043005 Avon at Amesbury 1996
Measuring authority: EA Grid reference: 41 (SU) 151 413 Catchment area (sq km): 323.7
First year: 1965 Level stn. (m OD): 67.10 Max alt. (m OD): 294
Daily mean gauged discharges (cubic metres per second)
DAY JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1 4.690 5.104 5.500 5.105 4.013 2.634 1.859 1.321 1.156 1.070 1.128 1.915
2 4.545 5.049 5.492 4.921 3.875 2.607 1.860 1.327 1.125 1.039 1.124 1.848
3 4.349 4.930 5.491 4.849 3.752 2.525 1.890 1.306 1.124 1.031 1.246 2.074
4 4.297 4.894 5.458 4.777 3.696 2.486 1.772 1.282 1.117 1.035 1.656 2.224
5 4.301 4.905 5.349 4.708 3.614 2.446 1.966 1.255 1.100 1.026 1.698 2.010
6 4.487 4.939 5.293 4.689 3.552 2.422 1.867 1.251 1.087 1.033 1.542 1.852
7 5.174 4.844 5.252 4.656 3.501 2.678 1.874 1.234 1.077 1.023 1.526 1.800
8 5.448 4.753 5.341 4.534 3.473 2.774 1.826 1.223 1.062 1.031 1.561 1.760
9 6.891 5.509 5.391 4.481 3.370 2.548 1.778 1.253 1.049 1.041 1.500 1.735
10 6.583 5.953 5.223 4.536 3.334 2.442 1.685 1.316 1.044 1.032 1.486 1.726
11 6.427 5.950 5.218 4.505 3.327 2.393 1.733 1.487 1.048 1.023 1.434 1.702
12 6.429 7.114 5.384 4.837 3.314 2.361 1.743 1.455 1.037 1.032 1.368 1.676
13 6.807 6.929 5.286 4.999 3.272 2.289 1.737 1.405 1.029 1.005 1.334 1.686
14 6.390 6.032 5.220 4.651 3.224 2.234 1.758 1.324 1.013 1.035 1.320 1.654
15 6.207 5.790 5.282 4.560 3.180 2.208 1.718 1.304 1.002 1.041 1.287 1.639
16 5.976 5.605 5.242 4.504 3.017 2.167 1.685 1.281 0.999 1.025 1.284 1.653
17 5.963 5.451 5.111 4.421 3.046 2.142 1.623 1.238 0.972 1.037 1.351 1.674
18 5.917 5.684 5.076 4.347 3.082 2.106 1.599 1.200 0.956 1.069 1.497 1.699
19 5.879 5.481 5.027 4.342 3.145 2.084 1.541 1.161 0.933 1.098 2.199 1.780
20 5.786 5.196 5.027 4.287 3.074 2.141 1.534 1.139 1.016 1.094 3.094 1.806
21 5.680 5.141 5.142 4.243 3.033 2.129 1.495 1.158 1.000 1.129 2.621 1.790
22 5.653 5.212 5.304 4.263 3.103 2.101 1.470 1.204 0.999 1.112 2.088 1.782
23 5.736 5.292 5.491 4.714 3.127 2.069 1.493 1.265 0.998 1.082 1.856 1.762
24 5.833 6.374 5.276 4.994 3.272 2.034 1.449 1.305 1.024 1.082 1.967 1.743
25 5.777 7.118 5.437 4.423 3.255 2.010 1.461 1.377 1.032 1.107 2.329 1.714
26 5.512 6.575 6.746 4.201 3.139 1.991 1.334 1.396 1.049 1.126 2.129 1.711
27 5.350 6.050 6.127 4.041 3.139 1.922 1.323 1.381 1.038 1.258 1.943 1.631
28 5.299 5.822 5.731 3.959 3.033 1.887 1.341 1.291 1.016 1.312 1.850 1.615
29 5.254 5.619 5.381 3.897 2.979 1.895 1.349 1.231 1.018 1.196 1.973 1.604
30 5.212 5.282 3.970 2.781 1.871 1.347 1.198 1.057 1.146 2.052 1.594
31 5.166 5.190 2.692 1.336 1.176 1.138 1.535
Average 5.581 5.632 5.380 4.514 3.271 2.253 1.627 1.282 1.039 1.081 1.715 1.755
Lowest 4.297 4.753 5.027 3.897 2.692 1.871 1.323 1.139 0.933 1.005 1.124 1.535
Highest 6.891 7.118 6.746 5.105 4.013 2.774 1.966 1.487 1.156 1.312 3.094 2.224
Monthly total
(million cu m) 14.95 14.11 14.41 11.70 8.76 5.84 4.36 3.43 2.69 2.89 4.45 4.70
Runoff (mm) 46 44 45 36 27 18 13 11 8 9 14 15
Rainfall (mm) 59 69 52 46 41 24 21 63 21 60 123 26
Statistics of monthly data for previous record (Feb 1965 to Dec 1995)
Mean Avg. 5.544 6.302 5.539 4.660 3.550 2.706 2.009 1.674 1.602 1.936 2.613 4.055
flows: Low 1.249 1.237 1.207 1.083 0.871 0.652 0.492 0.388 0.670 1.014 1.137 1.421
(year) 1976 1976 1976 1976 1976 1976 1976 1976 1976 1989 1973 1990
High 10.630 13.860 9.208 7.571 5.249 4.345 3.104 2.438 2.598 3.681 6.395 9.427
(year) 1994 1990 1995 1979 1979 1979 1971 1979 1974 1993 1974 1992
Runoff: Avg. 46 47 46 37 29 22 17 14 13 16 21 34
Low 10 10 10 9 7 5 4 3 5 8 9 12
High 88 104 76 61 43 35 26 20 21 30 51 78
Rainfall: Avg. 83 55 64 48 56 56 50 59 70 70 74 87
Low 14 5 14 1 8 3 15 7 11 4 31 17
High 169 147 150 100 121 143 113 152 179 161 185 160
Summary statistics Factors affecting runoff
1996
For 1996 For record As % of $ Flow influenced by groundwater abstraction
preceding 1996 pre-1996 and/or recharge.
Mean flow 2.919 3.501 83
Lowest yearly mean 1.475 1976
Highest yearly mean 4.580 1994
Lowest monthly mean 1.039 Sep 0.388 Aug 1976
Highest monthly mean 5.632 Feb 13.860 Feb 1990
Lowest daily mean 0.933 19 Sep 0.183 22 Aug 1976
Highest daily mean 7.118 25 Feb 22.210 4 Feb 1990
10% exceedance 5.529 6.736 82
50% exceedance 2.066 2.836 73
95% exceedance 1.027 1.165 88
Annual total (million cu m) 92.31 110.50 84
Annual runoff (mm) 285 341 84
Annual rainfall (mm) 605 772 78
{1961-90 rainfall average (mm) 745}
Station and catchment description
Crump profile weir (crest 9.14m broad) flanked by broad-crested weirs. Small bypass channel approx. 2m u/s of weir -
included in rating. Full range station. During summer, flows are naturally augmented from gw draining from northern half
of R. Bourne catchment. May go non-modular at low flow in exceptional summers. Some gw pumping also takes place within
the catchment. Data reprocessed in 2001, resulting in decrease in high flows.
Predominantly permeable (Chalk) catchment with a small inlier of Upper Greensand and Gault. Land use: rural.
Topographical and gw catchments do not coincide.
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.