Thurston County’s Nisqually Valley had no Pineapple Express or atmospheric river floods from Hawaii this fall and winter. Mother Nature sent this season’s storms to California. However, we don’t need to hope that our misery gets passed to other states in order to avoid it.
Most of the flooding in the Nisqually Valley from severe storms is the result of how the Tacoma Power Utility (TPU) runs Alder Lake Dam. They have no flood mitigation responsibilities in their Federal Energy Regulatory Commission (FERC) license. TPU’s goal is energy production.
They attempt to keep the reservoir as full as possible, even in fall and winter. Often, little action is taken even when the National Oceanic and Atmospheric Administration (NOAA) graphics (www.nwrfc.noaa.gov/river/station/flowplot/flowplot.cgi?ALRW1) predict a storm on the horizon.
NOAA produces three graphs that predict Alder Lake flood dangers 10 days in advance, with increasing accuracy until the storm hits. Simple evasive actions by TPU, (e.g., running the La Grande generators below Alder Dam at full capacity — 2,300 cubic feet a second — for a few days prior to a predicted storm), would easily avoid or strongly mitigate potential Nisqually floods. The reservoir would be lowered in a storm’s advance and all water would be passed through the La Grande generators below Alder Dam at no income loss.
Paying close attention to these graphic predictions would allow simple protection of the valley below the dam. This is becoming an even bigger issue as the proposal to rebuild Interstate 5 across the lower valley nears. This simple evasive action can be done at no financial disadvantage to TPU.
Howard H. Glastetter,
Olympia (Nisqually Delta)