027002 Wharfe at Flint Mill Weir 1970
Measuring authority: EA Grid reference: 44 (SE) 422 473 Catchment area (sq km): 758.9
First year: 1936 Level stn. (m OD): 13.70 Max alt. (m OD): 704
Daily mean gauged discharges (cubic metres per second)
DAY JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1 9.426 14.650 12.340 23.320 13.530 3.458 7.383 6.591 5.345 9.370 118.600 26.010
2 9.273 14.850 14.170 15.230 10.890 3.665 12.640 6.209 8.218 29.100 89.880 23.400
3 8.597 76.320 12.100 13.550 10.500 3.396 10.310 5.374 20.670 17.930 90.720 59.170
4 7.813 45.030 10.930 17.930 10.040 3.221 6.455 4.771 9.421 10.630 44.510 33.250
5 7.332 26.300 9.975 15.770 9.248 2.671 5.108 4.264 8.557 25.460 45.160 25.390
6 7.643 19.520 9.143 30.340 8.639 2.524 4.539 4.038 6.956 23.440 31.200 44.440
7 5.736 15.450 8.221 20.210 8.509 2.026 4.448 3.990 6.509 20.640 20.840 36.060
8 7.850 15.590 7.895 15.960 8.286 2.032 5.051 3.681 6.353 21.840 20.190 23.190
9 8.761 16.490 8.362 13.520 7.304 2.639 12.060 3.497 6.548 12.360 26.150 17.080
10 33.940 19.580 8.122 13.340 6.854 2.655 8.198 4.095 46.340 8.877 17.180 14.920
11 45.910 16.690 8.852 11.670 7.491 2.739 5.727 5.360 69.070 7.527 43.250 13.450
12 38.860 13.510 11.120 67.440 7.148 4.802 5.000 4.641 37.130 7.360 38.190 11.620
13 32.810 12.000 9.842 104.600 6.970 3.717 8.928 4.318 18.010 6.953 34.210 11.110
14 31.530 10.940 8.390 40.410 6.636 2.628 13.210 3.857 19.410 6.458 29.250 10.840
15 30.670 9.282 7.824 48.220 6.472 2.537 9.191 3.565 12.720 6.217 19.060 9.987
16 26.960 8.526 8.583 74.940 5.985 2.737 6.704 14.520 9.624 5.798 17.440 9.491
17 20.620 8.741 13.380 52.950 5.235 2.564 5.430 13.360 16.840 5.227 45.620 10.710
18 43.930 8.781 16.900 31.720 5.402 2.457 4.743 7.898 12.450 4.938 82.300 11.130
19 36.080 8.993 15.740 21.470 5.725 2.286 4.822 6.259 9.930 5.317 62.960 9.135
20 42.720 35.590 15.020 17.010 5.611 2.246 4.612 6.568 9.075 5.609 38.580 9.259
21 52.380 71.810 15.170 18.750 5.546 1.908 4.428 20.070 10.840 5.215 37.640 9.879
22 91.720 121.200 19.310 68.700 5.470 1.854 4.061 27.960 8.379 4.802 26.230 8.574
23 54.530 139.200 14.230 117.000 5.212 1.972 10.560 11.830 7.411 4.737 54.360 8.164
24 41.260 58.920 13.000 39.680 4.697 2.079 39.730 8.334 6.704 5.252 49.570 8.390
25 52.360 34.480 10.460 43.250 4.587 1.908 28.220 6.913 6.203 78.670 25.300 7.898
26 32.000 23.810 9.423 37.460 4.581 2.184 15.060 6.330 5.266 31.800 21.360 8.467
27 24.230 19.170 8.264 23.200 4.443 2.262 14.950 5.846 4.811 19.720 19.030 8.690
28 18.920 16.080 7.949 17.640 4.544 9.759 34.050 5.456 5.184 48.060 22.670 9.016
29 19.320 7.788 25.400 4.587 7.995 14.480 4.836 5.207 46.490 39.840 11.370
30 19.670 27.050 16.560 4.632 11.280 9.384 4.267 8.447 90.390 35.540 11.780
31 14.650 50.820 4.386 7.694 4.321 68.630 9.738
Average 28.310 31.480 12.920 35.240 6.747 3.340 10.550 7.194 13.590 20.800 41.560 16.500
Lowest 5.736 8.526 7.788 11.670 4.386 1.854 4.061 3.497 4.811 4.737 17.180 7.898
Highest 91.720 139.200 50.820 117.000 13.530 11.280 39.730 27.960 69.070 90.390 118.600 59.170
Monthly total
(million cu m) 75.82 76.16 34.59 91.35 18.07 8.66 28.27 19.27 35.22 55.71 107.70 44.20
Runoff (mm) 100 100 46 120 24 11 37 25 46 73 142 58
