Planning Advice Note PAN 69
Planning and Building Standards Advice on Flooding
CASE STUDY 2
WHITE CART WATER: A catchment management approach to flood prevention
The White Cart Water is one of the major tributaries of the River Clyde. It is a 'flashy' river, meaning that the water level can rise very quickly: just 12 hours of rainfall are capable of causing water levels to rise by almost 6 metres. Over the last century the White Cart has burst its banks more than 20 times, with serious flood events in 1984, 1994 and 1999. The majority (around 90%) of the White Cart's flow that passes through Glasgow originates from outwith the city boundaries.
To address this situation Glasgow City Council has adopted an integrated catchment management approach to consider flooding, environmental and other related issues. Central to this is the optimisation of flood water storage in the upper catchment, allowing flood defence walls within the city to be limited to an acceptable height, helping to limit the impact on existing wildlife habitats and avoid creating barriers between the river and the community. The alternative approach would be a 'walls only' solution, which would result in the construction of unacceptably high walls along the urban corridor of the river.
The scheme, designed to guard against the 0.5% (1:200) flood event, will work by allowing large basins within the rural areas of the upper catchment to flood during heavy rains. The proposed measures include three new water storage sites at Blackhouse near Newton Mearns, Kirkland Bridge near Eaglesham, and Kittoch Bridge near Carmunnock. The largest of these storage areas, at Kirkland Bridge, will have the capacity to hold almost 1 million m 3 of water (during a 0.5% (1:200) event) and will cover more than 42 hectares. The storage sites will remain dry for most of the year. In addition to the storage areas, there will also be 7.6km of wall along the banks of the river within the city boundary.
Stakeholder involvement
Glasgow City Council recognised the importance of involving the main stakeholders in progressing the scheme. A Steering Group and working groups were established to help develop the scheme, allowing local authorities in the upper catchment and environmental agencies to have input to the scheme from the early stages through to its final form. This proved to be a vital factor ensuring that planning and environmental constraints were identified at an early stage. It also ensured that opportunities for environmental, development and recreational benefits were considered, as well as mitigation being built into the project.
 |   |
White Cart Water: previous flood events (Photos courtesy of Glasgow City Council) | White Cart Water scheme - Local authority's preferred location of flood storage areas |
For more information about the White Cart FPS, contact Glasgow City Council on 0141 287 8607.