Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4722184 | Physics and Chemistry of the Earth, Parts A/B/C | 2006 | 6 Pages |
Environmental flow requirements for the Rusape River, a tributary of the Save River, in Zimbabwe, were estimated using a rapid results approach. Thirty years of hydrological data with daily time steps from gauging stations upstream and downstream of the Rusape Dam were analysed using DRIFT Software. The dam appeared to have caused an increase in intra-annual and inter-annual flood events downstream compared to upstream, including significant dry season releases, while inter-annual floods were larger. The water releases from the dam differ from the natural flow in both volume and frequency, especially in the dry season and may have had a negative impact on the local ecosystem and subsistence farmers.The building block method (BMM) was applied, using the hydrological analyses performed, in order to estimate environmental flow requirements, which are presented in mean monthly flows. The flow regime that is recommended for the Rusape River should reduce or reverse these impacts, whilst ensuring sufficient water resources are released for economic needs. The EFR proposed can be achieved within mean monthly flows observed. However, it should be stressed that the EFR proposed have been developed from a rapid method, and are only a first estimate of the EFR for the Rusape River. This study represents a step in developing a management plan for the Save Basin, shared between Zimbabwe and Mozambique.