Boulder City Council unanimously voted last week to move forward with a temporary ban on graywater reuse systems, setting the ordinance to last two years. Common water conservation habits, such as collecting water from a warming shower to water plants, will not be affected. The ordinance passed with limited public engagement and lingering concerns from residents.
Graywater refers to slightly used water — such as from bathroom sinks, showers and washing machines — that can be reused for flushing toilets or underground irrigation. A separate plumbing system must be installed to capture and treat graywater for reuse before it enters the sewer.
A state law passed in 2024 will automatically allow graywater reuse in new construction beginning Jan. 1, 2026, unless municipalities choose to opt out. Boulder currently does not permit graywater reuse systems. City staff estimated it would take at least two years to create the necessary programs, infrastructure and enforcement mechanisms for a graywater system, making implementation before the state’s deadline infeasible.
Other reasons cited by staff for recommending the ban included low participation in communities that do allow graywater and the results of a local pilot program at CU Boulder’s Williams Village, where graywater saved less water than anticipated and proved expensive to maintain. Staff acknowledged that graywater reuse is a tangible method of water conservation and expressed openness to revisiting the issue in the future. However, they emphasized urgency in passing the ordinance to comply with state law.
The ordinance was approved with little public discussion. For the Planning Board, it appeared only as an informational item, and board members were not able to ask questions due to a meeting power outage. The issue was presented to the Water Resources Advisory Board in September, which voted to recommend the ordinance. Graywater appeared on city council’s consent agenda for both the first and second readings. At the second reading, council added the two-year limit to give staff time to prepare programs if the city later decides to allow graywater reuse.
Planning Board Chair Mark McIntyre, speaking in his personal capacity, said the ordinance runs counter to Boulder’s sustainability goals and that the state legislation was intended to encourage, not restrict, graywater use. McIntyre also said city staff told him the ordinance would rely on selective, complaint-based enforcement.
“Writing and enshrining code that requires selective enforcement and can be used as a malicious tool by complaint-based enforcement is bad lawmaking,” he wrote in a memo to city council.
McIntyre said he wants to see clearer details and definitions in the ordinance outlining exceptions and prohibitions. He also called for broader public engagement on graywater, including conversations with urban agriculturalists.
“Once this engagement is complete, then I think drafting a fair, thoughtful, and effective ordinance will be much easier,” said McIntyre in the memo.
Ordinance 8720 will take effect Jan. 1, 2026, and expire Dec. 31, 2027.
This is disappointing. We need to develop innovative systems for the Water, Environment, our climate, waste, and resilience. Graywater use is one way. Boulder always claims leadership and innovation for sustainability which makes this decision even more frustrating than it already is.
The systems, policies, and regulations in place give us the unjust, wasteful, environmentally catastrophic outcomes we have now. We need deep changes if we want different outcomes. Policy-makers must find better solutions or turn to others for help rather than make conciliatory policies like this. I understand they feel stuck. But I’ve heard a call from both council and the community to be more bold. We need that bold innovation with water conservation and graywater. That should be just the tip of the iceberg.
I second Michelle.