Hydrological Assessment of Interconnected River Basins in Semi-Arid
Region of Peruvian Andes
Abstract
Freshwater is limited in the semi-arid Arequipa region in Southern Peru
that is home to more than 1.3 million people, agricultural and
industrial sectors. To address water demand, eight reservoirs and more
than 200 km of water diversion tunnels and canals have been implemented
in the Quilca and Camaná river basins, resulting in severely modified
hydrology and interconnection of the two basins. The Soil and Water
Assessment Tool (SWAT) was used to simulate the current hydrological
status and potential alternative management scenarios for the two
interconnected basins. Simulation challenges include scarcity of data on
soil and land cover to run SWAT, which was addressed by developing
publicly available regional soil and land cover databases. A
representation of water infrastructure required a complex model
structure incorporating point sources to represent water transfers and
reservoir outflows and water withdrawals at 17 locations. The developed
model is used to provide a comprehensive understanding of water
availability in the region under current and alternate scenarios for
water regulation. The impact of current water infrastructure on minimum
streamflow is explored in the Quilca and Camaná river basins. Results
were shared with the local water authorities and the public via an
online tool called HidroAQP to support water allocation and related
water resource decisions.