Reno, Nevada is one of the fastest-growing cities in the American West, and it’s trying to grow in a place where water has never been abundant. The Truckee Meadows Water Authority (TMWA) serves about 430,000 people in the Reno-Sparks metro area, drawing primarily from the Truckee River (fed by Lake Tahoe and Sierra Nevada snowpack) and supplemented by groundwater wells.
The math is straightforward and uncomfortable: more people, the same river, and a warming climate that’s changing the snowpack patterns that feed it.
Drought and Supply Stress
The Truckee River’s flow depends almost entirely on Sierra Nevada snowpack. In good years, there’s plenty. In drought years — which have become more frequent and more severe — the river runs low and TMWA leans harder on groundwater to fill the gap.
The Truckee River Operating Agreement, a complex legal framework governing water rights among upstream and downstream users (including the Pyramid Lake Paiute Tribe and irrigation districts), constrains how much water Reno can take during low-flow periods. Climate projections suggest more precipitation will fall as rain rather than snow, leading to earlier runoff and less water stored in the snowpack for summer use.
TMWA has invested in aquifer storage and recovery (ASR) programs — essentially banking excess surface water underground during wet periods for retrieval during drought. It’s smart planning, but the volumes stored may not be enough to offset the worst-case scenarios.
Arsenic: A Natural Desert Problem
Arsenic in groundwater is common across Nevada’s Basin and Range geology. The mineral occurs naturally in volcanic rock formations that underlie much of the Truckee Meadows. Some TMWA groundwater wells produce water with arsenic levels that require blending or treatment to stay below the EPA’s 10 parts per billion MCL.
This isn’t industrial contamination — it’s geology. But geology doesn’t care about MCLs. For TMWA’s municipal customers, the utility manages arsenic through well selection and blending. Private well owners in Washoe County don’t have that luxury and should test their wells regularly.
Arsenic at levels near or above the MCL has been associated with increased cancer risk, cardiovascular effects, and developmental issues in children. Even levels below 10 ppb are being re-evaluated by researchers who argue the current standard isn’t protective enough.
PFAS Near Military Installations
The Reno-Tahoe International Airport shares facilities with the Nevada Air National Guard, and AFFF firefighting foam was used historically at both military and civilian aviation facilities. PFAS contamination has been detected in groundwater monitoring wells near the airport.
TMWA has been testing its production wells for PFAS compounds under the EPA’s UCMR 5 program. Results have generally been below the federal MCL of 4 ppt for PFOA and PFOS, but some detections have been reported. The utility is monitoring the situation closely as treatment may become necessary if contamination migrates.
Stead, a community north of Reno near the former Stead Air Force Base, has had more significant PFAS concerns in local groundwater. The Air Force has been conducting investigation and remediation at the former base.
Wildfire and Watershed Risk
Northern Nevada’s wildfire risk has increased dramatically. The 2023 and 2024 fire seasons brought large fires near Reno’s watershed, and post-fire erosion can dramatically affect source water quality. Burned watersheds shed sediment, nutrients, ash, and fire-mobilized contaminants into rivers and reservoirs during rain events.
TMWA has developed wildfire response plans for its treatment plants, but a major fire in the Truckee River watershed could cause significant short-term water quality challenges — turbidity spikes, increased organic matter, and elevated disinfection byproduct formation.
Water Hardness and Treatment
Reno’s water is moderately hard (100-200 mg/L as calcium carbonate depending on the source blend). TMWA uses chloramine for residual disinfection, which produces fewer disinfection byproducts than free chlorine but requires awareness from dialysis patients and aquarium owners.
The treatment approach varies by source. Surface water from the Truckee River gets full conventional treatment. Groundwater may only need disinfection and possibly arsenic management.
What Residents Can Do
- Conserve water. In a desert city, conservation isn’t optional — it’s how you keep the supply viable for everyone.
- Filter if concerned. Reverse osmosis handles arsenic, PFAS, and most other contaminants of concern in Reno’s water. Carbon filters handle chloramine and taste.
- Private well owners in Washoe County: Test for arsenic, nitrates, and bacteria annually. Add PFAS if near the airport or Stead.
- After wildfires: If you notice taste, odor, or color changes in your water, contact TMWA. They may be adjusting treatment in response to watershed conditions.
If you’re concerned about your water quality, a certified water treatment professional can test your water and advise on the right system for your home.
For more on arsenic in drinking water, see our coverage of Albuquerque water quality. Learn about choosing a water filter.
Sources: Truckee Meadows Water Authority, Nevada DEP, EPA SDWIS, USGS, Washoe County Health District