides a hydraulic summary for the 100-year floodway evaluation. Detailed results can be found in the Technical Appendix.

Table 2 - 100-year Floodway Results

Water Surface Elevation Modeled Finished Floor 100-year Floodway Existing (ft) Proposed (ft) Elevation (ft) XS 1292 (School) 333.0 333.0 328.8 XS 896 (House) 331.4 331.4 331.9 XS 833 (House) 331.4 331.4 331.9 XS 732 (House) 331.3 331.3 331.7 XS 614 331.2 331.2 N/A

Ms. Georgia Gray, Chairperson January 12, 2017 January 9, 2017 Village of Voorheesville Planning Commission Page 4 Page 4

Conclusion

As explained above, the proposed project includes the addition of approximately 4,000 cubic yards of fill within the 100-year floodplain of Vly Creek. Although the fill is located outside of the regulated floodway, a floodplain evaluation was conducted to determine if there are incremental impacts to adjacent properties. Based on the results of the analysis, the maximum increase in water surface elevation associated with the addition the proposed fill is 0.1 ft, which is attenuated to 0.0 ft at the upstream limits of the model. As such, the proposed project is not expected to result in incremental impacts to adjacent properties and is therefore consistent with FEMA Flood Damage Prevention Guidelines.

If you have any questions regarding the results of the analysis please do not hesitate to contact me at (518) 453- 4540.

Sincerely,

Kris Detlefsen, P.E. Section Manager - Hydraulics & Hydrology

cc: Lauren Sherman, CT Male Chuck Marshall, Stewart’s Shops Tony Stellato, CHA

Enclosure KKD/ogm

V:\Projects\ANY\K4\31753\Reports\H&H\Floodplain Evaluation - Stewarts Shops .doc

TECHNICAL APPENDIX

Stewart’s Shops Floodplain Evaluation Voorheesville, Albany County, New York

01 - Figures

Stewart’s Shops Floodplain Evaluation Voorheesville, Albany County, New York

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Project Location

Copyright:© 2013 National Geographic Society, i-cubed, Sources: Esri, DeLorme, USGS, NPS

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ Town of Voorheesville, Albany County, New York ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ I ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ Issue Date: 1/9/2017 Project No. : 31753 ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ 1 inch = 2,000 feet Document Path: V:\Projects\ANY\K4\31753\Data\GIS\Figure 2.mxd Last Saved: 1/9/2017 12:17:51 PM User: 3950

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￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ Town of Voorheesville, Albany County, New York ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ I ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ Issue Date: 1/9/2017 Project No. : 31753 ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ 1 inch = 200 feet Document Path: \\cha-llp.com\proj\Projects\ANY\K4\31753\Data\GIS\Figure 3.mxd Last Saved: 1/9/2017 12:28:53 PM User: 3950

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Project Location (Proposed Grading)

7 7 7 . 9 6 1 . 9 8 3 2 6 3 . . 8 2 5

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￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ Town of Voorheesville, Albany County, New York ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ I ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ Issue Date: 1/9/2017 Project No. : 31753 ￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ 1 inch = 200 feet

02 - Hydrology

Stewart’s Shops Floodplain Evaluation Voorheesville, Albany County, New York

VOLUME 1 OF 2

ALBANY COUNTY, NEW YORK (ALL JURISDICTIONS)

COMMUNITY COMMUNITY NAME NUMBER ALBANY, CITY OF 360001 ALTAMONT, VILLAGE OF 360002 BERNE, TOWN OF 360003 BETHLEHEM, TOWN OF 361540 COEYMANS, TOWN OF 360005 COHOES, CITY OF 360006 COLONIE, TOWN OF 360007 COLONIE, VILLAGE OF* 365377 GREEN ISLAND, VILLAGE OF 360009 GUILDERLAND, TOWN OF 360010 KNOX, TOWNSHIP OF 360011 MENANDS, VILLAGE OF 360012 NEW SCOTLAND, TOWN OF 360013 RAVENA, VILLAGE OF 361346 RENSSELAERVILLE, TOWN OF 360014 VOORHEESVILLE, VILLAGE OF 360015 WATERVLIET, CITY OF 360016 WESTERLO, TOWN OF 360017

