Determining Peak Flow Under Different Scenarios and Identifying Undersized Culverts

Size: px

Start display at page:

Download "Determining Peak Flow Under Different Scenarios and Identifying Undersized Culverts"

Owen Holt
6 years ago
Views:

Determining Peak Flow Under Different Scenarios and Identifying Undersized s Dr. Todd Walter, Biological and Environmental Engineering, Cornell University Dr.

1 Determining Peak Flow Under Different Scenarios and Identifying Undersized s Dr. Todd Walter, Biological and Environmental Engineering, Cornell University Dr. Art DeGaetano, Earth and Atmospheric Sciences, Cornell University, and Northeast Regional Climate Center Andrew Meyer, Hudson River Estuary Program and NYS WRI Rebecca Marjerison, Ph.D. student, Biological and Environmental Engineering, Cornell University Objectives The overall objective of this project was to identify undersized culverts, for both current and future precipitation conditions. Undersized culverts often present increased risks of wash-outs or overtopping during storms, which can present safety risks in communities. Having the information necessary to upsize culverts proactively can allow communities to improve their climate resilience. The specific objectives were to determine the capacity of culverts within the study watersheds, calculate the peak storm discharge at each culvert for current and future precipitation conditions and compare runoff to capacity to identify culverts that are currently undersized, and those which are likely to be undersized in the future. An online culvert-capacity calculator was also to be developed. Background Road culverts are ubiquitous and have traditionally been designed for maximum efficiency, i.e., the smallest culvert that can accommodate the design flow. Of course, this approach is driven largely by economic considerations smaller culverts cost less than big ones. Unfortunately, landscapes and climate are dynamic. Trends in recent decades are likely in the direction of increasing peak storm flows, and appear likely to continue to increase for the foreseeable future. If peak storm runoff rates increase then existing culverts could become undersized. Similar problems may arise regionally if current trends towards more frequent highintensity rainfall persist (e.g., Degaetano 2009). In addition to the potential problems with the capacity of culverts to accommodate future storm flows, culverts are very often identified as barriers to aquatic organisms (e.g., Meixler et al. 2009). Small culverts accelerate stream flows, which increases erosion below the culvert so that a drop develops immediately below the culvert. Identifying places in a drainage network where culverts are undersized has important implications for infrastructure and ecosystems and will help planners target culverts that need immediate modifications for the short term and for future conditions. Methods Three study watersheds were chosen within the Hudson River estuary watershed: Woodbury Creek in Orange County, Saw Kill in Dutchess County, and Hollowville Creek in Columbia County. Staff from New York State Department of Environmental Conservation (NYSDEC) and county Soil and Water Conservation Districts (SWCD) drove all the public roads in the watershed and collected data on culverts under or close to the roads in each sample watershed. Measurements of diameter, slope, length and other dimensions were taken (see Appendix for field sheet). The location of each culvert was recorded by GPS. Photos were taken of the inlet, outlet, and surrounding areas. Perched culvert outlets and drops into culverts were recorded to give an understanding of aquatic passage concerns in each watershed. Combining undersized culverts modeled from this project with those that are also barriers to aquatic organisms could lead to strong candidates in grant applications. When the field data collection was complete, the information was sent to the Cornell team for analysis. Standard engineering equations using size, shape, inlet type, length, slope, and material were used to calculate peak runoff capacity for each culvert. Certain assumptions were necessary to perform the analyses.

2 It was assumed that at maximum capacity a culvert inlet would be submerged, with the water just to the top of the road but not spilling over. The outlet condition could not be determined without more information about downstream conditions, so the capacities for both submerged and conditions were calculated. Where a culvert was listed as being arch-shaped, it was assumed to be half an ellipse. Precipitation depths for the 24 hour storm for both present and future conditions were obtained for each study watershed from the Northeast Regional Climate Center (NRCC). Nine return periods were considered: 1, 2, 5, 10, 25, 50, 100, 200, and 500 years. Average precipitation depths for each study watershed were calculated for each return period, and all storms were assumed to be uniform in space and time. The drainage area, time of concentration, land use and soil characteristics of each culvert were determined using ArcGIS tools. The USDA National Resources Conservation Service (NRCS, formerly Soil Conservation Service, SCS) TR-55 Graphical Peak Discharge Method (USDA 1986) was used to calculate peak storm runoff for each culvert. This method accounts for the small size of the culvert drainage areas. Peak runoff was calculated for both present and predicted future conditions. For the purposes of calculating drainage area, each point representing a culvert location was moved to the pixel with the largest drainage area within 15 meters. In some cases, points were moved individually, using orthophotos and photos from the field, to align them with the modeled flow paths. The capacity of each culvert was compared to the peak runoff values at the culvert to determine the maximum return period that could be accommodated. A separate maximum return period was calculated for the predicted future peak runoff values. A web-based tool for determining runoff for various sized storms was developed. The tool uses information in the NRCC precipitation database, land use and soil data, and elevation data. The runoff model is the same as above, and is applied to a drainage area defined interactively by the user. The time of concentration is calculated differently in this implementation: the longest flow path and slope are based on the geometry of the user s chosen area of interest. Results The distribution of return periods associated with the peak runoff capacity of culverts varied by study watershed (Fig. 1) and by road ownership (Fig 2). For example, in the Hollowville Creek watershed, over 50% of the culverts had return periods less than the 1 year storm, whereas fewer than 25% of the culverts in Woodbury Creek were in the less than 1 year category. In all three watersheds, state-owned roads tended to have longer return periods than town or county-owned roads. Color-coded maps of culvert locations and return periods were prepared as guides for the county and town officials (Fig. 3). The web tool is currently capable of determining runoff for nine predefined return periods for current and future precipitation regimes (Fig. 4). The tool was demonstrated for a diverse audience on December 2, 2013, and was well received. Several improvements were suggested or requested by meeting participants. The tool will be available soon for public use and comment. Runoff calculations could be improved by surveying drainage area boundaries and measuring the slope of the landscape with more accuracy. The flow type in a culvert can be determined by measuring the slope and channel shape downstream of the culvert. These improved measurements would lead to a better understanding of the culvert capacity and the peak runoff from a given storm. Acknowledgements This publication was prepared for NYS Water Resources Institute and the NYS Department of Environmental Conservation Hudson River Estuary Program, with support from the NYS Environmental Protection Fund.

