Assessment of groundwater reserves in Moshi Municipality aquifer using GIS

The current water resources in Moshi Municipality do not meet the demand. This is partly due to dynamic growth of industries and human development/urbanization. Major conflict in water uses in the area is between agriculture and hydropower development. In case of groundwater resource uses, there exist problems of identifying groundwater potential zones, flow patterns and quantifying the available groundwater reserves. This study therefore, aimed at assessing the Moshi Municipality Groundwater Reserves. Groundwater Potential model has been used to map groundwater potential zones and estimate borehole yields. Analysis was performed in spatial domain under a raster based Geographic Information Systems (GIS), where input hydro-geologic setting coverage/layers were overlaid. Other activities performed were aquifer characterization, determination of groundwater flow paths, and estimation of groundwater reserves. Results from GP model showed that the aquifer has a potential yield of 19,536 million3 m /yr. Estimated total groundwater reserve is 28,948.13 million m3. GP - model also revealed that mid and lower part of aquifer with volcanic and alluvium materials are zones of high groundwater prospects, while areas with red rocks on the east and northeast parts are low groundwater potential zones. Due to inadequacy of actual field data, this work finally propose detailed field data to be collected, for proper mapping of definite routes of groundwater flows and establishing groundwater management policy for optimum utilization of the groundwater reserve.