Assessment of Reservoir Filling Efficiency of Medium Irrigation Projects in Telangana State, India for Enhancing the Water Use Efficiency
B. Krishna Rao *
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
V. Anil Kumar Reddy
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
A. Sailaja
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
K. Sunitha
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
K. Yella Reddy
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
M. Sachin Dutt
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
Ch. Krishna
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
P. Sravanthi
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
J. Tirupathi
Irrigation & Command Area Devt. Dept (Taliperu Project), Bhadrachalam-507115, Telangana, India.
N. Subhasree
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
Annie Maria Issac
National Remote Sensing Centre (NRSC), Hyderabad-500037, India.
B. Sumanth Reddy
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
S. Annapurna
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
S. Pankaja Devi
Water & Land Management Training & Research Institute (WALAMTARI), Rajendra Nagar, Hyderabad-500030, India.
*Author to whom correspondence should be addressed.
Abstract
Reservoirs play an important role in regulating water availability for irrigation, particularly under variable hydrological conditions. The study assessed annual inflow variability, major water-balance components and reservoir filling efficiency of five selected medium irrigation projects in Telangana from 2009–10 to 2019–20. Secondary data on inflows, outflows, withdrawals, spillages and reservoir storage were collected from the respective project offices. Evaporation and seepage losses were estimated using water-spread area, evaporation data and prescribed seepage rates. Reservoir filling efficiency was calculated based on the maximum annual live storage attained relative to the designed live storage capacity. The results showed considerable temporal and spatial variation in annual inflows, with 2013–14 recording relatively high inflows across all five selected projects. Taliperu recorded the highest average reservoir filling efficiency of 97.11% with the lowest variability (CV 1.0%), followed by Vattivagu (95.31%), Sathnala (94.47%), Musi (89.11%) and Peddavagu (84.72%). Musi exhibited the highest variability (CV 11.2%), mainly due to exceptionally low efficiencies during 2014–15 and 2015–16. Higher inflows were associated with increased spillage, particularly in Taliperu, while seepage and evaporation contributed to continuous water losses. The findings indicate that reservoir filling efficiency is governed by the combined effects of inflow magnitude and distribution, storage conditions, reservoir siltation and water losses. Assessment of filling efficiency over multiple years provides useful information for evaluating storage utilisation, reservoir performance and overall water-use efficiency of the irrigation projects. Regular monitoring, structural maintenance, catchment treatment and improved water-level monitoring can support effective reservoir operation and better utilization of available water resources and thereby enhance water-use efficiency of the irrigation projects.
Keywords: Medium irrigation projects, Inflows, seepage loss, reservoir filling efficiency, water use efficiency