3 Return period of peak runoff capacity (yr) Return period of peak runoff capacity (yr) Return period of peak runoff capacity (yr) 3% 7% 3% 3% 5% Hollowville Creek (Columbia County ) 5% < % 0% 3% 9% 0% Saw Kill (Dutchess County) 7% 32% < % 10% 5% 56% % 17% 18% % 12% 5% 0% 21% 10% Woodbury Creek (Orange County) < 1 23% 15% 3% 9% Figure 1. Percentage distribution of return period of culvert peak flow capacity () for each study watershed.

4 Number of s private town county state private town county state town county state Hollowville Creek Saw Kill Woodbury Creek Figure 2. Distribution of return period of culvert peak flow capacity (), displayed by road ownership and watershed.

7 Figure 3. Map of culverts color-coded by current return period of peak flow capacity (). s with black outlines are expected to have a shorter return period in the 2050 precipitation regime.

8 Figure 4. Screenshot of runoff calculator web tool. The drainage area polygon on the left was defined interactively using the topographic lines on the map. The chart on the right is the output generated when the Calculate Runoff button is clicked.

9 Appendix A. capacities The peak flow capacity of each culvert was calculated using a mechanistic pipe flow equation: a 2gH q = 1 + K e + K c l Eqn. 1 where q is the flow rate, a is the pipe cross-sectional area, H is the energy head, K e is the entrance loss coefficient (table 1), K c is the pipe frictional loss coefficient (table 2), and L is the pipe length. Peak flow capacity was calculated for submerged and conditions. The energy head, H, is defined differently for the two conditions: Submerged Unsubmerged H 1 = ls H 2 = ls D where l is culvert length, s is culvert slope (percent), and D is culvert diameter. Table 1. Entrance loss coefficients used for calculating culvert peak flow capacity. Adapted from Inlet K e Shape Type Arch Concrete Headwall 0.5 Mitered 0.7 Wingwall 0.5 Metal Headwall 0.5 Mitered 0.7 Projecting 0.9 Box Concrete Headwall 0.5 Wingwall 0.5 Plastic Headwall 0.5 Circular/Oval Concrete Headwall 0.5 Projecting 0.5 Wingwall 0.2 Metal Headwall 0.5 Projecting 0.9 Mitered 0.7 Wingwall 0.5 Plastic Headwall 0.5 Mitered 0.7 Projecting 0.9 Wingwall 0.5

Table 2. Head loss coefficients used for calculating culvert peak flow capacity. Bottom material Manning's n Concrete 0.010 Metal 0.025 Plastic 0.020 Stream Bed Boulder 0.050 Gravel 0.023 Rock 0.

10 Table 2. Head loss coefficients used for calculating culvert peak flow capacity. Bottom material Manning's n Concrete Metal Plastic Stream Bed Boulder Gravel Rock Silt The loss coefficient (K c ) for round culverts was calculated as: n2 K c = 3.28 D 4 3 where n is Manning s n and d is culvert diameter. For square culverts: 19.6 n2 K c = 3.28 R 4 3 where R is the hydraulic radius. The perimeter of the culvert was used as the hydraulic radius since the assumption was a culvert running full. B. Drainage area characteristics Drainage area characteristics were calculated in ArcGIS using a digital elevation model (DEM) from the USGS National Elevation Dataset (Gesch et al 2002, Gesch 2007). The DEM was projected into the Universal Transverse Mercator projection, Zone 18, North American Datum The projection used a bilinear resampling method and a 10 meter cell size. The watershed delineation process used built-in ArcGIS tools to determine a drainage area for each culvert (Fig. 5). The average slope and longest flow path of each drainage area were also calculated with ArcGIS tools (Slope and Flow Length, respectively). ArcGIS tool chain for delineating drainage areas for each culvert. Figure 5.

