Water conservation ‘critical’ for Aspen amid concerns with Castle, Maroon creeks runoff

Water conservation is “critical” in Aspen as Castle and Maroon creeks runoff season begins, according to the city’s Director of Utilities Erin Loughlin Molliconi.

Aspen is currently in a stage two drought declaration, in effect since Sept. 1, with the warmest winter on record in Colorado in the past 131 years and snowpack levels below normal, according to Loughlin Molliconi.

“We are certainly entering a time which is unprecedented in the lack of snowpack and projected temperatures and precipitation, even to our most tenured staff,” Loughlin Molliconi said. “Our operators are ready and prepared to continue treating the raw water, which comes in from Castle and Maroon creeks to meet system demands for municipal uses. We are concerned about the possibility of making operational decisions, which will impact ecosystems or other priorities of the community and city.”

Those operational decisions could include turning off Maroon Creek hydroelectric facility or pulling water through the headgates and making it so that Castle and/or Maroon creeks fall below the minimum in stream flow targets that the city aims to meet — that would mean compromising stream and aquatic life in order to continue meeting municipal demands. 

“We hope this won’t be the case, but we are particularly concerned about facing that situation if some customers are not doing their part to conserve, particularly regarding outdoor irrigation,” Loughlin Molliconi said.

She pointed out that snowpack typically peaks in April — instead, Colorado’s snowpack as a whole has been taking a nosedive leading into the month. The city “relies heavily” on the seasonal runoff of Castle and Maroon creeks for drinking water, she added, which historically sees “a significant increase” once the snowpack starts to melt.

“The city’s water treatment system relies upon the stream flows in Castle and Maroon creeks; so any significant reduction in the snowpack and associated runoff would have an effect on the availability of the run-of-the-river supplies,” she said. “Ultimately, our snowpack and the water that results from its runoff is Aspen’s water storage.”

The run-of-the-river has only eight to 12 hours of storage during peak summer demand, according to Loughlin Molliconi, which refers to the raw water storage in the Leonard Thomas Reservoir. That reservoir receives the flows piped from the headgates on Castle and Maroon creeks, prior to treatment for potable consumption, and can hold approximately 3 million gallons of water, she confirmed. Treatment staff monitor system demands and water quality constituents — like turbidity — in order to optimize reservoir levels.

During historic peak usage, the volume in that reservoir will “turn over” between two to three times in a day, she shared, which correlates roughly with the eight to 12 hours of storage.  

“The city does not have separate sources,” she added. “Redundancy of our source waters comes from our separate intakes in the Castle Valley and Maroon creek valleys. This is one of the main drivers behind the need for conservation we would like to communicate to the community. It is critical for water customers to collectively respond to drought measures so that conservation habits become routine.”

Loughlin Molliconi stressed this is particularly critical in the event of an emergency — where source water supply would be limited and the water utility would need all customers to “very quickly reduce their consumption in order to continue meeting system demands and priorities.” 

Water conservation measures get enacted with the aim of preserving the limited water supply in order to continue meeting “the most highly-prioritized uses for health and safety,” according to a letter she wrote for the city. This includes drinking water, sanitation, pressure and storage for structural firefighting, the protection of the natural environment and recreation in public spaces.

“We need the whole community — from full-time residents to tourists coming in for a weekend — to help conserve and protect our finite water resources,” she wrote.

The city offers a number of programs to help contribute to the water conservation cause, including:

• Free irrigation efficiency assessments  
  • Residents are able to schedule a free irrigation efficiency assessment, where a certified professional evaluates the irrigation system, checks each watering zone and recommends upgrades to save water and money.
  • The city offers a 50% rebate (up to $2,500) for recommended efficiency improvements.
  • For more information, visit aspen.gov/1536/Irrigation-Assessment-and-Rebates.
• Commercial Water Efficiency Challenge   
  • Local businesses can participate in the Commercial Water Efficiency Challenge, earning points for conservation actions and qualifying for rebates up to $7,500 to upgrade water-using equipment.
  • For more information, visit aspen.gov/1746/Commercial-Water-Efficiency-Challenge.
• Qualified Water Efficient Landscaper Program   
  • The  QWEL certification program is heavily subsidized by the city and trains irrigation and landscape professionals to design and maintain systems that conserve water, with participants learning about irrigation scheduling, plant types, soil conditions and system design.
  • Since 2018, Aspen has certified more than 100 local professionals through this program.
  • The city hosts the three-day QWEL training course each September.
  • Certified professionals also conduct the third-party irrigation audits required for WELS inspections. 
  • For more information, visit aspen.gov/1195/Qualified-Water-Efficient-Landscaper-Pro.
• Water Efficient Landscaping Standards
  • Aspen’s Water Efficient Landscaping Standards promote healthy landscapes while reducing water waste, as required by the city’s land use code. The program sets a maximum water budget of 7.5 gallons per square foot per season — about half the water typically used by traditional lawns.   
  • Since 2018, the city has approved more than 320 WELS reviews, with over 100 properties completing final inspections. 
  • For more information, visit aspen.gov/199/WELS—Water-Efficient-Landscaping-Stand.

“We know that raw water storage is a big resilience gap in our municipal portfolio,” Loughlin Molliconi noted. “The city continues to pursue the water rights diligence case for the conditional water storage rights for Castle and Maroon creeks, which we hope to successfully identify changed storage locations so more detailed design and planning can be pursued to bring that long-term strategic plan to fruition.”

The team is also continuing to look at other resources in its portfolio, along with the feasibility to increase the municipal supply in the future.