Jensen Grove too low for water sports this summer
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BLACKFOOT — Jensen Grove, usually a popular recreational summer hangout, won’t be full in time for this year’s Celebrate Blackfoot water events on Saturday, June 28, and likely won’t be full at all this summer.
When the water levels are healthy, the 55-acre lake is a hub for boating, water skiing, jet skiing, swimming and fishing.
Blackfoot Mayor Mark Carroll said the water level is too low for motorized water sports, and all such activities planned for the event have been canceled. Non-water events for Celebrate Blackfoot will go as planned.
While fishing, kayaking, canoeing and playing in the shallow water are still permitted at individual discretion, the lake lacks sufficient depth to support larger watercraft.
Jensen Grove is typically filled by water diverted from the Snake River, with some additional runoff coming from the Corbett Slough canal. But this spring, weather-related challenges and damage to the city’s water diversion system have left the lake mostly dry.
Carroll explained that current water priorities are based on agricultural needs, not recreational needs such as those at Jensen Grove. No water is expected to be released for lake use until the end of July, and even then, filling the lake would take approximately a month.
Water District 1, located in Idaho Falls, manages the agricultural water on the Snake River. The district oversees irrigation and streamflow distribution from the river to farmlands and canals in the region, including the Snake River (upstream of Milner Dam) and its tributaries.
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“It’s unlikely we’ll see the lake full this summer,” said Carroll. “The watermaster is not projecting to send any water down the river till the end of July due to the water calls coming out of Twin Falls. And we really can’t say when that might change.”
District 1 Watermaster Craig Chandler confirmed this, saying, “I understand that there have been some diversion dam problems getting water into Jensen Grove. Their water rights have also been cut and there won’t be water rights available for the rest of the year.”
Heavy flows from the Snake River nearly filled the lake earlier in the season, thanks to flood mitigation releases from Palisades Reservoir. However, the fast-moving water also damaged the city’s diversion dam, washing out key areas, creating sandbars, and clogging the intake culvert with silt. The damage wasn’t initially apparent because the high river level temporarily masked the problem.
By late May, the Idaho Department of Water Resources scaled back the river flow from Palisades, since the flood danger had passed and snowpack levels were lower than expected. As a result, the Snake River’s flow dropped significantly, falling to around 1,500 cubic feet per second. A minimum of 5,000 cubic feet per second is needed to fill the lake slowly, and ideally, the flow would be closer to 7,000 cubic feet per second.
Carroll acknowledges that the lake’s lack of water has been an ongoing problem for the past few years, saying, “I can’t tell you the number of hours that the city has spent on this problem. We’ve determined that the 30-year-old diversion system has outlived its usefulness, and we are working on a long-term solution.”
The long-term solution includes repairing the damaged diversion dam and installing a pump system with a generator to help move water from the river, even during low-flow periods. This project will require collaboration with the Idaho Department of Water Resources, the Bureau of Reclamation, and the Army Corps of Engineers.
“Our goal is to have the new setup in place by early next year — but a lot depends on Mother Nature. Sometimes she’s good to us and sometimes she isn’t,” said Carroll.
For now, Jensen Grove visitors can enjoy what little water remains in the lake and are encouraged to plan on land-based activities for this year’s Celebrate Blackfoot and the foreseeable future.