11 C. Runoff Runoff amounts for various storm depths were calculated using the Curve Number method (USDA 1986). Time of concentration was calculated with a modified Kirpich (1940) method: t c = L 0.77 S Eqn. 2 where t c is time of concentration, L is the longest flow path in the drainage area, and S is the average slope of the drainage area Average curve number for each culvert drainage area was calculated from a 30 meter raster derived from National Land Cover Database 2006 land use data (Fry et al. 2011) and State Soil Geographic Database (STATSGO) soil data (USDA 2010). Curve numbers were based on TR-55 tabulated values (Table 4). Hydrologic soil group was assumed be to D wherever two values were listed in the soil database. If a range of curve numbers was provided, a central value was selected as representative of that land use/soil combination. The average storage for a drainage area was calculated based on the average curve number for that drainage. Storage is calculated as: S = Eqn. 3 CN where S is storage (cm) and CN is average curve number. Runoff depth, Q, for the whole storm is then calculated as: Q = (P 0.2S)2 P + 0.8S Eqn. 4 where P is precipitation depth (cm). Precipitation depths were derived from the NRCC extreme precipitation database, and an average value was calculated for each study watershed (table 3). The peak runoff, q peak, for a given storm over a given drainage area was calculated with the graphical unit hydrograph method: q peak = q u AQ Eqn. 5 where, q peak is the peak runoff (m 3 s -1 ), q u is a unitless adjustment factor, A is the drainage area (km 2 ), and Q (cm) is the total runoff depth, calculated in Equation 4. The adjustment factor, q u, is calculated as: log(q u ) = C 0 + C 1 log(t c ) + C 2 [log (t c )] 2 Eqn. 6 C o, C 1, and C 2 are constants that are functions of rain ratio and rainfall type. These constants are tabulated in the TR-55 method, but for this analysis a curve-fit polynomial expression was used to calculate interpolated constants for each drainage area (Eqns. 7-9). Rain ratio is defined as I a where Ia is the initial abstraction, or the amount of precipitation that does not become runoff. Rainfall Type II was assumed, because that is applicable to most of New York State. P

12 C 0 = ( I a P ) I a P C 1 = ( I a P ) I a P C 2 = ( I a P ) I a P Eqn. 7 Eqn. 8 Eqn. 9 The q peak value for each return period was compared to the previously calculated culvert capacities. The maximum return period with a q peak less than the culvert capacity was considered the return period of that culvert. Table 3. Precipitation depths used for runoff calculations (cm). Present precipitation amounts were obtained from Northeast Regional Climate Center (NRCC). Future precipitation amounts were estimated at 10% above present values, based on NRCC models. Return Period 1yr 2yr 5yr 10yr 25 yr 50 yr 100yr 200yr 500yr Hollowville Cr. Present Saw Kill Present Woodbury Cr. Present

13 Table 4. Curve numbers for land use-soil group combinations. Adapted from USDA-NRCS (formerly SCS) Technical Report 55. LU code land use Soil CN 11 Water A, B, C, D 0 21 Developed, open space A 46 B 65 C 77 D Developed, low intensity A 56 B 71 C 81 D Developed, medium intensity A 77 B 85 C 90 D Developed, high intensity A 89 B 92 C 94 D Deciduous forest A 36 B 60 C 73 D Evergreen forest A 36 B 60 C 73 D Mixed forest A 36 B 60 C 73 D Shrub land A 35 B 56 C 70 D Grassland A 30 B 58 C 71 D Pasture A 49 B 69 C 79 D Row crops A 72 B 81 C 88 D Woody wetlands A, B, C, D 0

14 Barrier Submerged Unsubmerged CC CC CC <1 <1 <1 <1 CC CC <1 <1 <1 <1 CC CC CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 1 <1 <1 CC CC CC <1 1 <1 1 CC CC <1 <1 <1 <1 CC CC CC <1 1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC

15 Barrier Submerged Unsubmerged CC <1 <1 <1 <1 CC CC CC CC CC CC <1 <1 <1 <1 CC CC CC <1 1 <1 1 CC CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 1 CC CC <1 1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 1 <1 <1 CC <1 <1 <1 <1 CC CC

16 Barrier Submerged Unsubmerged CC <1 2 <1 1 CC CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC CC CC CC CC <1 <1 <1 <1 CC <1 1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 CC <1 <1 <1 <1 DC DC DC <1 1 <1 <1 DC DC <1 <1 <1 <1 DC DC <1 <1 <1 <1 DC <1 <1 <1 <1 DC DC <1 <1 <1 <1 DC

17 Barrier Submerged Unsubmerged DC DC DC DC DC DC DC <1 <1 <1 <1 DC <1 <1 <1 <1 DC <1 <1 <1 <1 DC DC DC DC <1 <1 <1 <1 DC DC DC DC DC DC DC DC <1 <1 DC DC <1 <1 <1 <1 DC <1 <1 <1 <1 DC <1 1 <1 <1 DC DC DC

