Outside Water Conservation Tips


Choose the right plants for this area. Native and drought-tolerant plants require much less water than other plants. And they are more likely to be resistant to pests and diseases. Check out the following for more information on native and drought-tolerant plants for this area:

Watering Plants

Not sure how much water your plants need? Ask ET! ET stands for evapotranspiration and is a measure of how much water is lost from the soil through evaporation and from plants through transpiration. You can figure out how much water your plants need by looking at how much water was lost through ET. For more information on using ET go to the Texas ET Network website.


Use mulch in beds and around trees. Mulch reduces evaporation of water from the soil and keeps the soil cooler. It also limits weed growth. You should maintain a depth of three to four inches around trees and in beds. Do not mound or pile mulch around tree trunks.

When to Water

Water in the morning or evening when evaporation rates are lower. If you water during the day almost half of the water will evaporate before it gets to your plant's root system. City code prohibits use of sprinklers between 10 a.m. and 8 p.m.

Wait a week between waterings. This will encourage your plants to develop deep root systems and make them more tolerant to droughts.


Use efficient irrigation methods such as surface or sub-surface drip. Drip irrigation applies water directly to the root system where it is needed instead of spraying it into the air where much of it will be lost to wind drift and evaporation.

Maintain your irrigation system. Make sure to check your system regularly for broken or clogged heads, heads that are spraying over streets or driveways, and heads that are misting due to high pressure. And adjust your watering schedule at least every season.


Harvest rainwater and use it for irrigation. Rainwater is free and is exempt from drought regulations. And it is great for plants because it doesn't contain salts and minerals. The City offers a rebate for water customers that purchase rain barrels. For more information on rainwater harvesting:


Check into using greywater for irrigation. Greywater is drain water from bathtubs, showers, bathroom sinks, and clothes washers. It does not include water from toilets or kitchen sinks. Greywater use is permitted in San Marcos provided it does not create a nuisance or health hazards. Review the City's Greywater Ordinance (PDF) for more information.

Lawn Care

Leave your grass a little taller, and don't cut off more than 1/3 of its length at a time. Taller grass holds moisture better, but cutting too much off at once will stress your grass.

Leave grass clippings on the lawn, and use a mulching blade on your mower to shred leaves rather than raking and bagging them. Both break down quickly and provide valuable nutrients as they decompose.


Choose natural fertilizers like compost instead of chemical fertilizers. Chemical fertilizers are often over-applied and can be hard on your plants. They can also be washed off into our rivers and streams during rainfall events and cause water pollution.


Improve your soil. Core aeration of lawn areas loosens soil and allows air, water and nutrients into the root zone. Follow the aeration with a 1/4 to 1/2 inch top-dressing of high-quality compost to add nutrients to the soil and help it to retain water.

Pools / Water Features

If you have a swimming pool or hot tub, keep it covered when not in use to lessen evaporation. And backwash filters only when necessary.

Turn off decorative water features when it is windy or during drought to reduce evaporative losses.