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Title: Lower Colne improvement scheme November 1995 : Shire Ditch and Colne Brook, Uxbridge
Author: National Rivers Authority Thames Region
Document Type: Monograph
The Lower Colne Improvement Scheme is an £18M river improvement scheme in the Lower Colne system of rivers, all tributaries of the River Thames. The River Colne catchment varies in shape, topography, land use and hydrological and hydraulic complexity perhaps more so than any other catchment in the Thames Region of the National Rivers Authority. The analysis of the system is therefore also complex, and the solutions to flooding problems, whether local or strategic, are rarely straightforward. The Colne river system drains 1000 km2 of land to the north west of the London conurbation, which is approximately 10% of the non-tidal Thames catchment to Teddington Weir. It has a fan shaped catchment, with chalk predominantly outcropping in the upper area whilst London clay underlies gravels in the narrow neck downstream of Watford/Rickmans worth. The catchment characteristics, with the majority of urban runoff received in the downstream reaches, creates long flat flood hydrographs not prone to rapid response or flash floods, with the total 1 in 100 year flood flow to the Thames in the order of 50 m3/s.
Publisher: National Rivers Authority
Publication Date: 1995
Publication Place: Bristol
Subject Keywords: RiversCatchment basinsImprovementFlood risk management
Geographic Keywords: EA South EastColne (Essex)Colne catchment
Extent: 9
Total file downloads: 298

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