18 Barrier Submerged Unsubmerged DC DC DC DC <1 <1 DC DC DC <1 <1 <1 <1 DC DC <1 1 DC DC DC DC <1 <1 <1 <1 DC DC DC <1 1 DC DC <1 1 DC <1 <1 DC DC <1 <1 DC <1 <1 <1 <1 DC <1 <1 <1 <1 DC DC DC <1 <1 <1 <1 DC <1 <1 <1 <1 DC

19 Barrier Submerged Unsubmerged DC <1 <1 DC DC DC DC DC DC <1 1 <1 <1 DC <1 <1 <1 <1 DC <1 <1 DC DC <1 <1 <1 <1 DC <1 1 <1 <1 DC <1 <1 <1 <1 DC DC DC <1 <1 <1 <1 DC <1 1 <1 <1 DC <1 <1 <1 <1 DC DC <1 <1 <1 <1 DC DC DC <1 <1 <1 <1 DC DC DC <1 <1 <1 <1 DC <1 1 DC

20 Barrier Submerged Unsubmerged DC <1 <1 <1 <1 DC <1 <1 <1 <1 DC DC <1 <1 <1 <1 DC <1 <1 <1 <1 DC DC DC DC DC DC DC DC <1 <1 <1 <1 DC <1 <1 <1 <1 DC <1 <1 <1 <1 DC DC DC <1 <1 DC DC <1 1 DC DC DC DC <1 <1 <1 <1 DC DC OC OC

21 Barrier Submerged Unsubmerged OC OC OC OC OC OC OC OC OC OC OC <1 <1 <1 <1 OC <1 <1 <1 <1 OC <1 <1 <1 <1 OC <1 <1 <1 <1 OC OC OC OC OC OC OC OC OC OC OC OC OC OC <1 <1 <1 <1

22 Barrier Submerged Unsubmerged OC OC OC <1 5 <1 5 OC OC OC OC OC OC OC OC OC <1 <1 OC OC OC OC OC <1 5 <1 5 OC <1 500 <1 500 OC <1 1 <1 <1 OC <1 <1 <1 <1 OC <1 <1 <1 <1 OC OC <1 <1 <1 <1 OC OC <1 <1 <1 <1 OC <1 <1 <1 <1 OC <1 1 <1 1 OC

23 Barrier Submerged Unsubmerged OC OC OC OC OC OC OC OC <1 500 <1 500 OC OC OC OC OC OC <1 500 <1 500 OC <1 <1 <1 <1 OC <1 500 <1 500 OC OC OC OC OC OC OC OC OC OC OC OC

24 Barrier Submerged Unsubmerged OC <1 500 <1 500 OC <1 <1 <1 <1 OC OC OC OC OC OC

25 Table 5. properties used for calculation of culvert capacity. Measurements were collected June through August, Barrier Latitude Longitude Shape Length (ft) Dimensions (in) Inlet Type Bottom Slope Stream Bed Ownership CC Circular Plastic Headwall 2.6% Silt Town CC Arch x 20 Concrete Mitered 9.8% Gravel Town CC Circular Metal Projecting 3.2% Silt Town CC Circular Metal Wingwall 5.0% Silt Town CC Circular Plastic Projecting 6.8% Rock Town CC Box x 29 Concrete Headwall Stream 9.4% Silt State CC Circular Plastic Projecting 2.6% Rock State CC Arch x 36 Metal Mitered 7.5% Rock State CC Circular Metal Projecting 6.9% Gravel Town CC Box x 84 Concrete Wingwall Stream 1.1% Gravel State CC Box x 54 Concrete Wingwall Stream 1.9% Rock State CC Circular Plastic Headwall 5.2% Gravel Town CC Circular Plastic Headwall 2.2% Gravel Town CC Circular Plastic Headwall 0.8% Gravel Town CC Circular Metal Projecting 0.6% Silt Town CC Circular Plastic Headwall 1.3% Rock Town CC Circular Plastic Headwall 8.1% Gravel Town CC Arch x 72 Metal Mitered 4.2% Rock Town CC Circular Concrete Projecting 4.0% Rock Private CC Circular Concrete Headwall 3.0% Rock Town CC Circular Plastic Headwall 1.4% Rock County CC Circular Plastic Headwall 2.0% Gravel Town CC Circular Plastic Headwall 3.6% Rock Town CC Circular Plastic Headwall 7.8% Gravel Town CC Box x 48 Concrete Wingwall 0.9% Rock Town CC Circular Plastic Headwall 3.3% Gravel Town CC Oval x 72 Metal Headwall 0.7% Rock Town CC Box x 28 Concrete Headwall 2.3% Rock County