*NO SPECIAL FLOOD HAZARD AREAS IDENTIFIED

EFFECTIVE: MARCH 16, 2015

Federal Emergency Management Agency

FLOOD INSURANCE STUDY NUMBER 36001CV001A

Menands, Village of: The hydrologic and hydraulic analyses for the September 1979 study were prepared by the U.S. Geological Survey for the Federal Insurance Administration, under Inter-Agency Agreement No. IAA-H-9-77, Project Order No. 11 and Amendment No. 2. This work, which was completed in April 1978, covered all significant flooding sources affecting the Village of Menands. New Scotland, Town of: The hydrologic and hydraulic analyses for the June 1982 study were prepared by LMS/Jackson Associates for the FEMA, under Contract No. H-4736. This work was completed in April 1980. Voorheesville, Village of: The hydrologic and hydraulic analyses for the June 1982 study were prepared by LMS/Jackson Associates for the FEMA under Contract No. H-4736. This work was completed in April 1980. Watervliet, City of: The hydrologic and hydraulic analyses for the July 1979 study were prepared by the U.S. Geological Survey for the Federal Insurance Administration, under Inter-Agency Agreement No. IAA-H-9-77, Project Order No. 11 and Amendment No. 2. This work, which was completed in April 1978, covered all significant flooding sources affecting the City of Watervliet. Westerlo, Town of: The hydrologic and hydraulic analyses for the August 1989 study were prepared by McCoy-Jackson Associates for the FEMA, under Contract No. EMW-84-C-1603. This work was completed in June 1987.

There are no previous FISs or FIRMs for the Village of Colonie and no previous FISs for the Towns of Berne and Rensselaerville; the Township of Knox and the Village of Ravena; therefore, the previous authority and acknowledgement information for these communities is not included in this FIS. These communities may not appear in the Community Map History table (Section 6.0). The NYSDEC and FEMA entered into a Cooperative Technical Partners (CTP) Agreement to collaboratively produce this countywide FIS. Revised hydrologic and hydraulic analyses for all approximate studies and for detailed studies on the , Tributary 10 to Normans Kill, Tributary 1 to Tributary 10 to Normans Kill, Patroon Creek, Dry River, , Hannacrois Creek, Tributary 1 to Hannacrois Creek, Krum Kill, and Tributary 4 to Bozen Kill were prepared by Gomez and Sullivan Engineers, P.C. and PAR Government Services for the NYSDEC. This work was completed in December 2011. The digital base map information shown on the FIRMs was provided by the NYSDEC. This information was derived from the New York State Office of Cyber Security & Critical Infrastructure Coordination from aerial photography published in November 2007. The projection used for the preparation of the digital FIRMs was Universal Transverse Mercator (UTM), Zone 18. The horizontal datum was NAD 83, GRS1980 spheroid. Differences in datum, spheroid, projection or UTM zones used in the production of

3 Vly Creek

The hydrologic analysis of Vly Creek required two methods of computation to derive the peak discharges. In the Village of Voorheesville, and in the Town of New Scotland downstream of the confluence with Tributary C, the USACE Regional Frequency Study was used. This statistical method developed peak discharges for selected recurrence intervals based upon the parameters such as basin size, mean annual flood peak, standard deviation and skew coefficient (USACE, 1974b)(FEMA, 1982b; 1982c).

In the Town of New Scotland upstream of the confluence with Station 23.000 Tributary, where the discharge area is too small to use the USACE Regional Frequency Study, the rational method was used, and utilized the parameters of basin size, time of concentration and rainfall intensity (FEMA, 1982b).

Revised Countywide Analyses

Detailed and Limited Detailed Studies

The majority of streamflow within Albany County is unregulated. Hydrologic analyses were completed to establish peak discharge-frequency relationships for each flooding source studied by detailed and limited detailed study methods. For these studies, discharges were nominated at the same nomination locations provided in the effective Flood Insurance Studies (FIS) for the Albany County communities, at tributary confluences, and other locations where appropriate.

Methods for nominating discharges for the detailed and limited detailed study streams included gage analysis, use of the USGS 2006 New York State regional regression equations, NRCS TR-55 runoff analysis, the rational method, or a combination of these methods. Newly-calculated discharges were compared to the effective FIS discharges where they exist. The decision to revise a discharge value or reuse the effective value was based on standard practices described in Appendix C of FEMA Guidelines and Specifications for Flood Hazard Mapping Partners (Section C.1.2.1 under the heading “Determining Statistical Significance”). In addition, per FEMA guidelines (Section C.1.2.2), proposed discharge values for detailed stream segments will be compatible with those in the effective analyses at the limits of detailed study

For the detailed study streams having a gage record of sufficient length (minimum 10 years of record [USGS, 1982]), a discharge-frequency gage analysis methodology was used to nominate discharges. This methodology utilized a log-Pearson Type III analysis (LP III) for the available records in accordance with USGS Bulletin 17B (USGS, 1982). In rural and unregulated flow situations, the gage analysis was weighted with the 2006 New York State regional regression equations in accordance with the USGS Scientific Investigations Report (SIR) 2006-5112 “Magnitude and Frequency of Floods in New York” (Lumia, 2006). For the regulated, rural streams, only the regulated years of record were used to nominate discharges using a log-Pearson Type III manual probability plot. The regression equations were not used for regulated streams.