Rainfall (mm) 129 111 73 147 13 47 121 75 88 120 182 61
Statistics of monthly data for previous record (Oct 1955 to Dec 1969)
Mean Avg. 25.670 22.710 19.540 16.060 12.820 7.352 9.373 13.890 15.170 17.620 22.270 27.770
flows: Low 4.472 2.974 6.741 5.197 3.911 1.545 3.601 1.795 1.419 6.209 6.876 10.230
(year) 1963 1963 1961 1957 1960 1957 1959 1959 1959 1969 1958 1963
High 39.260 54.590 36.400 29.330 26.750 14.540 16.440 41.340 33.520 54.000 51.090 62.090
(year) 1961 1966 1963 1966 1967 1969 1963 1956 1968 1967 1963 1965
Runoff: Avg. 91 73 69 55 45 25 33 49 52 62 76 98
Low 16 9 24 18 14 5 13 6 5 22 23 36
High 139 174 128 100 94 50 58 146 115 191 174 219
Rainfall: Avg. 101 83 77 76 82 76 93 110 106 103 104 122
Low 41 20 28 10 25 33 35 18 8 38 33 41
High 165 194 148 130 181 140 185 226 241 225 211 224
Summary statistics Factors affecting runoff
1970
For 1970 For record As % of $ Reservoir(s) in catchment.
preceding 1970 pre-1970 $ Abstraction for public water supplies.
Mean flow 18.870 17.510 108 $ Flow reduced by industrial and/or
Lowest yearly mean 12.390 1964 agricultural abstractions.
Highest yearly mean 23.300 1966 $ Augmentation from surface water and/or
Lowest monthly mean 3.340 Jun 1.419 Sep 1959 groundwater.
Highest monthly mean 41.560 Nov 62.090 Dec 1965
Lowest daily mean 1.854 22 Jun 0.425 23 Jun 1957
Highest daily mean 139.200 23 Feb 233.600 4 Dec 1960
10% exceedance 44.610 40.410 110
50% exceedance 10.410 9.766 107
95% exceedance 2.681 2.489 108
Annual total (million cu m) 595.10 552.60 108
Annual runoff (mm) 784 728 108
Annual rainfall (mm) 1167 1133 103
{1961-90 rainfall average (mm) 1161}
Station and catchment description
Broad-crested masonry weir 47m wide; c/m cableway originally 1.5km u/s then moved to new ultrasonic station at Tadcaster
in 1990. Insensitive at low flows. Does not drown at high flows, though small amount of bypassing on the right bank.
Level data: 1936-1955. Recalibration (from 1965) completed but flows reprocessed from 1982 only. Pre-1965 data less
reliable. Mill race opened in early 1990s (not rated) so flows not reliable. Regulation effect of headwater reservoirs
evident at low flows. Small net export of water (inc. Bradford supply).
Mixed geology of moderate permeability - mainly Carboniferous Limestone, grits and Coal Measures with over 40%
superficial deposits. Predominantly mixed rural catchment, 60% grassland, with moorland headwaters.
In line with Natural Environment Research Council policy, the provision of data from the National River Flow Archive confers only a right to use the data. Ownership of the data, or the associated Intellectual Property Rights, will not normally be transferred. Data received from the NRFA must not be sold, or passed on to any third party. Reproduction is authorised, except for commercial purposes, provided the sources is acknowledged.
Through the use of quality control procedures every effort is made to maintain and improve the quality of data. However, NERC, the Environment Agency, the Scottish Environment Protection Agency and the Rivers Agency accepts no liability for any loss or damage, cost or claims arising directly or indirectly their use.