26 Barrier Latitude Longitude Shape Length (ft) Dimensions (in) Inlet Type Bottom Slope Stream Bed Ownership CC Box x 66 Concrete Headwall Stream 1.2% Rock State CC Circular Concrete Headwall 0.9% Rock County CC Arch x 24 Metal Headwall Stream 8.3% Gravel Town CC Circular Plastic Headwall 2.9% Gravel Town CC Circular Metal Projecting 2.5% Silt State CC Box x 40 Concrete Headwall Stream 0.6% Gravel Town CC Circular Metal Headwall 1.1% Rock State CC Arch x 120 Concrete Wingwall Stream 3.9% Rock County CC Box x 30 Concrete Headwall Stream 0.8% Rock County CC Box x 96 Concrete Headwall Stream 0.7% Boulder County CC Box x 66 Concrete Wingwall Stream 1.2% Rock Town CC Oval x 54 Metal Headwall 6.4% Rock Town CC Circular Plastic Headwall 3.5% Gravel Town CC Arch x 33 Metal Headwall 4.2% Rock Private CC Box x 48 Concrete Wingwall 0.8% Boulder Town CC Circular Metal Projecting 17.3% Rock Town CC Circular Metal Headwall 4.9% Rock Town CC Circular Metal Headwall 8.5% Gravel Town CC Box x 72 Concrete Wingwall Stream 0.6% Rock Town CC Box x 36 Concrete Wingwall Stream 0.5% Silt State CC Circular Metal Headwall 0.5% Gravel State CC Circular Metal Headwall 3.4% Gravel Town CC Circular Concrete Headwall 3.0% Rock State CC Circular Plastic Headwall 6.6% Silt Town CC Box x 40 Concrete Wingwall Stream 1.3% Rock Town CC Box x 38 Concrete Wingwall Stream 0.8% Rock Town CC Circular Concrete Projecting 1.8% Gravel County CC Circular Concrete Headwall 6.7% Gravel County CC Circular Concrete Headwall 1.4% Gravel County CC Circular Concrete Headwall 1.3% Silt County

27 Barrier Latitude Longitude Shape Length (ft) Dimensions (in) Inlet Type Bottom Slope Stream Bed Ownership CC Circular Plastic Projecting 5.2% Gravel Town CC Arch x 44 Metal Projecting 0.9% Silt County CC Circular Metal Projecting 7.4% Gravel Town CC Circular Plastic Headwall 5.7% Gravel Town CC Circular Plastic Headwall 2.3% Gravel Town CC Circular Plastic Headwall 7.7% Gravel Town CC Circular Plastic Headwall 2.4% Gravel Town CC Circular Plastic Headwall 2.8% Gravel Town CC Circular Plastic Headwall 1.4% Gravel Town CC Circular Plastic Headwall 1.5% Silt Town CC Circular Plastic Headwall 1.5% Silt Town CC Circular Plastic Headwall 1.2% Gravel Town CC Circular Plastic Headwall 3.3% Gravel Town CC Circular Metal Headwall 0.8% Gravel Town CC Circular 1 18 Plastic Headwall 2.2% Gravel Town DC Circular Metal Wingwall 3.0% Silt State DC Circular Metal Wingwall 1.5% Silt State DC Circular Concrete Other 0.8% Silt County DC Box X 26 Concrete Headwall Stream 5.2% Silt County DC Circular Plastic Projecting 1.3% Silt Town DC Arch X 50 Other Headwall Stream 1.4% Rock Other DC Circular 8 21 Metal Projecting 1.9% Gravel Town DC Circular 8 21 Metal Projecting 1.9% Gravel Town DC Circular Plastic Projecting 3.0% Silt County DC Circular Plastic Wingwall 10.7% Gravel Town DC Box X 21 Concrete Headwall Stream 1.5% Silt State DC Box X 40 Concrete Headwall Stream 5.4% Silt State DC Arch X 20 Concrete Headwall Stream 1.0% Silt State DC Circular Plastic Projecting 3.5% Silt Town DC Circular Plastic Projecting 0.9% Silt Town

28 Barrier Latitude Longitude Shape Length (ft) Dimensions (in) Inlet Type Bottom Slope Stream Bed Ownership DC Box X 26 Concrete Headwall Stream 6.2% Silt State DC Circular Plastic Wingwall 8.0% Silt State DC Circular Metal Headwall 1.6% Silt State DC Circular Metal Wingwall 1.1% Silt Town DC Circular Plastic Projecting 0.5% Rock Town DC Circular Metal Projecting 1.2% Silt Town DC Circular Plastic Projecting 6.1% Gravel Town DC Circular Metal Projecting 11.3% Silt Town DC Circular Plastic Projecting 3.6% Silt Town DC Circular Plastic Projecting 4.2% Rock Town DC Circular Metal Wingwall 12.3% Silt Town DC Circular Plastic Projecting 12.3% Gravel Town DC Box X 32 Concrete Headwall Stream 11.2% Rock Town DC Circular Metal Projecting 8.7% Silt Town DC Box X 38 Concrete Headwall Stream 1.0% Rock Town DC Circular Concrete Wingwall 1.1% Silt State DC Circular Plastic Projecting 3.5% Rock Town DC Circular Plastic Projecting 3.5% Rock Town DC Circular Plastic Wingwall 2.6% Rock Private DC Circular Plastic Projecting 6.5% Silt Town DC Circular Plastic Projecting 3.1% Gravel Town DC Circular Plastic Projecting 3.1% Gravel Town DC Circular Plastic Projecting 1.7% Gravel Town DC Circular Plastic Projecting 1.7% Gravel Town DC Circular Plastic Projecting 8.0% Silt Town DC Circular Plastic Projecting 1.2% Silt Town DC Circular Plastic Projecting 5.0% Gravel Town DC Circular Plastic Projecting 0.5% Rock Town DC Circular Plastic Projecting 3.8% Gravel Town DC Circular Plastic Projecting 3.8% Gravel Town