For ungaged streams, discharges were nominated using the regional regression equation method in accordance with the USGS Scientific Investigations Report 2006-5112 “Magnitude and Frequency of Floods in New York” (Lumia, 2006). This method related

20 TABLE 5 - SUMMARY OF DISCHARGES - DETAILED STUDIES (continued) PEAK DISCHARGES (cfs) DRAINAGE AREA 10-percent 2-percent 1-percent 0.2-percent FLOODING SOURCE AND LOCATION (square Annual Annual Annual Annual miles) Chance Chance Chance Chance PATROON CREEK At confluence with 14.26 1,838 2,797 3,350 4,686 SALT KILL At State Highway 787 2.61 190 240 270 300 SAND CREEK At City of Albany-Town of Colonie boundary 2.68 510 800 930 1,300 SHAKER CREEK At confluence with 12.2 820 1,600 2,000 3,500 STATE BASIN At Salt Kill 3.30 190 240 270 300 At Mohawk River Overflow (Fifth Branch Mohawk River) (1) 0 740 6,400 19,000 19,500 feet upstream of mouth 24.2 1,688 3,264 4,283 7,420 Upstream of Dowers Kill 18.8 1,378 2,700 3,561 6,236 VLY CREEK At confluence with Normans Kill 16.5 1,203 2,245 2,903 4,948 Upstream of confluence with Tributary A 13.5 1,024 1,929 2,505 4,307 At State Route 85A 12.3 950 1,798 2,339 4,037 Upstream of confluence with Tributary B 9.5 772 1,480 1,935 3,374 Upstream of confluence with Tributary C 2.42 559 698 838 1,164 At Tygert Road Bridge 1.39 481 615 695 909 (1) A drainage area value is not appropriate at this location because each branch of the Mohawk River downstream of the New York State Dam carries only a portion of the total Mohawk River discharge (FEMA, 1979e).

32 State Basin

In the Village of Green Island, preliminary profiles for the State Basin were developed for two sources of flooding, one of which being Hudson River backwater and overflow from the Fifth Branch Mohawk River. Starting elevations were determined from the Hudson River profiles.

Vlomen Kill

The detailed study for the Vloman Kill was performed for the Town of Colonie Flood Insurance Study (1979). Starting water-surface elevations for the Vloman Kill were taken at critical depth several hundred feet downstream of the beginning of the detailed study.

Vly Creek

Detailed studies for Vly Creek were performed for the Town of Guilderland Flood Insurance Study (1982), the Town of New Scotland Flood Insurance Study (1982) and the Village of Voorheesville Flood Insurance Study (1982). In the Towns of Guilderland and New Scotland, starting water-surface elevations for Vly Creek were started at the confluence with Normans Kill using the slope/area method. In the Town of Voorheesville, starting water surface elevations for Vly Creek were taken from the Flood Insurance Study for the Town of New Scotland (FEMA, 1982b). Revised Countywide Analyses Analyses of the hydraulic characteristics of flooding from the stream sources studied were carried out to provide estimates of the elevations of floods of the selected recurrence intervals. Users should be aware that flood elevations shown on the Flood Insurance Rate Map (FIRM) represent rounded whole-foot elevations and may not exactly reflect the elevations shown on the Flood Profiles or in the Floodway Data Table in this FIS report. Flood elevations shown on the FIRM are primarily intended for flood insurance rating purposes. For construction and/or floodplain management purposes, users are cautioned to use the flood elevation data presented in this FIS report in conjunction with the data shown on the FIRM. In this countywide analysis, water surface elevations for floods of the selected recurrence intervals for detailed, limited detail, and approximate studies were computed using the USACE Hydrologic Engineering Center River Analysis System (HEC-RAS) river modeling software program (Version 4.0). The HEC-RAS model for each flooding source is based on cross section geometry generated using manual and semi-automated methods derived from GIS techniques and data. Cross section elevations were extracted from a Digital Terrain Model (DTM). The DTM was generated by combining overbank elevation data from an aerial Light Detection and Ranging (LiDAR) survey with data from a traditional field survey of the stream channel and the immediate overbank areas. For detailed studies, cross sections were field surveyed at close intervals just upstream and downstream of bridges, culverts, dams, and other hydraulic obstructions, at natural control sections along the stream length, and at significant changes in ground relief, land use, or land cover. Detailed structural geometry for bridges and culverts was also obtained from NYSDOT as-built drawings where they were available. A stream centerline was located using geographically rectified aerial photography and the DTM. The centerline served as a base line to define hydraulic model distances along the

44 stream channel as indicated on the Flood Profile and the Floodway Data Table. Selected cross sections used in the detailed hydraulic analysis are located on the Flood Profiles (Exhibit 1) and on the FIRM and are relative to distances along this base line. Roughness factors (Manning’s “n”) used in the hydraulic model were chosen by engineering judgment and are based on field observations and semi-automated methods supported by GIS-based techniques. Table 8 provides a summary of the Manning’s “n” values used in the hydraulic computations for the channel and overbank areas.

