Reno Watering Rules: The TMWA 3-Day Schedule Explained

Under TMWA (Truckee Meadows Water Authority) rules, Reno and Sparks residential customers are allowed to run irrigation 3 days per week — never on back-to-back days. Watering is restricted to before 11am or after 7pm every day, regardless of your assigned days. That 8-hour midday blackout applies year-round, even in peak summer heat.

Your assigned days depend on your address. Odd-numbered addresses water on Sunday, Tuesday, and Thursday. Even-numbered addresses water on Monday, Wednesday, and Saturday. Friday is off-limits for both groups. The rule exists to spread demand on the regional water supply, which draws heavily from the Truckee River. During drought declarations, TMWA can tighten restrictions further, so it pays to check their website or call before assuming your schedule has not changed.

Running sprinklers during the midday window is not just against the rules — it is also hard on your lawn. At Reno's elevation of roughly 4,400 feet, summer temperatures routinely hit the 90s. When you water mid-afternoon, a large share of that moisture evaporates before it ever reaches the root zone. You end up using more water for less result.

Early morning is the most efficient window for Reno yards. Temperatures are lower, wind is usually calm, and the grass has time to dry before evening, which reduces fungal pressure. If your controller is set to run at 6am on your allowed days, you are already doing better than most.

If you are not sure when your system actually runs, a quick walk around the yard while the zones are active tells you a lot. Look for heads that are not popping up fully, arcs that fall short, or runoff pooling on hard surfaces — those are signs the schedule or the hardware needs attention.

Most Reno yards sit on clay or caliche soil. Both drain slowly. When irrigation runs too long on a single zone, water piles up faster than the soil can absorb it and runs off the property instead of soaking in. You are wasting water and potentially violating the spirit of the restrictions — all while underwatering your grass.

The fix is cycle-and-soak: instead of running a zone for 12 straight minutes, split it into two 6-minute runs with a 30–45-minute gap in between. Most modern irrigation controllers have a cycle-and-soak setting built in. If yours does not, you can approximate it by running two separate start times on the same day. This approach lets the water percolate between cycles and dramatically cuts runoff.

TMWA's 3-day limit also means your controller runtime per zone matters more than it does in wetter climates. Getting the math right — turf type, sun exposure, slope, nozzle output, and soil absorption — is what separates a healthy lawn from a stressed or overwatered one.

A common mistake is setting one runtime across the whole yard. Reno properties almost always have mixed conditions: a south-facing slope that dries out fast, a shaded side yard that stays damp, a strip along the street that gets extra reflected heat. Each zone ideally has its own runtime.

For cool-season grasses (fescue, bluegrass) common in Reno, a reasonable starting point in July and August is roughly 1 to 1.5 inches of water per week across your 3 allowed days. Most residential rotary heads put out about 0.4 to 0.5 inches per hour; spray heads put out more. If you do not know your head output, TMWA publishes a catch-cup test guide on their website that walks you through it in about 20 minutes.

Once water savings season ends and temperatures drop — typically by mid-September in the Truckee Meadows — start stepping runtimes down. By mid-October, most Reno lawns need little to no supplemental water. That is also when you should be thinking about irrigation winterization, which protects your backflow preventer and poly lines from freeze damage.

TMWA can issue warnings and fines for schedule violations. The most common ones we see in Reno neighborhoods are watering on the wrong day, controllers that did not get updated after daylight saving time, and systems running during the midday blackout because a program was inadvertently set to a 12pm start instead of 12am.

A few things worth checking right now: confirm your controller's clock is accurate, verify you are not running any program with a start time between 11am and 7pm, and make sure your day assignments match your actual address parity. If you have a smart controller that pulls weather data, double-check that its automatic schedules also respect the TMWA day restrictions — some smart systems optimize for ET (evapotranspiration) without accounting for local water authority rules.

If a zone is running outside your window, it is usually a rogue program, a stuck valve, or a failed controller module. These are fixable problems that do not require replacing the system.

If your lawn is stressed despite following the TMWA schedule, the problem is usually the system, not the rules. Worn nozzles lose their arc and output rating. Heads settle or get bumped out of alignment. Valves stick open or fail to open. Backflow preventers drip. Any of these issues means your grass is getting uneven water even if the controller is programmed correctly.

ShieldMePM handles irrigation service and repair in Reno and Sparks — including spring start-ups at $99 and fall winterization blowouts at $110. A start-up visit includes a full zone-by-zone check: we inspect heads, test run times, flag anything that looks worn, and confirm the schedule is set up within TMWA's restrictions. Winterization drains and blows out your lines before the first hard freeze, which typically arrives in Reno between late October and mid-November.

If you are on one of our Complete or Premier lawn care memberships, irrigation checks are part of your seasonal routine. You do not have to remember to call — we flag issues when we are already on-site.

Odd addresses (water Sunday, Tuesday, Thursday). Even addresses (water Monday, Wednesday, Saturday). No watering Friday for either group. No watering between 11am and 7pm, any day. Maximum 3 days per week, never consecutive. Restrictions apply year-round, with potential tightening during drought declarations.

For the most current information, visit tmwa.com or call TMWA directly. Rules can be updated seasonally, especially during drought years. If you want help dialing in your system to work efficiently within those rules, ShieldMePM is at (775) 200-9710 or shieldmepm.com.