29 Barrier Latitude Longitude Shape Length (ft) Dimensions (in) Inlet Type Bottom Slope Stream Bed Ownership DC Circular Plastic Projecting 0.8% Gravel Town DC Circular Concrete Headwall 1.8% Silt Town DC Circular Metal Projecting 1.0% Silt Town DC Circular Metal Projecting 1.0% Silt Town DC Circular Plastic Projecting 2.0% Silt Town DC Circular Plastic Projecting 2.0% Silt Town DC Circular Plastic Projecting 1.6% Gravel Town DC Circular Plastic Projecting 16.7% Silt Town DC Circular Metal Wingwall 4.4% Rock Town DC Circular Plastic Projecting 2.4% Silt Town DC Box X 42 Concrete Headwall Stream 27.7% Rock Town DC Box X 45 Concrete Headwall Stream 14.8% Rock Town DC Circular Plastic Projecting 9.6% Gravel Private DC Circular Metal Projecting 1.2% Gravel Private DC Circular Plastic Projecting 1.1% Gravel Private DC Circular Metal Wingwall 0.3% Silt Town DC Circular Plastic Wingwall 5.1% Silt Private DC Circular Metal Wingwall 10.2% Silt Town DC Circular Plastic Projecting 11.4% Silt Town DC Circular Plastic Projecting 9.5% Rock Town DC Circular Plastic Projecting 0.5% Silt Town DC Oval X 40 Metal Mitered 2.3% Rock Town DC Oval X 40 Metal Mitered 2.3% Rock Town DC Circular Plastic Projecting 11.5% Gravel Town DC Circular Plastic Projecting 7.4% Silt Town DC Circular Concrete Headwall 3.3% Silt State DC Circular Plastic Projecting 7.7% Gravel Private DC Box X 40 Concrete Wingwall Stream 3.2% Rock Private DC Box X 36 Concrete Headwall Stream 21.6% Rock County DC Box X 60 Concrete Headwall Stream 3.0% Rock County

30 Barrier Latitude Longitude Shape Length (ft) Dimensions (in) Inlet Type Bottom Slope Stream Bed Ownership DC Circular Metal Projecting 21.4% Silt Town DC Circular Concrete Wingwall 0.5% Silt State DC Circular Plastic Projecting 1.0% Silt Town DC Circular Plastic Projecting 0.8% Silt Town DC Circular Plastic Projecting 7.3% Silt Town DC Circular Plastic Projecting 11.3% Boulder Town DC Oval X 42 Metal Projecting 1.3% Rock Town DC Circular Plastic Projecting 18.0% Gravel Town DC Box X 44 Concrete Wingwall Stream 6.0% Silt County DC Box X 36 Concrete Headwall Stream 1.0% Silt County DC Box X 36 Concrete Wingwall Stream 9.8% Rock County DC Circular Concrete Wingwall 7.3% Silt State DC Circular Metal Projecting 1.3% Rock County DC Circular Plastic Projecting 20.7% Rock Town DC Circular Metal Headwall 3.4% Rock Town DC Oval X 49 Metal Headwall 11.9% Rock Town DC Arch X 52 Metal Headwall Stream 3.8% Rock Town DC Circular Plastic Projecting 0.8% Silt Town DC Circular Plastic Projecting 3.6% Silt Town DC Oval X 42 Metal Projecting 2.1% Rock Town DC Circular Plastic Projecting 2.7% Gravel Town DC Circular Plastic Projecting 4.9% Gravel Town DC Circular Concrete Projecting 8.7% Gravel County DC Circular Plastic Wingwall 10.2% Silt Town DC Circular Plastic Projecting 2.4% Gravel Town DC Circular Plastic Projecting 3.0% Silt Town DC Circular Concrete Projecting 1.4% Silt County DC Circular Metal Projecting 8.3% Rock Private DC Circular Metal Projecting 8.3% Rock Private DC Circular Metal Wingwall 26.8% Rock Private

