Bullhead City moves to bank treated effluent as Lake Mead water reserve
Bullhead City, Arizona · Meeting date: November 3, 2026 · Published: November 4, 2026
Bullhead City Council has unanimously approved the local conservation exhibit for incorporation into a System Conservation Implementation Agreement with the US Bureau of Reclamation. The arrangement would allow the city to receive Colorado River conservation credits for returning A+ treated effluent from its Section 10 wastewater treatment plant to the river system.
Key points
- Council approved the Extraordinary Conservation – Intentionally Created Surplus exhibit by a 6-0 vote.
- Bullhead City expects to return roughly 3,700 acre-feet/year from its Section 10 plant, while the proposed agreement would allow credits for up to 5,000 acre-feet/year over 10 years.
- The city said it could accumulate 6,000-10,000 acre-feet of stored water over two years, depending on return flows.
- Credits would be held behind Hoover Dam in Lake Mead and could be used as makeup water if Bullhead City faces future reductions in its Colorado River supply.
- Staff said banking effluent would offer citywide flexibility compared with direct reclaimed-water use at facilities served by existing effluent pipelines.
Full report
Bullhead City is advancing a wastewater-to-water-supply strategy that could create a Lake Mead reserve for the Arizona municipality as Colorado River reductions remain a central concern across the basin.
The City Council voted 6-0 on 3 November to approve the City of Bullhead City Extraordinary Conservation – Intentionally Created Surplus exhibit for inclusion in a System Conservation Implementation Agreement being developed with the US Bureau of Reclamation.
The proposed arrangement centres on treated effluent from the city’s Section 10 wastewater treatment plant. Utilities Director Mark Clark told council that the plant historically sent all of its effluent to evaporation ponds, meaning it did not return to the Colorado River as system return flow. Under the proposed conservation mechanism, the city would send A+-class treated effluent into the Colorado River through subflow at the Section 10 facility.
Because the water had previously been lost to evaporation rather than returned to the river, Clark said the Bureau of Reclamation had identified the new return flow as a basis for creating Intentionally Created Surplus, or ICS. A downstream user, probably the Central Arizona Project, would take the water, while the Bureau would reduce that user’s order by an equivalent amount and retain the volume behind Hoover Dam in Lake Mead as Bullhead City’s credit.
"This is a way for us to actually get credit and have a savings account of water," Clark said. He said that local aquifer injection would not provide the same benefit because injected water migrates back to the river and the city would not receive credit for it.
The agreement would permit Bullhead City to create credits for up to 5,000 acre-feet/year over a 10-year term. The city cannot currently meet that ceiling: Section 10 produces about 3,700 acre-feet/year, while its Section 18 plant is not eligible at present. Clark said the higher contractual cap was intended to accommodate future growth without repeatedly seeking amendments, and to secure Bullhead City’s share of Arizona’s statewide 125,000 acre-feet/year ICS limit.
At current volumes, the city expects to bank about 3,700 acre-feet annually. Clark said stored volumes could total 6,000-10,000 acre-feet over two years and be used as makeup water if the city’s wet-water allocation is reduced in the future.
The strategy also changes the preferred use of Bullhead City’s reclaimed water. Clark said the city had previously considered using effluent at Chaparral Golf Course, Rotary Park and Palo Verde Meadows. Banking it as ICS would instead allow the city to use resulting water credits anywhere in the municipal system rather than only at locations reached by effluent pipelines.
The agreement is one of about six makeup-water programmes the city is pursuing, according to Clark. During the same meeting, he said Bullhead City was not expecting a reduction in wet-water use for the following year, subject to California joining a three-state Colorado River deal already signed by Arizona and Nevada.
This summary was generated by AI based on the source document and may contain errors.
Source: Regular City Council Meeting - Nov 03, 2026, Bullhead City