Kubanni Impounding Reservoir was 2,600,000 m3 after construction in 1971 and impoundment in 1974. The Reservoir lost its storage capacity to 1,031,275 m3 of silt and the remaining storage was 1,568,725 m3 in 2008. The reservoir was dredged in the year 2014 and the measurement of its depth was done using both Manual and Echo-Sounding Technique to determine the new volume after dredging. Manual technique was done by the researcher and the Echo- sounding was done as a team by staff from Adalen consulting limited with the researcher ( for ABU Monitoring Committee ) in year 2015 after dredging. The result of the Manual Technique was 2,038,759.90 m3, while that of Echo-Sounding was 2,021,703.00 m3 making the difference on the value to be 17,056.90 m3. It was concluded that Kubanni Reservoir, as a small reservoir is best surveyed manually considering some irregularities such as ; not being able to access the area close to the shore of the reservoir with echo – sounding because of the calibration, while large and deep reservoirs are best surveyed with echo – sounding to avoid sliding of the metric tape by the water wave and also save time using manual measurement.

Keywords: Bathymetric Survey, Reservoir, Echo-Sounding, Manual Technique, Dredging, Storage Capacity, Measurement, Comparison.