TABLE 8 - MANNING'S "N" VALUES Flooding Source Channel “n” Values Overbank “n” Values Basic Creek 0.030 – 0.045 0.050 – 0.090 Black Creek 0.030 0.050 Bozen Kill 0.020 – 0.030 0.050 Tributary 4 to Bozen Kill 0.020 – 0.060 0.030 – 0.100 Tributary 5 to Bozen Kill 0.020 – 0.030 0.050 Coeymans Creek 0.015 – 0.100 0.030 – 0.100 Delphus Kill 0.028 – 0.050 0.035 – 0.065 Eight Mile Creek 0.030 – 0.040 0.060 – 0.120 Feuri Spruyt 0.028 – 0.040 0.060 – 0.120 Hannacrois Creek 0.015 – 0.055 0.040 – 0.150 Tributary 1 to Hannacrois Creek 0.030 – 0.045 0.045 – 0.080 Hudson River 0.030 – 0.050 0.030 – 0.120 Kromma Kill 0.030 – 0.040 0.028 – 0.065 Krum Kill 0.030 – 0.055 0.030 – 0.110 Lisha Kill 0.030 – 0.070 0.028 – 0.090 Tributary 8 to Lisha Kill 0.028 – 0.040 0.030 – 0.060 Mohawk River 0.026 – 0.055 0.030 – 0.100 First Branch Mohawk River 0.028 – 0.055 0.040 – 0.060 Second Branch Mohawk River 0.028 – 0.055 0.040 – 0.060 Third Branch Mohawk River 0.028 – 0.055 0.040 – 0.060 Fifth Branch Mohawk River 0.028 – 0.055 0.040 – 0.060 Normans Kill 0.025 – 0.100 0.030 – 0.100 Tributary 10 to Normans Kill 0.050 – 0.060 0.100 Tributary 1 to Tributary 10 to 0.050 – 0.070 0.110 Normans Kill 0.020 – 0.050 0.030 - 0.050 Patroon Creek 0.018 – 0.055 0.020 – 0.060 Salt Kill 0.032 – 0.040 0.040 – 0.060 Sand Creek 0.028 – 0.055 0.030 – 0.065 Shaker Creek 0.030 – 0.055 0.032 – 0.075 State Basin 0.017 – 0.040 0.045 – 0.075 Vloman Kill 0.030 - 0.050 0.030 - 0.050 Vly Creek 0.020 - 0.030 0.050 – 0.090

45 BASE FLOOD FLOODING SOURCE FLOODWAY WATER SURFACE ELEVATION (FEET NAVD 88) SECTION MEAN WIDTH AREA VELOCITY CROSS SECTION DISTANCE WITHOUT WITH (FEET) (SQUARE (FEET PER REGULATORY FLOODWAY FLOODWAY INCREASE FEET) SECOND) Vloman Kill A -2,1401 322 2,484 1.7 116.9 116.9 117.6 0.7 B -5401 121 835 5.1 117.0 117.0 117.7 0.7 C 7901 292 2,046 1.7 119.7 119.7 120.4 0.7 D 1,6601 170 1,470 2.4 120.0 120.0 120.7 0.7 E 2,7401 217 1,672 2.1 122.3 122.3 123.0 0.7 F 4,9401 173 1,941 1.8 122.6 122.6 123.5 0.9 Vly Creek A 7202 139 424 6.8 126.7 126.53 127.5 1.0 B 2,5002 59 301 9.7 146.0 146.0 146.6 0.6 C 6,2202 34 218 13.3 209.2 209.2 209.8 0.6 D 9,6602 91 557 5.2 295.1 295.1 295.9 0.8 E 12,8202 45 263 9.5 308.8 308.8 309.7 0.9 F 14,7002 72 607 4.1 324.2 324.2 324.2 0.0 G 16,5402 55 386 6.5 326.6 326.6 327.5 0.9 H 17,8302 232 1,741 1.4 330.6 330.6 331.3 0.7 I 20,8602 178 1,030 2.3 333.2 333.2 334.1 0.9 J 24,0402 161 691 2.8 340.7 340.7 341.5 0.8 K 25,4402 181 427 2.0 342.1 342.1 343.0 0.9 L 28,0402 199 320 2.6 344.8 344.8 345.8 1.0 M 31,2402 247 1,096 0.6 350.1 350.1 351.1 1.0 N 34,2402 138 203 3.4 357.2 357.2 358.0 0.8

