53004 - Chew at Compton Dando

Grid Reference:31 (ST) 648 647
Operator:EA
Local number:531450
Catchment Area:129.5 km2
Level of Station:16.8 mOD
Max. Altitude:305.0 mOD
Mean flow:1.18 m3s-1
95% exceedance (Q95):  0.34 m 3s-1
10% exceedance (Q10):   2.353 m3s-1
61-90 Av. Ann. Rainfall:  988 mm

Sample Hydrograph of Gauged Daily Flows

Flow Duration Curve for Gauged Daily Flows

Station Description

Trapezoidal critical depth flume in deeply incised channel 5-6 m deep. Full range station but overestimates flows above 2m owing to backing-up. Flow record unreliable for a year after the July 1968 flood due to bank collapse and accumulated debris. The peak flow associated with the event is listed as 226 cumecs on the Hiflows-UK database bu this may be overestimated due to significant extrapolation and debris in the flume. Rating reviewed Jan 2001; new rating applied replacing previous theoretical rating from start of record. Ultrasonic gauge installed November 2007. Large storage reservoir of Chew Valley Lake in headwaters. Flows significantly affected by compensation flows and surface water abstractions for public water supply and industry. Monthly naturalised flow series available to 1980.

Catchment Description

Catchment of mixed geology - predominantly clay. Headwaters fed by limestone springs. Steep valleys downstream of reservoir on impermeable Coal Measures. Land-use: rural.

Factors Affecting Runoff

River Flow and Catchment Rainfall on the National River Flow Archive

Gauged Daily Flows (gdf):1958 to 2008
Naturalised Daily Flows (ndf):1977 to 1980
Naturalised Monthly Flows (nmf):1958 to 1980
Monthly Catchment Rainfall (rnf):1957 to 2008
                                                                     
Datatype1950s1960s1970s1980s1990s2000s
gdf           
ndf        
nmf            
rnf          
                                                                     

For many stations monthly peak flows are also archived. When daily flow data are not available monthly mean flows may be held on the National River Flow Archive. See Data Holdings for further information.

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