Bugs Pay for Days of Steady Reservoir Releases to Reduce Costs to
Hydropower Customers and Sustain Funds to Maintain Infrastructure
Abstract
Steady low reservoir releases allow downstream aquatic invertebrates
(bugs) to lay and hatch eggs and increase production. These releases
also reduce revenue from hydropeaking operations, increase costs to
hydropower customers, reduce funds to maintain project infrastructure,
repay project loans, and exacerbate hydropower production-ecosystem
conflicts. This paper has the purpose to (1) quantify tradeoffs between
the number of days of bug flows and hydropower revenue, (2) identify
ways to reduce costs to hydropower customers, and (3) inform the design
of a financial instrument to increase bug production, compensate
hydropower customers for costs, and reduce conflict. A linear program
identified tradeoffs between hydropower revenue and number of days of
steady low releases per month for different contract and market energy
prices and monthly release volumes across March to October months when
bugs are most productive. We found that bug flows on 8 weekend days per
summer month in 2018 from Glen Canyon Dam, Arizona reduced hydropower
revenue by $300,000 (June) to $600,000 (August). Shifting bug flow
days to Spring/Fall months reduced costs. To reduce conflict, we suggest
creating a new financial instrument funded by the Federal Treasury for
~$300,000 to $600,000 per month. The instrument can
give ecosystem managers more flexibility to choose days for steady low
releases that advantage bugs and pay hydropower producers for costs.
Next steps are to engage Federal agencies on the benefits and
limitations of the proposed instrument and expand to steady high
releases that mobilize sediment, build sandbars, and disadvantage
non-native, invasive fish populations.