1 Feet above US Route 9W 3 Elevation computed without consideration of backwater effects from Normans 2 Feet above confluence with Normans Kill Kill

T FEDERAL EMERGENCY MANAGEMENT AGENCY A

B FLOODWAY DATA

L ALBANY COUNTY, NY E (ALL JURISDICTIONS) 1

1 VLOMAN KILL – VLY CREEK

03 – Hydraulic Model

Stewart’s Shops Floodplain Evaluation Voorheesville, Albany County, New York

03 – Hydraulic Model 100-year Floodplain – Existing vs Proposed

Stewart’s Shops Floodplain Evaluation Voorheesville, Albany County, New York

338 Legend

Ground - Comp Geom 5

Ineff - Comp Geom 5 336 Bank Sta - Comp Geom 5

Merge Range

Ground 334 Ineff

Bank Sta

332

) 330 t f ( n o i t a v e l E 328

326

324

322

320 0 100 200 300 400 500 600

Station (ft) 338 Legend

Ground - Comp Geom 5

Ineff - Comp Geom 5 336 Bank Sta - Comp Geom 5

Merge Range

Ground 334 Ineff

Bank Sta

332

) 330 t f ( n o i t a v e l E 328

326

324

322

320 0 100 200 300 400 500 600

Station (ft) HEC-RAS River: VlyCreek Reach: 130P Profile: 100-yr Reach River Sta Profile Plan 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 (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) 130P 1292.232 100-yr EX 2339.00 322.59 332.16 329.40 332.41 0.000582 4.47 624.14 235.95 0.29 130P 1292.232 100-yr PR 2339.00 322.59 332.18 329.40 332.43 0.000573 4.44 627.73 236.91 0.28

130P 1065.649 100-yr EX 2339.00 319.69 332.16 326.22 332.29 0.000249 3.26 873.94 255.92 0.19 130P 1065.649 100-yr PR 2339.00 319.69 332.18 326.22 332.31 0.000246 3.25 878.90 256.53 0.19

130P 976.9742 100-yr EX 2339.00 321.02 332.02 326.35 332.25 0.000332 4.15 932.96 269.12 0.23 130P 976.9742 100-yr PR 2339.00 321.02 332.04 326.35 332.26 0.000329 4.13 938.40 269.91 0.23

130P 936.8258 Bridge

130P 896.6689 100-yr EX 2339.00 320.95 330.66 326.31 331.04 0.000652 5.27 716.04 259.27 0.32 130P 896.6689 100-yr PR 2339.00 320.95 330.71 326.31 331.09 0.000634 5.22 729.91 266.63 0.31

130P 833.1006 100-yr EX 2339.00 320.85 330.73 326.81 330.91 0.000400 3.81 1078.47 342.76 0.24 130P 833.1006 100-yr PR 2339.00 320.85 330.78 326.81 330.95 0.000387 3.76 1096.23 344.26 0.24

130P 732.5337 100-yr EX 2339.00 320.52 330.71 326.61 330.86 0.000413 3.95 938.00 158.38 0.24 130P 732.5337 100-yr PR 2339.00 320.52 330.59 326.73 330.89 0.000699 5.10 675.41 116.14 0.31

130P 614.4185 100-yr EX 2339.00 320.18 330.54 326.84 330.79 0.000583 5.09 1126.91 341.81 0.30 130P 614.4185 100-yr PR 2339.00 320.18 330.49 326.81 330.81 0.000678 5.47 909.56 221.11 0.32

130P 506.0436 100-yr EX 2339.00 319.51 330.61 325.59 330.71 0.000234 3.34 1567.44 238.21 0.19 130P 506.0436 100-yr PR 2339.00 319.51 330.61 325.59 330.71 0.000234 3.34 1567.44 238.21 0.19

130P 388.1439 100-yr EX 2339.00 319.72 330.60 325.47 330.67 0.000201 3.12 2242.89 520.77 0.18 130P 388.1439 100-yr PR 2339.00 319.72 330.60 325.47 330.67 0.000201 3.12 2242.89 520.77 0.18 Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 VlyCreek 130P 334 Legend

WS 100-yr - EX

WS 100-yr - PR

332 Ground

LOB

ROB 330

328 ) t f ( n o i t 326 a v e l E

324

322

320

318 0 200 400 600 800 1000

Main Channel Distance (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 1292.232 Begin Geometry, Blocked Obs in Rt OB (Elementary School), Rt Ine .02 .03 .02 355 Legend

WS 100-yr - PR

WS 100-yr - EX

350 2.5 ft/s 3.0 ft/s

3.5 ft/s

4.0 ft/s 345 4.5 ft/s

Ground

Ineff

340 Bank Sta ) t f ( n o i t a v e l E 335

330

325

320 0 100 200 300 400 500 600 700

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 1065.649 Appr Route 85A, Ineffective from Route 85A (See GeoRAS), Blocked .02 .03 .02 360 Legend

