Water-Data Report 2012 01350100 SCHOHARIE NEAR GRAND GORGE, NY Upper Hudson Basin Schoharie Subbasin

LOCATION.--Lat 42°21′21″, long 74°26′42″ referenced to North American Datum of 1927, Schoharie County, NY, Hydrologic Unit 02020005, in intake house on Intake Road, 1.6 mi north of junction of Intake Road and State Highway 23, 2.5 mi upstream from Gilboa Dam, and 2.6 mi east of Grand Gorge. DRAINAGE AREA.--315 mi².

SURFACE-WATER RECORDS PERIOD OF RECORD.--January 1973 to current year. Monthly contents only published as "at Gilboa" for September 1928 to December1972. REVISED RECORDS.--WDR NY-86-1: 1956 (maximum elevation). WDR NY-90-1: Drainage area. GAGE.--Water-stage recorder. Supplementary nonrecording gage used for periods when reservoir elevation is below 1,065.00 ft. Prior to Nov. 2001, supplementary nonrecording gage used for periods when reservoir elevation was below 1,072.50 ft. Datum of gage is NGVD of 1929 (levels by Board of Water Supply, City of ). COOPERATION.--Capacity table and once-daily nonrecording gage readings provided by Department of Environmental Protection, City of New York. REMARKS.--Reservoir is formed by masonry and earth dam. Storage began July 24, 1926. Usable capacity 19,583 mil gal between minimum operating level, elevation 1,050.00 ft, and crest of spillway, elevation 1,130.00 ft. Dead storage below elevation 1,050.00 ft, 1,968 mil gal. A 220 ft-wide notch was cut into the 1,324 ft-wide spillway in February 2006, elevation of the crest of the notch 1,124.5 ft, and four 4 ft-diameter siphons were installed on the dam in March 2006. The construction of the notch and siphons are part of a dam and spillway reconstruction and modification project. Additional information on modifications that have taken place since 2006 and a project description and schedule can be accessed at http://www.nyc.gov/html/dep/html/environmental_reviews/gilboa.shtml. Figures given herein represent usable contents. Reservoir impounds water except for periods of spilling, for diversion through Shandaken Tunnel into to , for water supply. Satellite gage-height telemeter at station. EXTREMES FOR PERIOD OF RECORD.--Maximum elevation, 1,137.73 ft, Aug. 28, 2011, contents, 22,679 mil gal; minimum elevation observed (after initial filling), 1,062.00 ft, Aug. 20, 1970, contents, 1,520 mil gal. EXTREMES FOR CURRENT YEAR.--Maximum elevation, 1,128.33 ft, Dec. 8, contents, 18,983 mil gal; minimum elevation, 1,091.19 ft, Sept. 18, contents, 7,719 mil gal.

Capacity table (elevation, in feet, and usable contents in million gallons) 1,063.0 1,670 1,120.0 16,100 1,080.0 4,970 1,133.0 20,700

U.S. Department of the Interior Suggested citation: U.S. Geological Survey, 2013, Water-resources data for the United States, Water U.S. Geological Survey Year 2012: U.S. Geological Survey Water-Data Report WDR-US-2012, site 01350100, accessed at http://wdr.water.usgs.gov/wy2012/pdfs/01350100.2012.pdf Water-Data Report 2012 01350100 SCHOHARIE RESERVOIR NEAR GRAND GORGE, NY—Continued

LAKE OR RESERVOIR WATER SURFACE ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2011 TO SEPTEMBER 2012 DAILY MEAN VALUES Day Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

