Improving the hydraulic efficiency of covered watercourses:


Prepared by:Mohamed Salah

Improving water quality is one of the main goals of the Ministry of Water Resources and Irrigation.Covering irrigation channels may be the solution to maintain protection of the watercourse environment from pollution and the preservation of public health of citizens especially close to residential areas. Also the need to use the land area occupied by watercourse for an access road or some other uses.Poor soil stability and bank failure may be also reasonable reason for covering open channels. Channel maintenance research institute (CMRI) has studiedmanycoverageson open channels along the irrigation network to determine their impact on its hydraulic efficiency.In addition, to identify the different impacts of coverage on the environment and water quality, improve the current state of these watercourses after coverage,determine the foundations and standards necessary to take decisions to cover the watercourse passing through the residential areas, andsuggest the proper maintenancemethods of covered channels. Coveragecross section can take several forms such as box section (square or rectangular) or Circular pipes.CMRI suggested a new approach for covering"semicircular cross section" which is characterized by being easy inmanual and mechanical maintenance, achieves higher hydraulic efficiency, and less hydraulic losses. CMRI has prepared a guide for the maintenance of coverages to serve as a guide for the engineers of different irrigation and drainage directorates to identify the different maintenance methods suitable for the coverage