WS 100-yr - PR

WS 100-yr - EX

1.0 ft/s

1.5 ft/s 350 2.0 ft/s

2.5 ft/s

3.0 ft/s

3.5 ft/s

Ground 340 Ineff ) t f ( Bank Sta n o i t a v e l E

330

320

310 0 100 200 300 400 500 600 700

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 976.9742 USF Route 85A, Ineffectives from Route 85A (See GeoRAS), Channel .05 .03 .05 350 Legend

WS 100-yr - PR

WS 100-yr - EX

0 ft/s 345 1 ft/s

2 ft/s

3 ft/s

4 ft/s

340 5 ft/s

Ground

Ineff ) t f ( Bank Sta n o i t 335 a v e l E

330

325

320 0 100 200 300 400 500

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 936.8258 BR Route 85A (Maple Ave); .05 .03 .05 350 Legend

WS 100-yr - PR

WS 100-yr - EX

2 ft/s 345 3 ft/s

4 ft/s

5 ft/s

6 ft/s

340 7 ft/s

Ground

Ineff ) t f ( Bank Sta n o i t 335 a v e l E

330

325

320 0 100 200 300 400 500

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 936.8258 BR Route 85A (Maple Ave); .05 .03 .08 355 Legend

WS 100-yr - PR

WS 100-yr - EX

350 1 ft/s 2 ft/s

3 ft/s

4 ft/s 345 5 ft/s

6 ft/s

7 ft/s

340 Ground ) t f ( Ineff n o i t

a Bank Sta v e l E 335

330

325

320 0 100 200 300 400 500

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 896.6689 DSF Route 85A, Ineffectives from Route 85A, Blocked Obs in Rt OB .05 .03 .08 355 Legend

WS 100-yr - PR

WS 100-yr - EX

350 0 ft/s 1 ft/s

2 ft/s

3 ft/s 345 4 ft/s

5 ft/s

6 ft/s

340 Ground ) t f ( Ineff n o i t

a Bank Sta v e l E 335

330

325

320 0 100 200 300 400 500

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 833.1006 Exit Route 85A, Ineffectives from Route 85A, Blocked Obs in Rt O .05 .03 .08 355 Legend

WS 100-yr - PR

WS 100-yr - EX

350 0 ft/s 1 ft/s

2 ft/s

3 ft/s 345 4 ft/s

Ground

Ineff

340 Bank Sta ) t f ( n o i t a v e l E 335

330

325

320 0 100 200 300 400 500

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 732.5337 Ineffective from Route 85A (See GeoRAS), Blocked Obs in Lt OB (S .05 .03 .08 355 Legend

WS 100-yr - EX

WS 100-yr - PR

350 0 ft/s 1 ft/s

2 ft/s

3 ft/s 345 4 ft/s

Ground

Ineff

340 Bank Sta ) t f ( n o i t a v e l E 335

330

325

320 0 100 200 300 400 500 600

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 614.4185 Ineffective from Route 85A (See GeoRAS), Channel Surveyed, Topo .05 .03 .08 338 Legend

WS 100-yr - EX

WS 100-yr - PR 336 0 ft/s

1 ft/s

334 2 ft/s 3 ft/s

4 ft/s

332 5 ft/s

6 ft/s

Ground )

t 330 f ( Ineff n o i t

a Bank Sta v e l

E 328

326

324

322

320 0 100 200 300 400 500 600

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 506.0436 Blocked Obs in Lt and Rt OB's (Houses, See GeoRAS), Channel Surv .08 .03 .08 360 Legend

WS 100-yr - EX

WS 100-yr - PR 355 0.5 ft/s

1.0 ft/s

350 1.5 ft/s 2.0 ft/s

2.5 ft/s

345 3.0 ft/s

3.5 ft/s

Ground )

t 340 f ( Bank Sta n o i t a v e l

E 335

330

325

320

315 0 100 200 300 400 500 600 700

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX 1/9/2017 2) PR 1/9/2017 RS = 388.1439 End Geometry; FIS XS 'H'; Channel Surveyed, .08 .03 .08 338 Legend

WS 100-yr - EX

336 WS 100-yr - PR 0.5 ft/s

1.0 ft/s 334 1.5 ft/s

2.0 ft/s

332 2.5 ft/s

3.0 ft/s

3.5 ft/s 330 Ground ) t f ( Bank Sta n o i t 328 a v e l E

326

324

322

320

318 0 100 200 300 400 500 600 700 800

Station (ft)