31 Barrier Latitude Longitude Shape Length (ft) Dimensions (in) Inlet Type Bottom Slope Stream Bed Ownership DC Oval X 50 Concrete Headwall 4.3% Rock Private DC Circular Metal Projecting 9.2% Rock Private DC Circular Plastic Projecting 6.8% Silt Private DC Oval X 32 Metal Projecting 1.0% Silt Town DC Circular Metal Headwall 6.5% Rock State DC Box X 36 Concrete Headwall 4.4% Silt State DC Circular Concrete Wingwall 0.5% Rock State DC Circular Metal Projecting 28.5% Rock Town DC Circular Plastic Projecting 26.0% Gravel Town DC Circular Concrete Headwall 0.5% Silt County DC Oval X 48 Metal Projecting 0.6% Silt County DC Circular Concrete Headwall 2.7% Rock County DC Circular Concrete Headwall 2.7% Rock County DC Circular Concrete Headwall 20.4% Gravel County DC Circular Concrete Headwall 20.4% Gravel County DC Circular Plastic Projecting 14.8% Rock Town DC Circular Plastic Headwall 4.9% Silt Town DC Box X 72 Concrete Wingwall 1.8% Silt State DC Circular Plastic Projecting 4.5% Silt Town DC Circular Metal Projecting 1.0% Rock State DC Circular 32 Unsure Concrete Projecting 24.4% Silt County DC Circular Plastic Projecting 0.9% Rock Town DC Box X 68 Concrete Wingwall Stream 1.6% Rock Town DC Box X 72 Other Wingwall Stream 12.1% Rock Town OC Circular Concrete Headwall 4.0% Silt Town OC Circular Concrete Headwall 3.0% Rock County OC Box 23 24x12 Concrete Headwall Stream 1.0% Silt Town OC Circular Metal Projecting 5.0% Silt Town OC Circular Concrete Headwall 3.0% Rock County OC Circular Metal Projecting 1.0% Rock County

32 Barrier Latitude Longitude Shape Length (ft) Dimensions (in) Inlet Type Bottom Slope Stream Bed Ownership OC Circular Metal Projecting 7.0% Gravel Town OC Box 22 24x26 Concrete Other 5.0% Gravel Town OC Box 24 24x12 Concrete Headwall Stream 2.0% Silt Town OC Box 24 24x17 Concrete Headwall Stream 5.0% Silt Town OC Box 24 24x22 Concrete Headwall Stream 3.0% Silt Town OC Box 24 24x24 Concrete Headwall Stream 3.0% Rock Town OC Circular Metal Headwall 4.0% Gravel Town OC Circular Metal Headwall 3.0% Silt Town OC Circular Metal Projecting 10.0% Rock Town OC Circular Metal Projecting 10.0% Rock Town OC Circular Metal Projecting 10.0% Gravel Town OC Circular Metal Projecting 6.0% Silt Town OC Circular Metal Projecting 4.0% Silt Town OC Circular Metal Projecting 3.0% Silt Town OC Circular Metal Projecting 4.0% Gravel Town OC Circular Metal Headwall 3.0% Rock Town OC Box 28 24x24 Concrete Headwall Stream 2.0% Gravel Town OC Box 30 24x27 Concrete Headwall Stream 3.0% Rock Town OC Box 36 24x20 Plastic Headwall Stream 5.0% Rock Town OC Circular Plastic Headwall 4.0% Rock Town OC Box 30 24x24 Concrete Headwall Stream 3.0% Gravel Town OC Circular Concrete Headwall 3.0% Rock County OC Circular Concrete Projecting 1.0% Rock County OC Circular Metal Headwall 1.0% Silt County OC Circular Concrete Projecting 3.0% Silt County OC Circular Concrete Headwall 2.0% Rock County OC Circular Concrete Headwall 0.0% Silt County OC Circular Metal Wingwall 2.0% Rock County OC Circular Concrete Headwall 7.0% Gravel County OC Circular Concrete Headwall 14.0% Silt County

33 Barrier Latitude Longitude Shape Length (ft) Dimensions (in) Inlet Type Bottom Slope Stream Bed Ownership OC Circular Concrete Headwall 7.0% Gravel County OC Circular Concrete Projecting 3.0% Rock County OC Circular Concrete Projecting 3.0% Rock County OC Circular Concrete Headwall 7.0% Gravel County OC Circular Concrete Headwall 11.0% Gravel County OC Circular Concrete Headwall 2.0% Silt County OC Circular Concrete Headwall 8.0% Gravel County OC Circular Concrete Headwall 12.0% Rock County OC Circular Metal Headwall 8.0% Rock County OC Circular Metal Other 8.0% Gravel County OC Circular 0 48 Concrete Wingwall 0.0% Rock County OC Circular 0 24 Concrete Headwall 0.0% Rock County OC Circular 0 18 Concrete Projecting 0.0% Rock County OC Circular Metal Projecting 1.0% Asphault Town OC Circular Plastic Projecting 2.0% Gravel Town OC Circular Plastic Projecting 3.0% Silt Town OC Circular Plastic Projecting 6.0% Gravel Town OC Circular Plastic Projecting 2.0% Rock Town OC Circular Plastic Projecting 2.0% Rock Town OC Circular Concrete Projecting 4.0% Silt Town OC Circular Metal Headwall 5.0% Asphault Town OC Circular 0 18 Plastic Headwall 0.0% Rock Town OC Circular Concrete Projecting 4.0% Rock Town OC Circular Plastic Projecting 5.0% Rock Town OC Circular Metal Headwall 8.0% Rock Town OC Circular Metal Projecting 2.0% Rock Town OC Circular Plastic Projecting 4.0% Silt Town OC Box 32 24x24 Concrete Headwall Stream 8.0% Rock Town OC Circular Plastic Headwall 2.0% Gravel Town OC Box 35 24x24 Concrete Headwall Stream 8.0% Rock Town

