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Drought causes historic disruption at hydropower plant

August 6, 2021

On 5 August, the California Department of Water Resources (DWR) took offline the 750-MW Hyatt Powerplant. DWR director Karla Nemeth cited “record-low reservoir levels due to dramatically reduced runoff this spring.” The disruption is unprecedented since the generating station began operating in 1967.*

DWR anticipated the dire situation at Lake Oroville. With the possibility of losing the asset, the agency informed the California Independent System Operator (CAISO) and the California Energy Commission. These organizations work with the California Public Utilities Commission (CPUC) to procure additional electricity to balance demand and supply.

Similarly Pacific Gas and Electric (PG&E) planned ahead. During the spring it implemented aggressive water storage and conservative water release strategies at its reservoirs.

Year-to-year water levels

Two years of below-normal precipitation seasons has demanded continual planning, coordination and improvement to meet water allocations for domestic water supply and fish as well as generating waterpower.

Managing heatwaves and extended periods of extreme temperatures also involves a high level of coordination and communication without disruption to hydropower generation. Waterpower continues to provide operational flexibility as robust sources of solar and wind power scale.

Water flows across the West

The National Hydropower Association noted “hundreds of hydro plants throughout the West have continued to generate (electricity and deliver water. They are) a testament to the efforts of the owners and managers of reservoirs and generating facilities.”

In Idaho, Hydro Review reported that Avista Utilities expects discharge at the Post Falls Hydroelectric plant to drop to the minimum of 500 cfs due to low rainfall and uncharacteristic heat. The reduction is the least amount permissible by 2009 license issued by the Federal Energy Regulatory Commission (FERC). The reduced flow is expected to be compliance, in order to maintain the Coeur d’Alene Lake water level and Spokane River flows.

KISTERS provides reliable IT innovations to meet the demands of operating reservoirs and hydro plants in a changing world. The combination of instruments that monitor snowpack, rainfall and water flow and software to analyze hydromet data. Further ensure that electric load requirements and flow obligations are met with hydropower operator-driven optimization modeling; create near-term generating schedules that meet regulations. 

* Some people may recall that heavy rainfall in February, 2017 damaged Oroville Dam’s main and emergency spillways. Rain raised the lake level till water flowed over the emergency spillway, while headward erosion threatened to collapse the weir and send a 30-foot (10m) wall of water downstream.