03 – Hydraulic Model 100-year Floodway – Existing vs Proposed

Stewart’s Shops Floodplain Evaluation Voorheesville, Albany County, New York

HEC-RAS River: VlyCreek Reach: 130P Profile: 100-yr Fldwy Reach River Sta Profile Plan 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 (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) 130P 1292.232 100-yr Fldwy EX - Fldwy 2339.00 322.59 333.02 329.40 333.20 0.000323 3.58 713.60 142.37 0.22 130P 1292.232 100-yr Fldwy PR - Fldwy 2339.00 322.59 333.02 329.40 333.20 0.000323 3.58 713.60 142.37 0.22

130P 1065.649 100-yr Fldwy EX - Fldwy 2339.00 319.69 332.88 326.21 333.11 0.000335 3.98 615.51 77.73 0.22 130P 1065.649 100-yr Fldwy PR - Fldwy 2339.00 319.69 332.88 326.21 333.11 0.000335 3.98 615.51 77.73 0.22

130P 976.9742 100-yr Fldwy EX - Fldwy 2339.00 321.02 332.86 326.33 333.08 0.000276 3.99 741.31 82.18 0.21 130P 976.9742 100-yr Fldwy PR - Fldwy 2339.00 321.02 332.86 326.33 333.08 0.000276 3.99 741.31 82.18 0.21

130P 936.8258 Bridge

130P 896.6689 100-yr Fldwy EX - Fldwy 2339.00 320.95 331.42 326.31 331.71 0.000450 4.64 718.16 113.23 0.27 130P 896.6689 100-yr Fldwy PR - Fldwy 2339.00 320.95 331.42 326.31 331.71 0.000450 4.64 718.16 113.23 0.27

130P 833.1006 100-yr Fldwy EX - Fldwy 2339.00 320.85 331.42 326.67 331.66 0.000414 4.10 736.75 114.58 0.25 130P 833.1006 100-yr Fldwy PR - Fldwy 2339.00 320.85 331.42 326.67 331.66 0.000414 4.10 736.75 114.58 0.25

130P 732.5337 100-yr Fldwy EX - Fldwy 2339.00 320.52 331.31 326.76 331.60 0.000601 4.99 676.61 100.99 0.29 130P 732.5337 100-yr Fldwy PR - Fldwy 2339.00 320.52 331.31 326.76 331.60 0.000600 4.99 676.33 100.99 0.29

130P 614.4185 100-yr Fldwy EX - Fldwy 2339.00 320.18 331.18 326.83 331.52 0.000626 5.51 798.55 123.12 0.31 130P 614.4185 100-yr Fldwy PR - Fldwy 2339.00 320.18 331.18 326.79 331.52 0.000626 5.51 798.55 123.12 0.31

130P 506.0436 100-yr Fldwy EX - Fldwy 2339.00 319.51 331.30 325.71 331.42 0.000239 3.54 1328.89 164.94 0.19 130P 506.0436 100-yr Fldwy PR - Fldwy 2339.00 319.51 331.30 325.71 331.42 0.000239 3.54 1328.89 164.94 0.19

130P 388.1439 100-yr Fldwy EX - Fldwy 2339.00 319.72 331.30 325.51 331.38 0.000178 3.08 1754.71 238.65 0.17 130P 388.1439 100-yr Fldwy PR - Fldwy 2339.00 319.72 331.30 325.51 331.38 0.000178 3.08 1754.71 238.65 0.17 Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 VlyCreek 130P 334 Legend

WS 100-yr Fldwy - EX - Fldwy

WS 100-yr Fldwy - PR - Fldwy

332 Ground

LOB

ROB 330

328 ) t f ( n o i t 326 a v e l E

324

322

320

318 0 200 400 600 800 1000

Main Channel Distance (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 1292.232 Begin Geometry, Blocked Obs in Rt OB (Elementary School), Rt Ine .02 .03 .02 355 Legend

WS 100-yr Fldwy - EX - Fldwy

WS 100-yr Fldwy - PR - Fldwy

350 2.8 ft/s 3.0 ft/s

3.2 ft/s

3.4 ft/s 345 3.6 ft/s

Ground

Ineff

340 Bank Sta ) t f ( Encroachment n o i t a v e l E 335

330

325

320 0 100 200 300 400 500 600 700

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 1065.649 Appr Route 85A, Ineffective from Route 85A (See GeoRAS), Blocked .02 .03 .02 360 Legend

WS 100-yr Fldwy - EX - Fldwy

WS 100-yr Fldwy - PR - Fldwy

2.0 ft/s

2.5 ft/s 350 3.0 ft/s

3.5 ft/s

4.0 ft/s

Ground

Ineff 340 Bank Sta ) t f ( Encroachment n o i t a v e l E

330

320

310 0 100 200 300 400 500 600 700

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 976.9742 USF Route 85A, Ineffectives from Route 85A (See GeoRAS), Channel .05 .03 .05 350 Legend