1 1,126.66 1,126.16 1,126.83 1,125.44 1,120.59 1,114.76 1,123.44 1,126.12 1,125.82 1,121.66 1,112.41 1,102.38 2 1,126.49 1,126.28 1,126.47 1,125.38 1,120.82 1,114.67 1,123.81 1,126.02 1,125.51 1,121.28 1,112.17 1,100.70 3 1,126.39 1,126.36 1,126.27 1,125.19 1,120.79 1,114.62 1,124.09 1,125.95 1,125.50 1,120.90 1,111.91 1,099.05 4 1,125.98 1,126.40 1,126.16 1,124.61 1,120.53 1,114.88 1,124.20 1,125.97 1,125.77 1,120.52 1,111.63 1,098.29 5 1,125.77 1,126.34 1,126.13 1,124.14 1,120.16 1,115.04 1,123.77 1,125.63 1,125.86 1,120.12 1,111.35 1,097.98 6 1,125.56 1,126.27 1,126.15 1,123.74 1,119.68 1,114.98 1,123.22 1,124.89 1,125.83 1,119.72 1,111.05 1,097.66 7 1,125.37 1,126.20 1,126.46 1,123.28 1,119.17 1,114.99 1,122.63 1,124.13 1,125.86 1,119.30 1,110.73 1,097.36 8 1,125.19 1,126.14 1,128.01 1,122.76 1,118.55 1,115.36 1,122.02 1,124.07 1,125.82 1,118.88 1,110.42 1,097.05 9 1,124.98 1,126.07 1,127.20 1,122.18 1,117.94 1,117.15 1,121.41 1,125.09 1,125.80 1,118.47 1,110.11 1,096.77 10 1,124.69 1,126.00 1,126.83 1,122.54 1,117.71 1,118.76 1,120.77 1,125.84 1,125.70 1,118.14 1,109.81 1,096.50 11 1,124.31 1,126.13 1,126.57 1,123.07 1,117.61 1,119.78 1,120.10 1,125.60 1,125.49 1,117.86 1,109.52 1,096.18 12 1,123.86 1,126.16 1,126.39 1,123.50 1,117.36 1,120.62 1,119.42 1,124.88 1,125.38 1,117.57 1,109.26 1,095.84 13 1,123.46 1,126.12 1,126.26 1,123.15 1,117.08 1,121.20 1,118.82 1,124.23 1,125.40 1,117.27 1,109.02 1,095.49 14 1,124.42 1,126.07 1,126.19 1,122.73 1,116.79 1,121.61 1,118.72 1,124.41 1,125.66 1,116.98 1,108.75 1,095.08 15 1,126.76 1,126.00 1,126.24 1,121.90 1,116.51 1,122.06 1,118.69 1,125.39 1,125.70 1,116.72 1,108.51 1,093.77 16 1,126.18 1,125.96 1,126.42 1,120.79 1,116.19 1,122.42 1,118.66 1,126.18 1,125.48 1,116.51 1,108.26 1,092.17 17 1,125.97 1,126.08 1,126.32 1,119.94 1,115.98 1,122.79 1,118.58 1,125.82 1,125.32 1,116.22 1,108.02 1,091.57 18 1,126.14 1,126.12 1,126.15 1,119.58 1,115.98 1,123.10 1,118.41 1,125.52 1,125.16 1,115.92 1,107.76 1,091.87 19 1,126.07 1,126.04 1,126.00 1,118.90 1,115.95 1,123.33 1,117.77 1,125.46 1,125.00 1,115.61 1,107.46 1,102.37 20 1,126.42 1,125.97 1,126.02 1,118.10 1,115.86 1,123.63 1,117.15 1,125.65 1,124.82 1,115.31 1,107.16 1,105.74 21 1,126.60 1,125.92 1,126.01 1,117.15 1,115.71 1,123.85 1,116.18 1,125.61 1,124.62 1,115.04 1,106.90 1,107.10 22 1,126.34 1,125.87 1,126.15 1,116.11 1,115.61 1,123.91 1,115.62 1,125.75 1,124.38 1,114.75 1,106.60 1,107.99 23 1,126.19 1,126.96 1,126.35 1,115.23 1,115.51 1,123.64 1,121.26 1,126.22 1,124.12 1,114.50 1,106.30 1,108.73 24 1,126.09 1,127.04 1,126.44 1,115.06 1,115.43 1,123.23 1,126.43 1,126.15 1,123.84 1,114.25 1,105.96 1,109.41 25 1,126.04 1,126.61 1,126.23 1,115.18 1,115.41 1,122.70 1,126.24 1,126.16 1,123.56 1,113.96 1,105.60 1,109.91 26 1,125.98 1,126.39 1,126.16 1,114.85 1,115.24 1,122.19 1,126.03 1,126.16 1,123.28 1,113.68 1,105.27 1,110.33 27 1,126.00 1,126.24 1,126.08 1,115.59 1,115.06 1,121.91 1,126.05 1,126.09 1,122.99 1,113.41 1,104.91 1,110.68 28 1,126.16 1,126.22 1,126.84 1,118.49 1,114.96 1,122.15 1,126.30 1,126.03 1,122.67 1,113.13 1,104.62 1,111.09 29 1,126.13 1,126.18 1,126.45 1,119.70 1,114.84 1,122.55 1,126.27 1,125.94 1,122.35 1,112.98 1,104.36 1,112.15 30 1,126.13 1,127.10 1,126.08 1,120.25 --- 1,122.88 1,126.19 1,125.93 1,122.01 1,112.84 1,104.09 1,113.03 31 1,126.13 --- 1,125.66 1,120.42 --- 1,123.16 --- 1,125.91 --- 1,112.64 1,103.71 --- Mean 1,125.76 1,126.25 1,126.37 1,120.61 1,117.21 1,120.26 1,121.74 1,125.57 1,124.82 1,116.65 1,108.18 1,101.47 Max 1,126.76 1,127.10 1,128.01 1,125.44 1,120.82 1,123.91 1,126.43 1,126.22 1,125.86 1,121.66 1,112.41 1,113.03 Min 1,123.46 1,125.87 1,125.66 1,114.85 1,114.84 1,114.62 1,115.62 1,124.07 1,122.01 1,112.64 1,103.71 1,091.57

† 18,196 18,545 17,973 16,273 14,430 17,212 18,193 18,103 16,718 13,739 10,986 13,996 †† -16.7 +18.0 -28.6 -84.8 -98.3 +139 +50.6 -4.49 -71.4 -149 -137 +155

Calendar Year 2011 Water Year 2012 Mean 1,121.44 1,119.60 Max 1,130.56 1,128.01 Min 1,103.99 1,091.57 †† +13.3 -19.2

† Contents, in million gallons, at 2400 hours on last day of month. †† Change in contents, equivalent in cubic feet per second.

— 2 — Water-Data Report 2012 01350100 SCHOHARIE RESERVOIR NEAR GRAND GORGE, NY—Continued

1,130

1,125

1,120

1,115

1,110

1,105 ABOVE NGVD 1929, FEET

1,100 MEAN LAKE OR RESERVOIR WATER SURFACE ELEVATION SURFACE WATER RESERVOIR OR LAKE MEAN 1,095

1,090 O N D J F M A M J J A S 2011 2012

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