Assessing Climate Change Impact on System-wide Water Allocation Trade-offs for California's San Joaquin River System
Abstract
Hydropower will play an increasingly important role as California develops more stringent energy and environmental goals, but its production is highly sensitive to hydroclimatic conditions. Atmospheric temperatures in the region are expected to increase from 1.4o C to 4.9 o C in the coming decades and, combined with increased variability in precipitation and widespread reduction in snowpack, hydropower production will need to adapt to a less reliable hydrologic regime. California's complex geographic, hydrologic, and regulatory operational space requires continual evaluation of trade-offs between water/energy storage and production, and downstream demands including ecosystems. To better understand trade-offs between optimal water-energy system operations and downstream regulatory contingencies, we developed a benefit-maximizing linear programming-based hydropower optimization model that considers existing policy and physical constraints in system operations, thus mimicking actual operator release decisions. Policy constraints include flood control curves and downstream demand. Operational constraints are built-in as reservoir release rules. To develop the model, we used Pywr, a Python-based linear programing optimization package, linked with OpenAgua, a web-based modeling platform used for data input and visualization. Energy benefits were derived from the HiGRID statewide energy production and demand model. Future hydroclimatic variations were from bias-corrected Variable Infiltration Capacity (VIC) generated runoff and from four CMIP5 GCMs using the RCP 8.5 emissions scenario. We examine differential impacts on hydropower generation and operational capacity to meet future hydropower demands, along with meeting more stringent ecological flow requirements in the future. To represent upper and lower limits for downstream flow requirements, seasonally varying ecological flow demands and with piecewise linear costs (demand-cost blocks) were built into the model. We focus on the four major basins of the San Joaquin River, one of the primary water sources for California. This approach allows for systemwide evaluation of trade-offs in water and energy production, safeguards for ecosystems, and potential adaptation pathways to balance management priorities
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGC11H1077S
- Keywords:
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- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 1807 Climate impacts;
- HYDROLOGY;
- 1817 Extreme events;
- HYDROLOGY;
- 6344 System operation and management;
- POLICY SCIENCES