Hillsboro mistakenly discharged over 1 billion gallons of water
The Hillsboro Water Department accidentally diverted more than a billion gallons of water out of the Barney reservoir and into the Trask River last month due to a staff gauge malfunction, city officials say.
Thanks to heavy rainfall and forecasts for the rest of fall and winter, officials say there should still be plenty of drinking water to go around in town, and repair costs are expected to be minimal.
The error was discovered in October, when Hillsboro staff began investigating why stored water reports for the Barney Reservoir, located in rural Washington County, were below average. There weren't any leaks, but rather an issue with the system that measures and regulates water levels.
"The reservoir's levels and flow rates are automatically measured with telemetry at the site and recorded throughout the day," said Lindsay Wochnick, a city spokesperson. "Through the investigation, staff determined that a flow measurement error caused about 4,197 acre-feet of water to be unintentionally released down the Trask River."
Acre-feet is the measurement used to represent how many gallons fit into an acre of space in large reservoirs like Barney and Scoggins Reservoir at Hagg Lake.
That 4,200 acre-feet amounts to about 1.3 billion gallons of water.
City officials initially worried that the Hillsboro Water Department would need to lease extra water capacity from the nearby city of Forest Grove to make up for this faulty discharge. The utilities commission recently approved an extra 500 acre-feet of water capacity from Forest Grove for $33,550.
However, because of high natural flow in the upper Tualatin River, on which cities like Hillsboro are reliant for drinking water until the $1 billion-plus Willamette Water Supply Project is completed, Hillsboro says it shouldn't have to lease any more water from Forest Grove to offset the flow error.
"Because of forecasted rains, Hillsboro Water does not expect to lease more capacity," Wochnick said. "As of today, leasing would only be needed for Hillsboro if river levels decrease and the Joint Water Commission is placed back on regulation and stored water. The JWC partners plan for worst-case scenarios to ensure water supplies are available for our communities."
During summer months, typically beginning in June, the Tualatin River drops too low for community use, Wochnick said. When that happens, Hillsboro customers rely on the stored water in the reservoirs. The Barney Reservoir is in the Trask River watershed, nestled in the Coast Range. It can hold 20,000 acre-feet of water when full.
About 14,800 acre-feet is available for drinking water, and a 6,500-foot, 32-inch pipeline diverts the water that's put into the Trask River into the Tualatin.
During summer months, known by water experts as "release season," water from the reservoirs is released down the river to feed into the water systems of all the cities and agencies that make up the Joint Water Commission: Beaverton, Hillsboro, Forest Grove and the Tualatin Valley Water District, as well as Clean Water Services, a separate county agency that also shares ownership of the reservoir.
When natural river flows are low and reservoirs are the only source of reliable water, the JWC regulates how much can be diverted from the reservoirs and into the rivers.
However, the JWC took the Barney Reservoir off regulation at the beginning of November, since natural river flows are high enough to meet demand.
Hillsboro staff estimates that the cost to repair the faulty meter that caused the error will be $1,000 to $2,000.
If additional water capacity is needed to be leased from Forest Grove, it will happen in 500 acre-feet increments.
Hillsboro and Beaverton are both working to tap the Willamette River as a new drinking water source through the Willamette Water Supply Project. Costs of the project are currently estimated at over $1.6 billion.
Hillsboro water customers' utility bills are set to increase starting next year to help pay for that project. More details on the water cost increases can be found in previous Pamplin Media coverage, and on the city of Hillsboro's website.
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