Drip System Irrigation
In Xeriscape Garden Design
State of Texas Licensed Irrigator # 6207
Water usage is one of the most critical issues facing Texas, both now and into the future. The solutions we find will have a huge impact on our environment and our quality of life – not to mention our bank accounts. This urgent issue can only be addressed if we have a clear understanding of how we now use water and how we can be more efficient going forward, and outdoor watering is one major area of water use in Texas that needs to be changed, especially through the dreadful heat of summer when water usage skyrockets.
The National Wildlife Federation and the Lone Star Chapter of the Sierra Club have reviewed outdoor water use in Texas cities in recent years to create a better understanding of outdoor water use in our state and to examine how we might become more efficient in that use. In the 18 cities they examined total water use increased by 58% in July through September compared to the winter usage December through February. The vast majority of the 13.5 billion gallons of water goes onto landscapes and much of that either runs off or evaporates into the hot air before it has a chance to sink into the ground. It has been estimated by the Texas Water development Board that around 50% of this precious water is wasted.
Their analysis estimates how much water each city could save, on average, every day during the summer with just a 25% reduction in outdoor water use. This level of reduction has been proven to be realistic and achievable. In Austin’s case this would equate to about 13,900,000 gallons. Every day!
The best way to achieve a more efficient use of water in the landscape is a Drip System.
The idea is not to deliver less water to the plant. It needs to receive the same amount of water for ideal health, no matter what method you use. The difference with a drip system is the idea of targetted irrigation. The emitters are closer to the plant material than pop-up sprinkler heads would be and so the delivery is more efficient. It is also slower, allowing a deep watering of the plant root system. Drip system emitters typically put out around 1 gallon per hour, whereas a pop-up sprinkler head averages about 2 gallons per minute.
The drip system line is placed under a good 3-4 inches of mulch the evaporation rate is virtually zero. Compare that to a traditional lawn sprinkler that can lose up to 90% (depending on air temperature, humidity and wind speed) of the water to the atmosphere before it can soak into the ground!
A blanket coverage is not the only way to go when installing a drip system. Instead of having emitters spaced at a standard 12 inches, customize the system to emit water only around the root zones of individual plants. In a minimal landscape the savings can be considerable, such as here