There could be a flood this year in the spring, but Tooele City and county leaders are prepared.
As of Tuesday morning, Jan. 31, 2023, the peaks around the Tooele-Rush Valley Basin were holding 205% of the 30-year median value of snow water equivalent for the same day of the year, according to the National Resource Conservation Service.
Because of the high snowpack, some residents are wondering if spring flooding is a possibility.
“It is not possible at this point to accurately determine the degree of snow melt flooding that may or may not occur this coming spring,” said Jamie Grandpre, Tooele City public works director. “While the current snowpack is above average for this time of year, there are a number of factors that still must come into play.”
Several questions or factors, as Grandpre mentioned, must be considered when talking about a potential flood. He said these include; “Will the winter continue to add snow depth or will it taper off?” “How quickly will it warm up and will it stay warm?” and “What are the instream soil measure conditions?”
Flooding may also be a possibility when snow melt is directly driven from high temperatures or by heavy rain or snow.
Tooele City experienced significant flooding in the spring of 1983 and as a result, significant channel erosion and flooding within the city limits occurred.
“As a result of those floods, the city, county, and state made several improvements to the Middle Canyon and Settlement Canyon drainages as they pass through town,” Grandpre said. “The amount of snowpack in 1984 was actually higher than in 1983, but the amount of flood damage was reduced due to the mitigation measures that were undertaken.”
That brings us to drainage channels, he said.
“In order to help plan and mitigate flood potential, the city has adopted special floodplain hazard maps for both of these two drainages [Settlement and Middle Canyons],” Grandpre said.
Tooele City and the county also have several measures in place if a flood does occur.
“Focused flood measures typically begin in early spring,” Grandpre explained. “These measures include, but aren’t necessarily limited to; coordination within Tooele County Emergency Management, clearing off brush and debris from major drainage channels and pipes, and providing sandbags that can be used by residents for local flood control.”
Home and business owners can prepare themselves for floods, even though most floods on properties are a result of “self-flooding.”
Self-flooding results from improperly directing storm drains away from window wells or other openings, landscaping modifications, which do not allow runoff to properly flow away from structures, and leaving vehicles on the roadway, causing water to jump out of channels and follow the grade downhill during a high flow event.
“We encourage residents to look at their particular homes and to make adjustments to avoid flooding,” Grandpre said.
Residents who live adjacent to storm drainage channels or ditches should plan early to fill and place sandbags to keep water away from their homes.
“It’s too early to do this now, but should be considered later in the spring as storm water runoff begins and upon following weather reports, which would suggest flood risk,” Grandpre said, referencing the above.
The risk of flooding may be reduced due to dry soil conditions, according to Grandpre.
Links to higher-resolution of the above maps:
Middle Canyon – https://tooelecity.org/wp-content/uploads/2014/03/MiddleCanyonSpecialFloodHazardAreas.pdf
Settlement Canyon – https://tooelecity.org/wp-content/uploads/2014/03/SettlementCanyonSpecialFloodHazardAreas.pdf