The snow run-off is expected to increase through the week. However, flood bulletins are not issued unless property damage accompanies the high water. Last week a canal in the Ranch Place neighborhood was overflowing a culvert and running into Cutter Lane. It was not a flood designation because the water flowed into a storm drain on the street.
NOAA, the National Oceanic and Atmospheric Administration uses models which have been built to include spring snow melt and the effects of the run-off on Utah’s waterways. NOAA Senior Hydrologist, Brian McInerny explains how a flood designation works.
“I set the flood stage for Utah. All these flood levels and then we refine them as we go along. If it’s causing damage to bridges and structures, monetary damage, then that’s flood stage. So, if the water is out of its banks and flowing around, that’s okay. Even if it goes over the road a little bit."
He says many rivers and canals are out of their banks across the state and it would be too many to chase. However, McInerny warns that the reservoirs like Deer Creek and Jordanelle can be very dangerous below the dams.
“They’re raging so big you need to stay away. So, we issue flood warnings for that reason also. People can die if you fall in. We already had that in 2017. A mother and her daughter were right next to the Provo River when they were releasing water out of Deer Creek. And, the kid fell in and the mom jumped in after her and both of them drowned. It’s those kinds of things tht you need to stay away.”
The Army Corp of Engineers sets guidelines for the water levels in the reservoirs. He says the water managers want to fill them as much as they can for the summer so it can be doled out to users.
“And some have just topped off and then the influents have slowed down. And so, that’s the gig. And a year like this, and we’ve had delay, there’s uncertainty as to how much more, extra we’re going to have due to the delay. They still want to fill it up, but then they have to release water to keep it from going over the spill way. You really don’t want it to go over the spillway cause then they loose control”
McInerny says Summit County doesn’t have flooding issues currently but he’s is most concerned with Deer Creek in Wasatch County.
“In Wasatch County, what happens when the Provo runs big, the canals, they hope people will use that water on their fields to de-water the canals to make room for the water that’s coming down. Or you could have what’s happening on Cutter Lane. You know, it’s out of its banks. It’s out of the channel. It’s running on the fields. It’s running on the road. It can be touch and go and Deer Creek, I’m looking at pretty close.”
He says the fields in the Kamas Valley are saturated and a bump in temperature and sunshine will accelerate a faster snow melt. He says for farmers and ranchers the key is that the water doesn’t sit on the surface too long.
“And you have water that’s saturated fields above ground. That infiltrates and ends up in Rockport reservoir. An inch to an inch and a half will give you some really big flows. We’re melting at three inches of snow water equivalent per day, which is phenomenal.”
McInerny says there is no catastrophic flooding right now and they’ve briefed municipalities and public works people, so everyone knows the melt is coming.
“And, now it’s happening. But everybody is pretty well prepared. The thing we worry about is how hot is it going to get.”
Real time water level updates can be found on waterwatch.usgs.gov.