34 Barrier Latitude Longitude Shape Length (ft) Dimensions (in) Inlet Type Bottom Slope Stream Bed Ownership OC Box 0 24x24 Concrete Headwall Stream 0.0% Rock Town OC Circular Plastic Headwall 7.0% Rock Town OC Circular Concrete Projecting 3.0% Rock Town OC Circular Concrete Projecting 3.0% Rock Town OC Circular Concrete Projecting 2.0% Rock Town OC Circular Plastic Mitered 3.0% Silt Town OC Circular Concrete Headwall 1.0% Silt Town OC Circular Concrete Headwall 0.0% Silt Town OC Circular Concrete Headwall 0.0% Silt Town OC Circular Concrete Headwall 0.0% Gravel Town OC Circular Plastic Projecting 10.0% Silt Town OC Circular Plastic Headwall 9.0% Silt Town OC Circular Concrete Projecting 11.0% Gravel Town OC Circular Metal Projecting 3.0% Silt Town OC Circular Metal Wingwall 3.0% Rock County OC Circular Concrete Headwall 4.0% Silt County OC Circular Plastic Headwall 2.0% Rock County OC Circular Plastic Projecting 4.0% Gravel Town OC Circular Plastic Projecting 7.0% Rock State OC Circular Concrete Headwall 4.0% Rock State OC Circular Concrete Projecting 3.0% Rock State OC Circular Metal Projecting 4.0% Gravel State OC Circular 0 15 Concrete Headwall 0.0% Gravel State OC Circular Plastic Headwall 1.0% Rock State OC Circular Concrete Headwall 3.0% Silt State OC Circular Concrete Headwall 4.0% Silt State OC Circular Concrete Headwall 2.0% Gravel State OC Circular Concrete Headwall 5.0% Rock State OC Circular Concrete Projecting 6.0% Rock State OC Circular Concrete Projecting 9.0% Rock State

35 NYSDEC Field Sheet Date: Recent Weather Patterns: General Information Barrier : Barrier Type: Barrier Ownership: Watershed Name: Stream Name: Road Name: Road Type: Accessibility: Comments: Characteristics Name / : : Shape: Diameter (cm): Length (m): Outlet Perch (cm): Inlet Drop (cm): Plunge Pool: Plunge Pool Depth (cm): Plunge Pool Width (cm): Dry Pathway Inside of Structure: Dry Pathway Width (cm): Condition: Is Passable for Animals: Is Clogged: Picture Numbers: Notes: Stream Characteristics Category Upstream Downstream Riparian Area Width

36 Riparian Area Condition Stream Bed Stream Width Stream Depth Surrounding Land Use Miscellaneous Evidence of Unique Vegetation: Unique Vegetation: Evidence of Wildlife: Wildlife: Evidence of Recreational Use: RU: Comments / Notes: Legend Accessibility - 1 = inaccessible 2 = difficult to access 3 = moderately difficult to access 4 = easy to access 5 = no access issues Condition 1 = Collapsed / nonexistent 2 = severely impaired 3 = moderately impaired 4 = slightly impaired 5 = excellent Is Passable 1 = No completely impassable 2 = some animals could pass 3 = Yes easy for animals to pass Riparian Area Condition 1 = worst (eroded, little or no vegetation, lack of plant biodiversity, no canopy cover, etc.) 2 = poor 3 = average 4 = good 5 = Excellent (no erosion, large variety of plant species, adequate canopy cover, etc.)

37 References DeGaetano, A.T., Time-dependent changes in extreme-precipitation return-period amounts in the continental United States. Journal of Applied Meteorology and Climatology 48(10): Fry, J., Xian, G., Jin, S., Dewitz, J., Homer, C., Yang, L., Barnes, C., Herold, N., and Wickham, J., Completion of the 2006 National Land Cover Database for the Conterminous United States. PE&RS, Vol. 77(9): Gesch, D.B., 2007 The National Elevation Dataset, in Maune, D., ed., Digital Elevation Model Technologies and Applications: The DEM Users Manual, 2nd Edition: Bethesda, Maryland, American Society for Photogrammetry and Remote Sensing, p Gesch, D., Oimoen, M., Greenlee, S., Nelson, C., Steuck, M., and Tyler, D., The National Elevation Dataset: Photogrammetric Engineering and Remote Sensing, v. 68, no. 1, p Kirpich, Z.P., Time of concentration of small agricultural watersheds. Civil engineering (Johannesburg, South Africa), 10(6): 362. Meixler, M.S., M.B. Bain, M.T. Walter., Predicting barrier passage and habitat suitability for migratory fish species. Ecological Modeling 220: USDA-NRCS, Urban Hydrology for Small Watersheds, Technical Release-55 (TR-55). USDA-NRCS, U.S. General Soil Map (STATSGO2). Available online at Accessed 03/09/2010.

Andrew Meyer, New York State Department of Environmental Conservation Hudson River Estuary

Andrew Meyer, New York State Department of Environmental Conservation Hudson River Estuary Determining Peak Flow Under Different Scenarios and Assessing Organism Passage Potential: Identifying and Prioritizing Undersized and Poorly Passable Culverts: year 2 Dr. Todd Walter, Biological and Environmental