Management in Water sector
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ANNA MICHAEL MGIMBA, LIVINGSTONE M. SWILLA, WILLIAM SENKONDO
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20 November 2025
11
5
Numerical Evaluation of the Mtibwa Sugar Estates Earthfill Dam Safety, in Turiani-Morogoro,Tanzania.
DOI:
https://doi.org/10.56542/w.jwempo.v2.i2.a3.2025
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Keywords:
Earthfill dam; Dam safety; Seepage analysis; Slope stability; GeoStudio; Mtibwa dam.
Abstract
Earthfill dams are vital for water supply, irrigation, and flood control, but their safety can be threatened by structural weaknesses and poor maintenance. This study evaluates the safety of the Mtibwa Sugar Estates Earthfill Dam in Turiani, Morogoro Region that supports irrigation and economic development but limited monitoring raise stability concerns, necessitating safety measures to protect livelihoods. The assessment combined field reconnaissance, geotechnical laboratory testing of dam materials, and numerical modeling using GeoStudio 2023.1. Seepage through the embankment was analyzed using SEEP/W, while slope stability was assessed with SLOPE/W. Results showed soil permeability ranging from 2.25×10^-10 to 1×10^-2m/s, cohesion between 0 and 173 kPa, friction angles of 9.28°–38°, and moisture contents of 10%–30%. These values indicate a clay core with low permeability suitable for seepage control, supported by shell and drain materials that allow adequate drainage. Variations in strength parameters reflect both weak clayey and stronger sandy layers, influencing stability. Seepage discharge was 4.54×10^-6 m/sec, while slope stability analysis yielded a factor of safety of 1.566, confirming stable slopes. The study recommends improved drainage, monitoring systems, periodic stability assessments, and stronger dam safety management.
