NOVEMBER WATER QUALITY SUMMARY:

November 18, 2025

Phosphorus binding treatment curtailed by weather. City staff and consultants applied most of the granules. The remainder will be applied in early December.

November 17, 2025

The City will be applying a phosphorus binding treatment to the lake sediment for approximately 4 days.

All normal lake uses will be available during the treatment.

This treatment will focus on binding the phosphorus found in the lake bottom. This will greatly improve the water clarity in the lake, reduce the volume of sediment and also help prevent the extensive aquatic weed and algae blooms we usually experience in the spring. This treatment is certified aquatic life and drinking water safe.

OCTOBER 2025 WATER QUALITY SUMMARY:

Watson Lake is now in its winter mode, the top and bottom waters of the lake have mixed. During summer, the lake is stratified into a warm top and cold bottom. The City expects no issues with algae, aquatic weeds, or water quality until late spring when the lake stratifies again for summer. Please see the diagram below for more info:

SEPTEMBER 2025 WATER QUALITY SUMMARY:

Watson Lake water depth as measured in summer 2025

AUGUST 2025 WATER QUALITY DATA SUMMARY:

JULY 2025 WATER QUALITY DATA SUMMARY:

June Treatment Update: Public Works and their lake management consultant performed the first ever phosphorus binding treatment of Watson Lake to remove over 220lbs of phosphorus from the water. As a result, there have been no algae blooms this summer at Watson Lake.

OCTOBER 2025 WATER QUALITY SUMMARY:

September 24, 2025

Willow Lake is currently 15+ feet below the spillway due to poor rainfall and an ongoing sewer infrastructure project. The remaining small pool of water is difficult to access and has deteriorating water quality. Other area lakes are recommended for paddling and fishing.

August 14, 2025 photos while water quality monitoring

AUGUST 2025 WATER QUALITY SUMMARY DATA:

WATER LEVEL UPDATE:

Willow Lake water levels are currently low due to ongoing infrastructure work coupled with below average precipitation for 2025. The lake is expected to naturally refill in 2027. For water-based recreation you may wish to visit another lake until conditions normalize.

NOVEMBER 2025 WATER QUALITY SUMMARY:

OCTOBER 2025 WATER QUALITY SUMMARY:

SEPTEMBER 2025 WATER QUALITY SUMMARY:

September Treatment Update: In response to increasing algae due to high nutrient levels public works applied phosphorus binder to Upper Goldwater Lake. No use restriction is in place and the lake remains open as usual.

August Ammonia Testing: Seeing a rise in ammonia but still within AZ surface water quality limits.

AUGUST 2025 WATER QUALITY DATA SUMMARY:

JULY 2025 WATER QUALITY DATA SUMMARY:

TREATMENT UPDATE:

Monthly treatments of Upper Goldwater Lake will continue through summer to reduce organics and phosphorus in order to improve water quality and lake ecosystem health.

NOVEMBER 2025 WATER QUALITY SUMMARY:

OCTOBER 2025 WATER QUALITY SUMMARY:

SEPTEMBER 2025 WATER QUALITY SUMMARY:

AUGUST 2025 WATER QUALITY DATA SUMMARY:

JULY 2025 WATER QUALITY DATA SUMMARY:

Area Creeks:

Aspen, Banning, Bottleneck Wash, Butte, Government Canyon, Granite, Manzanita, Miller, North Fork Granite, North Fork Miller, Slaughterhouse Gulch, Virginia Street Wash, Willow, Yavapai College Wash

BOLD indicates the creek has an E. coli impairment.

Stagnant and/or muddy water can be an indicator or elevated E. coli levels.

SEPTEMBER 2025 WATER QUALITY DATA SUMMARY:

Storm drain outfall E. coli sampling.

This is done to measure pollutants as they leave City streets and stormdrains but before they reach local creeks.

Images from September creek monitoring and sample analysis:

AUGUST 2025 WATER QUALITY DATA SUMMARY:

Storm drain outfall E, coli sampling