From The Glenwood Springs Post-Independent (Ike Fredregill):
Glenwood Springs mayor, staff express confidence in $3.2 million water system investment in wake of 2020’s Grizzly Creek Fire
Recent upgrades to Glenwood Springs’ water infrastructure likely prevented a July 31 and Aug. 1 deluge from overcoming the city’s water filtration system, Glenwood Springs Public Works director said.
The record-breaking rainfall, which dumped up to 2 inches of precipitation in an hour near Coffee Pot Road and caused severe mudslides, pushed a significant amount of sediment-laden water toward the city’s water intakes at Grizzly Creek/No Name Creek and Roaring Fork River within a matter of hours.
“The water we had simply wasn’t usable at that point,” Public Works Director Matt Langhorst said, explaining the water’s turbidity levels during the storms shot up to 4,000 Nephelometric Turbidity Units, a measurement of water cloudiness.
The city’s intakes typically experience a turbidity level of about 4-7 NTU in a system that treats about 4.5 million to 4.7 million gallons of water daily during the summer. It might have taken days to drain the storm-induced sediment out of the city’s settling tanks without the city’s $3.2 million infrastructure upgrade, Langhorst said…
Below is a look at the city’s upgrades at work during the storms:
• Bank armoring at the No Name and Grizzly Creek intakes stabilized the earth around the intakes during the heavy rain and mud events.
• The automated gate at No Name Tunnel quickly gauged elevated levels of sediment in the intake and closed off the pipeline to the water treatment plant, preventing water lines from becoming inundated with mud.
• The treatment plant’s stainless steel settling plates, which replaced plastic settling plates, increased the settling area square-footage by 28%, allowing the new sediment pumps to push sediment out of the water system at a much faster rate, according to Glenwood Springs spokesperson Bryana Starbuck and Water Treatment Plant Chief Operator Mike Hedrick.