Flood water breaches city’s reservoirs
Despite the magnitude and the widespread flooding that occurred in Thornton last week, the city didn’t experience the amount of damage experienced in other cities.
“We do have some repairs to make but Thornton was fortunate,” said Brett Henry, Thornton’s street operations manager.
The biggest concern for the city is the breach of one of its 12 dams along the South Platte River, said Emily Hunt, the city’s water resources manager.
“We had flood water overtop five of (the berms) — with one of the five, we had a complete failure of the berm so there’s no separation between the reservoir and the river right now,” she said.
The city isolated the reservoirs, and because the city has multiple water resources the drinking water has not been compromised, Hunt said.
Repairing the breached berm will take six to 12 months and is the top priority for the city. It could take between 18 to 24 months to repair the erosion on the other berms.
The flooding in other parts of the city occurred from overflowing streams, backed up sewers and gutters and detention ponds at full capacity and overflowing
“Too much rain in such a short period of time left nowhere for the water to go,” Henry said.
Beginning as early as 1 a.m. Thursday, Sept. 12, through mid-day the next day, the city had approximately a dozen roads completely closed and another dozen with lane closures. Some of those full closures included York Street between E470 and 156th Avenue, 144th Avenue from Washington to York streets, McKay Road from 104th to 96th avenues and southbound Colorado Boulevard from 104th to 102nd avenues.
The city had to re-close most of the full closures again on Sunday because of the afternoon rainstorms.
The city did lose the pedestrian bridge over Grange Hall Creek, and experienced erosion in multiple areas — including losing a portion of the shoulder on 128th Avenue west of Riverdale Road, which exposed a gas line, sewer manhole and a communications conduit — but no roads were lost, he said.
“All our dirt roads in the northeast section need to be re-graded because of potholes,” Henry said. “They’re passable, but not pleasant.”
He said after city workers tackle the larger issues of erosion, they will next evaluate the city-maintained detention ponds, drainageways and problem area storm sewers to determine what additional repair is necessary.
“In many cases this will just involve removing debris such as sediment, sticks, mulch, etc. from the detention ponds and storm sewer system to make sure it can operate at full capacity during the next storm event,” Henry said.
Rich Neumann, communications manager with Adams County, said he is unaware of any unaccounted for people in the county and doesn’t know how much structural damage has been done.
“At this point we do not know all of the specifics, but we assume most personal property damage will result from flooded basements. Some agriculture damage is also possible (i.e. crop damage),” he said. “To this point we’ve been focused on keeping citizens safe.”
Several roads in Adams County were closed on Sept. 12-15 at one point or another because of the flooding, including 128th Avenue at Riverdale, 124th Avenue between Riverdale and Old Brighton Road, Highway 76 at 88th in the eastbound lane, Riverdale between Colorado and 104th and Riverdale between McKay and 112th Avenue.
“Most roads that were unpassable remained closed for anywhere between 24 and 72 hours,” Neumann said. “The flooding was the result of saturated soils that could no longer absorb water, which led to massive demands on infrastructure and streams.”
However, despite the road closures, he said not much damage was reported for roadways or bridges.
The Adams County Animal Shelter Adoption Center and the Adams County Regional Park took in displaced animals from evacuees in the Irondale area of Commerce City.
“If we can ease the mind of evacuees even a little bit by providing a temporary, caring home for their animals, then we are doing our job of showing our concern for and commitment to our community,” said Adams County Board of Commissioners Chair Eva J. Henry in a statement.