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