CONNECTICUT RIVER BASIN
01130000 UPPER AMMONOOSUC RIVER NEAR GROVETON, NH
LOCATION.--Lat 44°37'30", long 71°28'10", Coos County, Hydrologic Unit 01080101, on left bank, 75 ft upstream from
highway bridge, 0.2 mi downstream from Nash Stream, and 2.8 mi northeast of Groveton.
DRAINAGE AREA.--232 mi².
PERIOD OF RECORD.--Discharge records: August 1940 to November 1980, October 1982 to current year.
Water-quality records: Water year 1955.
GAGE.--Water-stage recorder. Elevation of gage is 920 ft above sea level, from topographic map.
REMARKS.--Records good except those for estimated daily discharges which are poor and daily flow below 100 ft³/s during
shifting control period, October 3-8, which are fair. Prior to May 21, 1969, some regulation by pond 9 mi upstream
on Nash Stream. Small diversion upstream for municipal supply of Berlin.
EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 2,900 ft³/s and maximum (*):
Discharge Gage height Discharge Gage height
Date Time (ft³/s) (ft) Date Time (ft³/s) (ft)
Dec. 2 1415 * 3,530 6.02 May 2 0430 3,020 5.66
Feb. 23 1000 Ice Jam * 7.17
Minimum discharge, 56 ft³/s, October 8.
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
1 153 520 e300 e300 e190 e500 1070 2010 703 228 104 284
2 114 429 2200 e310 e185 e680 691 2930 685 218 98 266
3 96 380 2620 e380 e180 e880 551 2370 560 312 107 229
4 89 346 1260 e360 e180 e700 507 1740 480 723 107 221
5 77 334 716 e340 e175 e520 612 1390 430 526 97 201
6 64 333 561 e510 e180 e450 1160 1330 383 340 94 180
7 62 332 480 e440 e175 e390 2110 1710 347 270 87 165
8 60 327 365 e330 e165 e310 2320 1390 318 260 79 163
9 244 387 433 e300 e160 e280 1470 1180 290 467 76 164
10 382 645 412 e310 e160 e250 913 1080 263 792 85 141
11 421 529 373 e300 e155 294 690 1040 243 461 96 132
12 292 427 331 e280 e160 e270 614 954 255 312 123 141
13 234 365 306 e260 e150 e230 569 1120 423 258 232 150
14 191 312 292 e255 e145 e200 568 1280 748 316 664 162
15 156 e250 287 e250 e145 e210 540 1310 464 622 285 148
16 135 e340 278 e245 e140 e180 603 1660 327 684 198 122
17 134 407 288 e255 e140 e160 900 e1500 277 432 215 108
18 142 359 506 e245 e140 e150 1600 e1250 291 315 209 104
19 126 287 630 e230 e180 e150 2560 e1200 986 271 151 102
20 117 278 542 e220 e280 e165 2470 1100 733 259 116 108
21 399 266 e380 e210 e270 198 1980 1060 441 240 119 155
22 2120 251 e310 e205 e600 e160 1670 1020 1290 223 228 152
23 2130 238 e310 e210 e950 e155 1620 1130 1580 205 255 125
24 1040 199 e450 e230 e750 e150 1600 963 815 192 236 132
25 693 e190 1470 e210 e510 e145 1350 858 565 178 204 129
26 538 e175 926 e220 e410 280 1380 843 739 165 162 112
27 427 e190 610 e210 e450 570 1580 717 537 159 139 103
28 399 e170 520 e200 e590 455 1840 622 387 165 700 97
29 410 e160 534 e200 --- 558 1740 621 296 160 579 103
30 391 e170 650 e190 --- 1340 1450 633 253 137 594 218
31 553 --- 411 e185 --- 1520 --- 698 --- 115 371 ---
TOTAL 12389 9596 19751 8390 7915 12500 38728 38709 16109 10005 6810 4617
MEAN 400 320 637 271 283 403 1291 1249 537 323 220 154
MAX 2130 645 2620 510 950 1520 2560 2930 1580 792 700 284
MIN 60 160 278 185 140 145 507 621 243 115 76 97
CFSM 1.72 1.38 2.75 1.17 1.22 1.74 5.56 5.38 2.31 1.39 .95 .66
IN. 1.99 1.54 3.17 1.35 1.27 2.00 6.21 6.21 2.58 1.60 1.09 .74
(|) 6.19 5.16 4.99 4.58 4.69 4.52 3.98 3.07 2.80 2.96 2.79 3.09
STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1940 - 1997, BY WATER YEAR (WY)
MEAN 316 452 350 251 213 448 1420 1146 447 239 204 199
MAX 1057 1128 994 748 851 1374 2416 2695 1115 840 572 1427
(WY) 1991 1970 1974 1978 1970 1945 1954 1972 1947 1996 1969 1954
MIN 69.7 118 68.6 53.3 56.6 74.4 532 402 179 94.0 78.4 51.0
(WY) 1949 1948 1948 1948 1980 1941 1995 1941 1953 1991 1975 1948
SUMMARY STATISTICS FOR 1996 CALENDAR YEAR FOR 1997 WATER YEAR WATER YEARS 1940 - 1997
ANNUAL TOTAL 232355 185519
ANNUAL MEAN 635 508 474
HIGHEST ANNUAL MEAN 696 1954
LOWEST ANNUAL MEAN 297 1980
HIGHEST DAILY MEAN 7340 Apr 24 2930 May 2 8350 Apr 23 1954
LOWEST DAILY MEAN 40 Sep 24 60 Oct 8 32 Sep 14 1948
ANNUAL SEVEN-DAY MINIMUM 61 Sep 19 80 Oct 2 37 Sep 9 1948
INSTANTANEOUS PEAK FLOW 3530 Dec 2 a 24100 May 20 1969
INSTANTANEOUS PEAK STAGE b 7.17 Feb 23 c 12.01 May 20 1969
INSTANTANEOUS LOW FLOW 56 Oct 8 32 Sep 14 1948
ANNUAL RUNOFF (CFSM) 2.74 2.19 2.04
ANNUAL RUNOFF (INCHES) 37.26 29.75 27.75
10 PERCENT EXCEEDS 1480 1280 1110
50 PERCENT EXCEEDS 376 310 243
90 PERCENT EXCEEDS 115 132 94
(|) Diversion in cubic feet per second for municipal supply of Berlin; records furnished by City of Berlin.
a From rating curve extended above 5,600 ft³/s on basis of contracted-opening measurement of peak flow.
b Ice jam.
c From floodmarks. Caused by failure of dam on Nash Stream.
e Estimated.
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