CONNECTICUT RIVER BASIN 01186500 STILL RIVER AT ROBERTSVILLE, CT LOCATION.--Lat 4158'04", long 7302'04", Litchfield County, Hydrologic Unit 01080207, on left bank 1,500 ft downstream from Sandy Brook, 1 mi southeast of Robertsville, 1 mi northwest of Riverton, and 1 mi upstream from mouth. DRAINAGE AREA.--85.0 mi2. PERIOD OF RECORD.--July 1948 to September 1967, July 1969 to current year. REVISED RECORDS.--WSP 1901: 1948-60. WDR-CT-83-1: Drainage area. GAGE.--Water-stage recorder. Datum of gage is 510.24 ft above sea level. REMARKS.--Records good except for periods of estimated record, which are poor. Flow regulated by power plant, Mad River and Sucker Brook Detention Reservoirs, and Highland Lake. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 214 197 334 e220 150 168 557 203 81 16 8.7 46 2 190 188 1510 e230 141 203 420 210 82 12 8.2 36 3 175 179 979 e240 135 212 389 373 80 57 15 28 4 162 172 663 260 131 174 532 588 76 64 28 25 5 156 168 460 266 278 169 698 374 71 41 42 19 6 148 165 380 276 307 346 730 342 59 30 30 15 7 141 172 366 233 214 251 747 365 55 24 23 14 8 159 328 364 e175 166 e180 557 278 54 21 17 15 9 600 1590 331 e160 e135 e150 377 254 48 45 15 13 10 507 955 299 e180 e120 e145 291 334 46 116 15 12 11 389 614 284 e160 e112 e150 254 274 34 91 12 24 12 285 370 378 e148 e109 e135 266 218 28 50 11 123 13 238 302 541 e140 e106 e129 524 189 32 36 25 72 14 206 264 509 e130 e102 e127 390 186 36 28 37 45 15 184 241 518 e126 e101 253 290 168 32 22 30 32 16 170 226 464 257 e100 e170 251 154 28 54 23 24 17 160 218 565 242 e97 e140 235 148 26 38 18 22 18 153 214 764 e218 e95 e129 317 142 29 20 36 24 19 199 225 762 e200 158 130 390 183 53 23 32 23 20 1900 228 650 e190 260 133 388 314 42 21 24 25 21 1300 211 e400 e180 222 130 364 232 35 16 63 27 22 813 196 348 e172 455 156 308 182 31 40 76 25 23 609 182 313 e169 354 153 263 156 30 30 57 22 24 485 169 363 e166 231 129 231 139 35 23 40 21 25 325 165 770 382 e150 115 213 132 26 20 29 20 26 282 362 460 e230 e140 535 190 138 48 18 24 20 27 255 384 358 e198 184 398 175 121 59 15 28 19 28 256 e240 310 280 215 307 317 107 34 14 46 18 29 262 e200 302 e280 --- 289 342 101 31 13 75 52 30 239 e190 341 e190 --- 343 253 87 23 10 68 47 31 220 --- 290 e152 --- 568 --- 83 --- 9.4 47 --- TOTAL 11382 9315 15376 6450 4968 6617 11259 6775 1344 1017.4 1002.9 908 MEAN 367 311 496 208 177 213 375 219 44.8 32.8 32.4 30.3 MAX 1900 1590 1510 382 455 568 747 588 82 116 76 123 MIN 141 165 284 126 95 115 175 83 23 9.4 8.2 12 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1949 - 1997, BY WATER YEAR (WY) MEAN 127 170 193 190 200 301 378 203 120 57.9 84.1 74.6 MAX 832 569 527 474 621 699 786 577 492 276 1228 363 (WY) 1956 1956 1974 1949 1981 1953 1987 1989 1972 1972 1955 1975 MIN 16.8 24.6 37.5 15.7 47.9 106 92.9 59.4 28.9 12.1 9.32 10.3 (WY) 1958 1965 1981 1981 1980 1989 1985 1965 1995 1957 1957 1995 e Estimated. SUMMARY STATISTICS FOR 1996 CALENDAR YEAR FOR 1997 WATER YEAR WATER YEARS 1949 - 1997 ANNUAL TOTAL 98266 76414.3 ANNUAL MEAN 268 209 174 HIGHEST ANNUAL MEAN 269 1955 LOWEST ANNUAL MEAN 62.0 1965 HIGHEST DAILY MEAN 2100 Jan 28 1900 Oct 20 24800 Aug 19 1955 LOWEST DAILY MEAN 18 Jun 29 8.2 Aug 2 .30 Sep 14 1957 ANNUAL SEVEN-DAY MINIMUM 24 Jun 26 11 Jul 27 2.1 Sep 10 1995 INSTANTANEOUS PEAK FLOW 2430 Oct 20 a44000 Aug 19 1955 INSTANTANEOUS PEAK STAGE 6.30 Oct 20 b16.48 Aug 19 1955 INSTANTANEOUS LOW FLOW 7.6 Aug 3 .20 Sep 14 1957 10 PERCENT EXCEEDS 603 408 377 50 PERCENT EXCEEDS 191 166 101 90 PERCENT EXCEEDS 39 23 23 a From rating curve extended above 5,600 ft3/s on basis of slope-area measurement of peak flow. b From floodmarks.