Outdoor Watering in Missoula: Guidelines and Conservation

What are Missoula's recommended watering hours?

The City of Missoula's conservation page says that from May 1 to September 30, recommended watering hours are 6 to 11 a.m. and 5 to 10 p.m. The same page advises watering lawns only when needed and during cooler parts of the day. Those windows line up with what Montana State University Extension recommends: its Yard and Garden Water Management MontGuide says lawns watered under the hot midday sun can lose as much as 30 percent of applied water to evaporation, and that early morning and early evening are best.

MSU also cautions against watering late in the evening, because plants that stay wet and cold all night can develop fungus. For an automatic system, that makes the early part of the morning window the best default and the evening window a fallback.

Does Missoula have odd-even or day-of-week watering rules?

Not on the city's conservation page when we checked it in November 2026. The page gives recommended hours, not a mandatory schedule, and does not mention odd-even days, rebates or restrictions. That can change in a drought year, so check the city's Missoula Water pages each spring, and ask Missoula Water directly if you see a restriction reported elsewhere. Our older post on water-wise irrigation windows in Missoula covers why the timing matters.

Where does Missoula's water come from?

The aquifer. The city's Missoula Water page says the utility provides drinking water, irrigation and fire protection, and describes the Missoula Valley Aquifer under the city as one of the finest sources of groundwater in America, but notes that in some places it is no deeper than 40 feet below the surface, which makes it very susceptible to contamination. The conservation page calls the aquifer a finite resource that everyone depending on it benefits from conserving.

That shallow aquifer is also why backflow protection matters so much in Missoula. Lawn sprinkler systems sit in fertilized soil, and Missoula Water requires approved backflow preventers on all underground irrigation systems, tested annually. Our backflow testing guide covers the program.

What conservation tips does the city give?

The city's outdoor list is short and practical: deep-soak lawns to encourage healthy root growth; check hoses, pipes, faucets and connections for leaks; choose climate-adapted, water-efficient landscaping; mulch around trees and plants to keep moisture in the soil; sweep sidewalks, driveways and steps instead of hosing them; shut off the hose while washing the car; and adjust sprinklers so water does not land on sidewalks and streets. The page's water consumption chart lists an average hose at about 10 gallons a minute, which is a useful reminder of how quickly an unattended hose adds up.

How much water does a Missoula lawn need?

Less often, more deeply, is the consistent advice. MSU's MontGuide says established lawns need only 1 to 2 inches of water every 3 to 5 days, about an inch every 3 days in very hot weather, and that one deep watering to fill the root zone is much better than several light ones, because frequent shallow watering produces shallow roots. EPA WaterSense's watering tips say landscapes typically need about an inch of water a week including rainfall, varying with weather and plants, and suggest timing how long your sprinklers take to fill tuna cans with half an inch of water.

Those two sources describe different conditions (MSU's figure is for heat, EPA's is a general average), which is exactly why a fixed schedule does not work all season. Our summer watering guide goes deeper on lawns, and our guide to drought-dormant lawns covers letting grass rest in a dry spell.

How do you know how much your system puts down?

Measure it. MSU's MontGuide describes a can test: set 3 to 5 straight-sided cans in a line across a sprinkler's pattern, run it for half an hour, add the depths, divide by the number of cans and multiply by 2 to get inches per hour. MSU also suggests checking depth with a metal rod or a spade after watering. Once you know the rate, you can set run times to hit the target depth within the city's watering windows, split into shorter cycles if water starts to run off.

Does metered billing change how you should water?

It makes your watering visible. The Missoula Water page explains that most homes are on metered service, billed a fixed rate by meter size plus usage, and that conservation shows up as savings. Older flat-rate accounts are billed by rooms and fixtures, with a separate flat sprinkling charge based on yard square footage, and no new flat-rate customers are being signed up. The city also says that under Missoula Municipal Code section 13.30.580, a flat-rate property must convert to metered service before it can be sold or transferred, with the meter installed at no cost unless plumbing changes are needed.

The city's newer AMI meters transmit readings every 15 minutes, and the city says customers will be able to see daily and hourly use and set alerts for continuous flow, which often indicates a leak. For anyone with an irrigation system, that alert is worth turning on; our irrigation leak signs guide explains what to do when it fires.

What system changes save the most water in Missoula?

Fixing what wastes water first, then adding control. EPA's Sprinkler Spruce-Up lists the order: inspect for broken and tilted heads, check connections and valves for leaks, direct heads for head-to-head coverage and away from pavement, and choose a WaterSense labeled controller. EPA estimates a labeled weather-based controller can save an average home nearly 7,600 gallons a year compared with a clock timer. Our guides to smart irrigation controllers and sprinkler head types cover the hardware, and our drip irrigation guide covers moving beds off spray heads.

Planting changes help too. The city's tip about climate-adapted landscaping is the idea behind xeriscaping in western Montana and replacing lawn with native plants.

What should a new Missoula homeowner check?

A few things in the first season save trouble later. Confirm that the property is on metered service; the city says flat-rate properties must convert before a sale, so most recently sold homes will be metered, but older accounts may not be. Find the backflow preventer and ask Missoula Water whether it is on file and when its last test was, since the utility requires annual testing on underground irrigation systems and sends notices when one is due. Sign up for the meter portal and its continuous-flow alert when it is offered to you.

Then look at the system itself. Run each zone and note what it waters, whether any heads spray the sidewalk or street (the city specifically asks owners to adjust them), and whether beds are on spray heads that could move to drip. Set the controller to run inside the 6 to 11 a.m. window, and make a note of the date to schedule a fall sprinkler blowout, because Missoula's first hard freeze rarely waits for a convenient weekend.

Do these guidelines apply outside the city?

No. They are Missoula Water's recommendations for its customers. Properties in Lolo, Clinton, the Bitterroot towns or rural Missoula County may be on another water system, a private well or a ditch, each with its own rules. Our guides to irrigating from a well and Bitterroot ditches and water rights cover those situations.

Can HJ set up a system to follow the city's guidance?

Yes. We program controllers to run inside the recommended windows, split runs into cycle-and-soak where soils or slopes need it, fix heads that spray pavement, and add drip and smart controls where they pay off. This guide is part of our Montana Landscaping, Lawn & Irrigation Guide, and our irrigation systems page explains how we work. Call HJ Property Care & Tree Service at (406) 215-7319 or request a free estimate. We work across Missoula and Ravalli counties, from Missoula and Lolo to Florence, Stevensville, Corvallis, Victor, Hamilton and Darby.

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