Reservoir sedimentation is a serious challenge that reduces reservoir life. Because it decreases the initial capacity of the reservoir and has an impact on drinking water supply, irrigation, and hydropower activities. Inadequate land activities and poor management techniques cause soil erosion and reduce reservoir storage capacity. As a result, accurate sediment estimation was assist in the adoption of sustainable land-use activities and best management practices that lead to effective reservoir operations. The main objective of this study was to evaluate the rate of sedimentation and remaining capacity of Adebra night storage reservoir (NSR) using a bathymetric survey and Arc-GIS 10.8. A comparison of original and current reservoir capacity was used to evaluate the quantity of sediment deposition in the reservoir. The latter was developed using Arc-GIS 10.8 and a bathymetry survey that was used to develop the TIN surface and evaluate reservoir volume. The Adebra NSR reservoir capacity was decreased by the accumulation of sedimentation from 36,902 m3 in 2012 to 27,722 m3 in 2020. The results of this study showed that the Adebra night storage reservoir had lost on average 24.8% of its capacity due to sedimentation, during 8 years of operation. The average deposition rate of sedimentation in Adebra NSR was estimated to be 1147.5 m3/year, with a loss rate of 3.1% per year. The value of sedimentation rates found in live storage of the reservoir area was 1147.5 m3/year. At the current time, the expected life of the night storage reservoir was reduced due to a lack of proper soil conservation practices in the reservoir catchment areas. In general, the study finding showed that the capacity of NSR was reduced by the accumulation of sedimentation year to year throughout the design period. Therefore, to improve the capacity of NSR should be planning and implementing different techniques of sediment control and removal, depending on the estimation of sediment production from watersheds of inlets and outlets of reservoirs.

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Changes in Land Use Land Cover (LULC) are currently one of the greatest pressing issues facing the watershed, its hydrological properties of soil, and water management in catchment areas. One of the most important elements impacting streamflow in watersheds is LULC change. The main objective of this study was to evaluate the effect and future predication of LULC change on streamflow of the Fetam watershed by using Cellular Automata (CA)-Markov in IDRISI software. To analyze the impact of land use/cover change on streamflow, the Soil and Water Assessment Tool (SWAT) calibration and validation model was used. LULC map was developed by using Cellular Automata (CA)-Markov in IDRISI software, and the coverage of LULCs was including parameters of cropland, vegetation, grassland, Built-up area/Urban and water body. The findings of this study showed that the major challenges of land use/cove changes were rapid population increase, farming, and industrial activity. During the study period (2000–2020), most portions of the water body, vegetation, and grassland were changed into cropland and constructed by building. Cropland and construction areas increased by 15% and 46.95%, respectively, whereas water bodies, vegetation, and grassland decreased by 62.7%, 70.02%, and 38.1%, respectively. According to the forecasted results for the period of 2030–2040, cropland and built-up areas are increased, while vegetation, grassland, and water bodies were decreased. The SWAT model's calibration and validation performance was evaluated using the streamflow of the most sensitive parameters. For the years 2000–2004, and 2005–2012, the models were calibrated and validated, and the results showed good agreement between observed and simulated streamflow, with NSE and R2 values of 0.88 and 0.72 and 0.9 and 0.85, respectively. The results of this study indicated that the seasonal streamflow was decreased from 2000 to 2010 and 2010–2020 years during the dry and rainy seasons. In general, the impacts of land use/cover change on streamflow are significant considerations for planning and implementing water resource projects. In order to address the risks, effective land-use planning and climate-resilient water management strategies will be improved.

The hydraulic performance and future water demand of water distribution networks are major factors affecting the efficiency of water distribution systems throughout the world. Currently, Addis Kidam Town in Ethiopia is facing many water supply challenges. Their existing water distribution system is inadequate experiencing significant water loss, pressure, and flow velocity. All becoming worse with forecast population increases. The main objective of this study was to evaluate the hydraulic performance of the water distribution network considering both the existing water demand, together with forecast future water demand. The study was undertaken in Addis Kidam Town in Ethiopia using static analysis and WaterGEMS V8i software. The data were collected using experiment tests, field observation, focus group discussions, and interviews. Sampling sizes of pipes and junctions of distribution networks were used to evaluate velocity and pressure changes of 12% and 15%, respectively, from high and low-pressure zones. The results of this study indicated that the existing distribution network was designed to supply a population of 8,906; however, the current population was 25,854. The existing system can accordingly not meet current demand. The current system was only supplying 19.5 l/c/d to each family and was only able to supply 45.2% of households. All compounded because water loss of the distribution network was 37.9%. Simulation of existing distribution network at junctions and pipes has both 26.6% and 4.3%, and 2.4% and 29.9% lower pressures and velocities during peak and minimum hourly demand, respectively. Model performance values of RMSE, MAE, R2, and NSE of distribution networks were 0.65, 0.40, 0.96, and 0.82 and 0.56, 0.38, 0.98, and 0.78 during the calibration and validation of pressure, flow, and tank level, respectively. The research recommends a two-phase strategic water distribution system response beginning by upgrading and expanding the water distribution network, to first achieve a supply of 30 l/c/d by 2032, and then lifting this to the 30–80 l/c/d range before 2042. The proposed water management upgrading approach is expected to establish a good water supply for all residential communities of the town facing comparable challenges. In general, this study’s findings showed that the existing water supply system could not meet the present demand, let alone meet future growth demand. The existing modeling highlighted that significant increases in supply are possible by targeting system improvements, together with the need to find additional supply to meet both present and future water demand.

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