Hydraulics & Waterways
398890 - Adaptive Strategies to Compensate for Reservoir Sedimentation: Examples from Puerto Rico
Wednesday, June 6
10:30 AM - 12:00 PM
Location: Greenway CD
Reservoirs experiencing significant storage loss by sedimentation are typically managed
under operating rules developed many decades ago. More holistic management
strategies and modified operating rules can be used to adopt to sedimented conditions,
delaying the decline in water supply and hydropower benefits due to sedimentation.
Three different adaptive strategies are presented for reservoirs in Puerto Rico which
have experienced substantial storage loss.
At the Patillas irrigation and municipal supply reservoir a conjunctive use strategy has
been developed which modifies the reservoir’s operating rule to provide substantial
volumes of water for aquifer recharge while reducing reservoir spills to the sea, thereby
increasing the total combined yield from ground and surface water resources.
At Carraízo (Loíza) reservoir supplying San Juan, an operating rule was developed
which extracts water from both the reservoir and wells at variable rates, achieving a
higher firm yield than if each resource were operated independently.
The Dos Bocas - Caonillas reservoir cascade represents the island’s largest municipal
water supply and hydropower resource. Despite a 60% volume loss at Dos Bocas, a
revised operating rule was developed which, together with rehabilitation of sedimented
upstream diversion dams and tunnels, can sustain the system’s water supply firm yield
with an insignificant impact to power production.
All three cases focus on more efficient operation of existing infrastructure rather than
costly new project construction or sediment removal (e.g. dredging or flushing). These
types of adaptive strategies will have applicability worldwide to help combat the effects
of reservoir sedimentation in a cost-effective manner.