027002    Wharfe at Flint Mill Weir                                                                                1985


           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        12.690   55.030    5.995   42.270    5.973    6.561    3.357   10.050   23.040    6.751    4.599   21.340
          2        10.630   30.960    5.983   28.110    5.509    5.917    3.145    9.691   22.390    6.346    4.396   31.110
          3         9.327   21.780    7.063   24.110    5.156    5.496    3.007   19.120   52.440    9.288    3.973   31.210
          4         8.652   19.710   18.390   35.750    4.986    5.163    2.886   46.030   38.250   12.570    3.972   17.770
          5         8.130   15.330   13.550   38.710    5.275    4.903    2.688  124.400   23.960    8.790    9.781   15.060

          6         8.010   12.820    9.603   25.160    5.455    4.663    2.555   35.310   15.940   34.850   13.610   21.540
          7         7.882   11.550    8.955   36.000    5.505    4.857    3.004   20.210   12.410   43.190   24.450   35.810
          8         7.343   10.660    8.461   39.580    5.084    5.110    2.942   15.500   34.620   36.850   27.390   32.660
          9         6.994    9.154    7.195   25.920    4.737    5.068    2.608   15.160   18.370   49.730   75.200   18.300
         10         6.874    7.988    6.547   21.120    4.557    5.036    2.554   10.480   12.860   27.090   48.780   14.000

         11         6.552    7.619    6.132   87.740    4.376    4.765    2.585   18.810   10.150   31.480   20.320   14.130
         12         6.024    7.372    5.771   56.630    4.247   36.820    5.899   46.250    8.882   16.720   12.680   15.580
         13         6.093    7.039    5.721   51.040    4.243   14.610   19.400   20.700    7.670   12.290    9.735   55.840
         14         5.900    6.697    5.433   49.320   12.270    8.784    9.530   22.670    7.161   10.070    8.967   30.440
         15         5.652    6.369    5.195   27.540   35.680    6.819    5.953   38.730    8.017    8.816    9.640   26.380

         16         5.261    6.052    5.140   19.600   16.530    5.581    4.441   50.150   17.400    7.969   12.560   20.860
         17         5.172    5.784    4.990   15.600    9.995    4.960    4.518   22.080   28.340    7.288   17.450   17.050
         18         4.655    5.455    4.761   12.940    7.932    4.424    5.952   15.030   13.820    6.650   11.590   24.830
         19         4.280    5.241    4.711   11.390    7.139    4.485    5.744   18.510   15.110    6.195    9.727   21.730
         20         4.328    5.205    4.643   10.060    6.684    4.164    9.104   34.180   11.830    5.745    8.708   44.330

         21        17.160    5.339    4.529    9.207    6.531    4.340   10.400   28.270   59.590    5.469    7.949  165.700
         22        40.690    5.501    5.341    8.669    5.989    5.654    9.361   17.420   78.780    5.474    7.542   93.410
         23        26.810    6.520   15.200    7.891    5.614    8.949   12.790   14.250   33.110    5.207    8.220   42.270
         24        17.800   11.330   17.590    7.375    8.103    9.562    6.836   54.110   26.820    5.123   13.210   30.240
         25        12.140    8.160   12.400    6.881   14.830    6.474    5.922   48.130   16.070    4.886   11.210   25.470

         26        10.260    7.679   10.750    6.517   20.260    5.166   31.560   31.110   12.630    4.582    9.378   21.730
         27         9.127    7.070    8.583    6.261   14.630    4.520   47.950   18.330   11.980    4.299    7.912   16.480
         28        16.480    6.107    7.199    6.167   22.760    4.243   21.800   28.840    9.483    4.173    6.979   12.970
         29        71.630            15.450    6.403   12.640    3.818   32.900   17.920    7.971    4.256    6.367   10.660
         30        67.830            40.790    6.324    9.260    3.593   25.750   12.890    7.235    4.009    6.470   10.160
         31        71.000            18.510             7.538            14.450   11.080             4.324            18.460
 


 Average           16.170   11.270    9.696   24.340    9.338    6.817   10.370   28.240   21.540   12.920   14.090   30.890
 Lowest             4.280    5.205    4.529    6.167    4.243    3.593    2.554    9.691    7.161    4.009    3.972   10.160
 Highest           71.630   55.030   40.790   87.740   35.680   36.820   47.950  124.400   78.780   49.730   75.200  165.700

 Monthly total
  (million cu m)    43.32    27.26    25.97    63.10    25.01    17.67    27.79    75.64    55.84    34.60    36.53    82.73


 Runoff   (mm)       57       36       34       83       33       23       37      100       74       46       48      109  
 Rainfall (mm)       89       14       74      108       90       58      123      173       96       65       90      148  


 Statistics of monthly data for previous record  (Oct 1955 to Dec 1984)

 Mean      Avg.    27.930   23.580   21.440   15.190   11.320    7.544    7.565   11.180   13.630   18.320   24.020   27.190
 flows:    Low      4.472    2.974    6.741    4.496    2.312    1.545    1.674    0.991    1.419    3.026    6.876   10.230
           (year)    1963     1963     1961     1974     1980     1957     1976     1976     1959     1972     1958     1963
           High    44.000   54.590   53.940   35.240   26.750   18.530   16.440   41.340   33.520   54.000   51.090   62.090
           (year)    1984     1966     1981     1970     1967     1972     1963     1956     1968     1967     1963     1965

 Runoff:   Avg.      99       76       76       52       40       26       27       39       47       65       82       96  
           Low       16        9       24       15        8        5        6        4        5       11       23       36  
           High     155      174      190      120       94       63       58      146      115      191      174      219  

 Rainfall: Avg.     114       83       89       72       77       76       82       97      107      107      114      121  
           Low       41       20       28        8       13       18       20       18        8       32       33       41  
           High     217      194      222      147      181      183      185      226      241      225      211      233  


 
 Summary statistics                                                           Factors affecting runoff
                                                                    1985
                                   For 1985       For record        As % of   $ Reservoir(s) in catchment.
                                                  preceding 1985    pre-1985  $ Abstraction for public water supplies.
 Mean flow                       16.340          17.390                  94   $ Flow reduced by industrial and/or
 Lowest yearly mean                              11.420        1975             agricultural abstractions.
 Highest yearly mean                             23.300        1966           $ Augmentation from surface water and/or
 Lowest monthly mean              6.817    Jun    0.991    Aug 1976             groundwater.
 Highest monthly mean            30.890    Dec   62.090    Dec 1965
 Lowest daily mean                2.554 10 Jul    0.425 23 Jun 1957
 Highest daily mean             165.700 21 Dec  288.400  3 Jan 1982

 10% exceedance                  36.380          41.500                  88
 50% exceedance                   9.542           9.675                  99
 95% exceedance                   4.206           2.233                 188
 Annual total (million cu m)     515.30          548.80                  94
 Annual runoff (mm)               679             723                    94
 Annual rainfall (mm)            1128            1139                    99
         {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.