When interim City Manager Sara Ott lies awake at night thinking about work, she has water on her mind.
In a presentation to members of the Aspen Chamber Resort Association on Tuesday morning, she said Aspen’s water supply is one emergency away from being unavailable.
Ott said Leonard Thomas Reservoir, which feeds the city’s water treatment plant, holds enough water for the community for about half a day.
“My experience tells me that that is nowhere near enough,” she said.
The city primarily gets its water from Castle and Maroon creeks. Last month, avalanches and debris in the watershed threatened water flow upstream of city intake pipes in both valleys.
“Thankfully we avoided a pretty significant threat to our water system,” Ott said.
Margaret Medellin, the city’s utilities portfolio manager, spoke later on Tuesday about how the city is extremely dependent upon water flowing freely through the head gates at Maroon and Castle creeks to maintain its water supply.
She said the city was closely monitoring water flow levels days before the March 9 avalanche in the Castle Creek Valley and was able to act quickly when the debris came through.
“We were as prepared as we could be,” she said.
City staff maintains the head gates daily, chipping out ice, moving tree branches and boulders and then mitigating sediment blockage during runoff season. During the early March event, they were on the scene right away and the water was able to make its way through the deluge.
“From my perspective as a water manager, we need to plan a little more resilience in our system so if something did happen that we couldn’t clear things within a day, we’d have a little more storage to live on,” Medellin said.
Along with natural causes such as headwater blockage, Medellin said Aspen is vulnerable in other ways. Last year, the Lake Christine Fire on Basalt Mountain threatened power in the upper valley. If the power lines had failed, the pump stations that get water to users would have been affected.
Medellin said she tries to plan for what the water manager of 2060 will be dealing with, but there is always the unknown. A car crash in Maroon Creek last fall was close to the head gate and could have compromised water quality.
“You think you’ve planned for it all and then you get a flying Tesla at your head gate,” she said.
Last year, the city settled a long battle in water court with residents and environmental groups opposed to creating water storage in the Maroon and Castle creek valleys. Critics say the city’s claims about the need for water storage are exaggerated.
Medellin said the greatest vulnerability to the local water supply is climate change. Historically, demand for water and availability have mirrored each other, but in low snow years or years with early runoff, that could change. And once Aspen runs out of water, there isn’t an easy way to call for backup.
“We are uniquely vulnerable not only because we have such a limited amount of storage but we are also at the top of the watershed. We don’t really have the ability to tap into a neighbor system if we get into trouble,” Medellin said.
Aspen is still currently under Stage Two water restrictions due to last year’s low precipitation. Those restrictions will be discussed in May at the city council level following updates from state drought officials.
Speaking to the business community Tuesday morning, Ott emphasized the need to continue to explore Aspen’s water options.
“The notion of only storing our water supply in snow really doesn’t address our true needs,” she said. “I encourage you to not let this fall off your radar screen.”