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WATER CONVERSION TABLES

WATER MEASUREMENT TABLE

Table of discharges, Slope of sides 1 to 4 for the trapezoidal weir without end contractions.

Discharges given are 50ths of a cubic foot per second (or Miner's inches).

WIDTH OF CREST OF WEIR

Width in inches 4 6 9 12 15 18 24 30 36 42 48
DEPTH
in inches
1.0 1 2 3 4 5 6 8 10 12 14 16
1.5 2 4 5 7 9 11 15 18 22 26 30
2.0 4 6 8 11 14 17 23 28 34 40 46
2.5 5 8 12 16 20 24 32 40 48 56 64
3.0 7 11 16 21 27 32 42 53 64 75 84
3.5 9 13 20 26 33 40 53 66 79 92 106
4.0 11 16 24 32 40 48 64 80 96 112 128
4.5 13 19 29 38 48 58 77 96 115 134 154
5.0 15 22 34 45 56 67 90 112 134 156 180
5.5 17 26 39 52 64 77 103 129 155 181 206
6.0 20 29 44 58 73 88 118 147 176 205 236
6.6 22 33 50 66 88 100 133 166 199 232 266
7.0 25 37 56 74 93 112 149 186 223 260 298
7.5 27 41 62 82 103 124 165 206 247 288 330
8.0 30 45 68 91 113 136 182 227 272 317 364
8.5 33 50 74 99 124 149 198 248 298 348 396
9.0 36 54 81 108 135 162 216 270 314 368 432
9.5 39 59 88 117 147 176 234 293 352 411 468
10.0 42 63 95 127 158 190 254 317 380 443 508
10.5 46 68 102 136 170 205 273 341 409 477 546
11.0 49 73 110 140 183 220 293 366 439 512 586
11.5 52 78 117 156 195 235 313 391 469 547 622
12.0 56 83 125 165 208 250 333 416 499 582 666
Example: If you have 40 acres of ground and are entitled to 1/2 inch of water per acre, that would = 20 inches of water.  If your weir is 15 inches in width,  then read across the top to the # 15 down that column  to the # 20, then over to the left hand column opposite to # 20, there you will find the number of inches in depth that the water that should be running over your weir in this example is 2.5 in depth.  Handy (Measurement  Formulas ) 1 Miners inch = 9 gallons per minute.  50 Miners inch's =  450 gallons per minute or 1 Cubic  feet per second. (C.F.S.) 1 - C.F.S.  for 24 hrs= 1.9835  Acre feet.  (note) Black Canyon Irrigation District will not deliver less than 5 Miners inch flow.