WS 100-yr Fldwy - EX - Fldwy

WS 100-yr Fldwy - PR - Fldwy

1.0 ft/s 345 1.5 ft/s

2.0 ft/s

2.5 ft/s

3.0 ft/s

340 3.5 ft/s

4.0 ft/s

Ground ) t f ( Ineff n o i t 335

a Bank Sta v e l

E Encroachment

330

325

320 0 100 200 300 400 500

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 936.8258 BR Route 85A (Maple Ave); .05 .03 .05 350 Legend

WS 100-yr Fldwy - EX - Fldwy

WS 100-yr Fldwy - PR - Fldwy

2 ft/s 345 3 ft/s

4 ft/s

5 ft/s

6 ft/s

340 7 ft/s

Ground

Ineff ) t f ( Bank Sta n o i t 335

a Encroachment v e l E

330

325

320 0 100 200 300 400 500

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 936.8258 BR Route 85A (Maple Ave); .05 .03 .08 355 Legend

WS 100-yr Fldwy - EX - Fldwy

WS 100-yr Fldwy - PR - Fldwy

350 0 ft/s 2 ft/s

4 ft/s

6 ft/s 345 8 ft/s

Ground

Ineff

340 Bank Sta ) t f ( Encroachment n o i t a v e l E 335

330

325

320 0 100 200 300 400 500

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 896.6689 DSF Route 85A, Ineffectives from Route 85A, Blocked Obs in Rt OB .05 .03 .08 355 Legend

WS 100-yr Fldwy - EX - Fldwy

WS 100-yr Fldwy - PR - Fldwy

350 0 ft/s 1 ft/s

2 ft/s

3 ft/s 345 4 ft/s

5 ft/s

Ground

340 Ineff ) t f ( Bank Sta n o i t

a Encroachment v e l E 335

330

325

320 0 100 200 300 400 500

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 833.1006 Exit Route 85A, Ineffectives from Route 85A, Blocked Obs in Rt O .05 .03 .08 355 Legend

WS 100-yr Fldwy - EX - Fldwy

WS 100-yr Fldwy - PR - Fldwy

350 0 ft/s 1 ft/s

2 ft/s

3 ft/s 345 4 ft/s

5 ft/s

Ground

340 Ineff ) t f ( Bank Sta n o i t

a Encroachment v e l E 335

330

325

320 0 100 200 300 400 500

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 732.5337 Ineffective from Route 85A (See GeoRAS), Blocked Obs in Lt OB (S .05 .03 .08 355 Legend

WS 100-yr Fldwy - PR - Fldwy

WS 100-yr Fldwy - EX - Fldwy

350 0 ft/s 1 ft/s

2 ft/s

3 ft/s 345 4 ft/s

5 ft/s

Ground

340 Ineff ) t f ( Bank Sta n o i t

a Encroachment v e l E 335

330

325

320 0 100 200 300 400 500 600

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 614.4185 Ineffective from Route 85A (See GeoRAS), Channel Surveyed, Topo .05 .03 .08 338 Legend

WS 100-yr Fldwy - EX - Fldwy

WS 100-yr Fldwy - PR - Fldwy 336 1 ft/s

2 ft/s

334 3 ft/s 4 ft/s

5 ft/s

332 6 ft/s

Ground

Ineff )

t 330 f ( Bank Sta n o i t

a Encroachment v e l

E 328

326

324

322

320 0 100 200 300 400 500 600

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 506.0436 Blocked Obs in Lt and Rt OB's (Houses, See GeoRAS), Channel Surv .08 .03 .08 360 Legend

WS 100-yr Fldwy - EX - Fldwy

WS 100-yr Fldwy - PR - Fldwy 355 0.5 ft/s

1.0 ft/s

350 1.5 ft/s 2.0 ft/s

2.5 ft/s

345 3.0 ft/s

3.5 ft/s

4.0 ft/s )

t 340 f ( Ground n o i t

a Bank Sta v e l

E 335 Encroachment

330

325

320

315 0 100 200 300 400 500 600 700

Station (ft) Stewarts_Shops_Vly_Creek Plan: 1) EX - Fldwy 1/9/2017 2) PR - Fldwy 1/9/2017 RS = 388.1439 End Geometry; FIS XS 'H'; Channel Surveyed, .08 .03 .08 338 Legend

WS 100-yr Fldwy - EX - Fldwy

336 WS 100-yr Fldwy - PR - Fldwy 0.5 ft/s

1.0 ft/s 334 1.5 ft/s

2.0 ft/s

332 2.5 ft/s

3.0 ft/s

3.5 ft/s 330 Ground ) t f ( Bank Sta n o i t 328

a Encroachment v e l E

326

324

322

320

318 0 100 200 300 400 500 600 700 800

Station (ft)