The National Rivers Authority is obliged under Statutory Instrument 1217, The Land Drainage Improvement Works (Assessment of Environmental Effects) Regulations 1988, to prepare an Environmental Statement if the environmental effects of proposed land drainage works are deemed to be significant. This Statement details the environmental impacts and mitigation measures for the Contract Cl improvement works to the River Wandle. It includes information on the purpose of the project, descriptions of alternative options and the proposed option, the existing environment and analysis of the predicted environmental effects and mitigation measures. These proposals form part of the wider Beddington and Mitcham Area of Opportunity Scheme (BMAO) designed to provide a 1:100 year level of protection by combining river works with flood storage areas. Contract Cl described here, involves interim works to the River Wandle from Beddington Park to Richmond Green. These will provide a 1:10 year level of flood protection for the immediate area. The works include the removal of restrictions, some channel and bank work, the creation of a flood relief channel and the replacement of a number of crossings. Alternative options such as major diversion channels and extensive enlargement of the existing channel were rejected both on environmental and engineering grounds.