At the weekly Emergency Operations update, local officials noted more of the same in terms of flood mitigation as snow in the mountains has still not begun melting the unprecedented, historical snow depth in the Sierras and the Carson River watershed.
According to reports, there is still some room for soil saturation upstream, in fact slightly more than had been projected in the past weeks. The Carson River is flowing at 3,610 cubic feet per second at the Ft. Churchill gauge into the Lahontan Reservoir and is expected to hit a 6,500 cfs flow rate in early May.
Flowing out of the river below the Lahontan dam, officials are keeping the river limited to 2,590 cfs to prevent damage and flooding to the residents along the river through the Lahontan Valley.
To increase the amount of water that can be released from the reservoir and meet the expected inflows, a second weir (used to control the flow of water for outlets in lakes and ponds, in this case through the V-Line Canal toward Sheckler Reservoir) is being constructed next to the one originally built in 2017 during that high-water year. The original weir has been flowing since early February when flood control measures began and is currently running at 750 cfs.
The second weir is expected to be completed in mid-May, with construction crews working round the clock, and can support another 3,500 cfs from Lahontan into the system.
In theory, that will provide a system of the river and the two weirs draining water as fast as water is coming in from the Carson River and is intended to prevent flooding along the Carson River.
While huge inflows are expected in May and June into Lahontan, all efforts are focused on preventing water in the reservoir from coming over the flashboards, which would mean uncontrolled water flowing in the Carson River below the dam. The reservoir can hold nearly 304,000 cfs when the flashboards are in place.
Currently, Carson Lake is expanding as water from the reservoir flows through the weir, through Sheckler Reservoir, and out to large culverts that flow under Highway 95 and to the Nevada Department of Wildlife controlled lake, famous to those bird watchers from across the country.
Snow maps are showing that the snow levels are still very high in the mountains. In anticipation of the huge amounts of flows predicted as a result of the snowmelt, sufficient capacity is being kept in Lahontan to cope with the surge of expected water. Flows are being controlled to release as much as is coming into the reservoir, but when the Carson River begins to rise, the water levels will fill Lahontan Reservoir.
The Churchill County Sheriff reports that his department has two boats that are launch ready and can be used for both Search and Rescue efforts as well as debris removal. There is also a Zodiac and other shallow draw boats available if needed.
All efforts being undertaken are focused on the protection of homes, farms, and critical infrastructure in the community.
The High Water Call Center continues to provide non-emergency resources for citizens seeking information about potential flooding. (Open M-F 8 a.m. to 5 p.m.). Call Center Phone: 775-867-5923.
We will continue to update this story.
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