ANALYSIS OF THE SEDIMENTATION RATE IN THE BAGONG DAM, TRENGGALEK REGENCY

Abstrak

Bagong Dam is one of the dams in Trenggalek Regency where the construction of this dam is an effort to deal with
floods and drought in Trenggalek Regency. The dam is located in Pengkok hamlet, Sumurup village and Sengon
village, Bendungan sub-district, Trenggalek district, East Java province. The water catchment area (DTA) on the
Bagong river has a steep slope which can result in reduced productivity of water absorption which in turn can cause
quite bad sedimentation. The amount of sedimentation can be estimated by calculating the rate or sediment transport
that occurs at the location to be reviewed. Based on the results of the analysis of calculating the sedimentation rate
using three methods, namely the Yang method, the Ackers-White method and the Engelund Hansen method
respectively, the calculation of the sedimentation rate is 4.185,84 m³/year for the Yang method, 16.302,36 m³/year for
the Ackers-White method , and 24.281,4 m³/year for the Engelund Hansen method. From the results of a comparison
with project planning data, the Yang method has the smallest difference with project planning data, namely 1.646,93
m³/year, while the Ackers-White method has a difference of 10.469,59 m³/year and the Engelund Hansen method has
a difference of 18.448,63 m³/year. From the three methods, namely the Yang, Ackers-White and Engelund Hansen
methods, the service life predictions of the reservoirs were obtained for 101 years, 26 years, and also 17 years
respectively