Reservoir site evaluation through routing

Abstract

Reservoir routing was conducted for site evaluation of a proposed surface reservoir to be located in an ungauged watershed. The study was part of an integrated approach to the development of the watershed. Nash's synthetic hydrograph technique was used in developing the unit hydrograph, from which the 25-yr, 24-hr storm hydrograph was obtained using convolution procedures. The rainfall excess on the watershed was determined using the Curve Number method while Muskingum's method was used for flood routing through the watershed. A weighted Curve Number of 73 (with potential storage of 94 mm) was obtained – which reflected the agricultural nature of the study basin. The reservoir characteristics were determined from the contour map of the site. Flow estimates were also made from the flood routing results. For the 25- yr, 24-hr storm; the peak inflow into the reservoir was 0.73 m3/s with a peak outflow of 0.43 m3/s, resulting in an attenuation of 0.30 m3/s, and a relative attenuation of 41.10%. Also; the reservoir would not be overtopped since the 99.54 m water elevation for the 25-yr, 24-hr storm was below the reservoir embankment top elevation.

Keywords:Reservoir routing

Journal of Modeling, Design and Management of Engineering Systems Vol. 3 (1) 2005: pp. 53-62