Here are some best use water conservation tips for your irrigation system:
- Check for and repair leaks.
- Maintain your sprinkler heads and valves.
- Avoid oscillating sprinklers and sprinkler heads that produce mists or fine sprays. These devices result in evaporation losses.
- Use buckets rather than a hose or automatic system to water small gardens, flowers, plants, and shrubs. You have much more control over how much water goes on the plant and where it goes.
- Adjust your irrigation controller at least once a month to account for changes in the weather.
- Install a rain shutoff device, soil moisture sensor, or humidity sensor to help stop irrigation when it is not required.
- Replace misters with drip emitters.
- Request an irrigation system audit from your local utility. Many water providers offer this as a free service. It’s a great way to learn how you can more efficiently operate your sprinkler system.
- Program your controller for multiple start times (see below). More frequent, shorter irrigation cycles can reduce runoff and unnecessary deep percolation.
- Only water your landscape after the sun has gone down to reduce evaporation losses.
- Check the sprinkler system’s required operating pressure against the actual water pressure. Differences in pressure can affect operation and efficiency.
- Convert to low water use and drought resistant grass, plants, shrubs, and trees in you landscape.
During a drought emergency you may be asked to substantially restrict your outdoor watering. Drought response plans vary for place to place, but they all include irrigation restrictions. Complying with drought restrictions will almost certainly require you to reprogram your irrigation controller and possibly shutdown your system completely. Below are some tips for making the most of restricted irrigation during a drought emergency.
Alternating Day Watering
In the early stages of a drought, many response plans restrict irrigation to every other day or three days a week usually based upon your address. To comply with these restrictions you must reprogram your irrigation controller so that it only waters on the specified days. Many newer clocks keep track of the day of the week, which makes this task much easier. Older controllers may not have this feature. If your controller does not accommodate alternate day watering you have two choices: 1) manually turn your system on and off on the permitted days; or 2) get a new controller. During a drought, it may be time to consider option 2. See the Purchase Tips page for a list of features to look for in a new irrigation controller.
Water At Night
Make sure your system only operates when the sun is down to reduce evaporation losses. If you like to watch your sprinklers run, set the start time for 8:30 p.m. – there is still plenty of light outside, but the sun is usually down. Many irrigation experts feel the best time to water is between midnight at 4 a.m. because evaporation in kept to a minimum.
Repair All Leaks
Check your system for leaks. To detect a leak in your irrigation system, you must shut down all water use inside your home and be fairly certain that there is no leakage occurring indoors. Once you have done this, you can use your water meter to see if any water continues to flow into your system. To do this, follow the instructions detailed in the water meter page.
Multiple Start Times
If your irrigation controller offers the feature of multiple start times you can use this to your advantage. Most modern controllers offer the option of 2 or three start times. When this feature is implemented your system will run through the entire cycle of zones more than once per day also called cycle irrigation. Here’s an example: Instead of watering zone 1 for 20 minutes, use the multiple start time feature and set up three start times. You can then water zone 1 for 6 minutes three times for a total of 18 minutes. The shorter run times will reduce runoff and water losses and will reduce deep infiltration below the root zone. Table 1 shows a sample watering schedule using multiple start times.
Table 1: Sample watering schedule
|Zone & Plant Type||Sprinkler Type||# of Starts||Minutes Per Start||Total Minutes|
Start times: 12:30 a.m., 2:00 a.m., 3:30 a.m.
Severe Drought Actions
In a severe drought that stretches over several years automatic irrigation may be banned completely. No one hopes this day will ever come, but if it does we must all chip in and do our part. This means shutting down and possibly draining your sprinkler system. Remember, human beings throughout history have survived terrible droughts. It won’t be pleasant. It will be inconvenient. You will make it through. The actions you take will determine how much of your landscape will make it through.
OK, you no longer have an operating sprinkler system and your outdoor hose watering is all but eliminated. What do you do?
Prioritize Plants in Your Landscape
The first thing to do in this situation is to prioritize your landscape into three categories: 1) High value/must save; 2) Moderate value/try to save; and 3) Low value/save if possible.
High value plants usually include valuable trees and shrubs that have taken years to establish that will die without water. Moderate value plants might include certain perennials, newer shrubs that can be replaced, and drought tolerant Xeriscape type plants that will require little water anyway. Low value plants usually includes turf grass (which can often bounce back successfully from a complete dry out) and annuals.
The old saying is still true, “an ounce of prevention is worth a pound of cure”. If there is a drought forecast for your area – plant more drought resistant plants. See the Xeriscape section of this site for some suggestions.
Tap into Graywater Irrigation Water Sources
It’s time for drastic measures. It’s time to get creative. The more water you can capture from your faucets, shower, bathtub, and clothes washer the more plants you can probably help survive the drought. You don’t need to have an elaborate graywater collection and treatment system (although you might consider this option). Place basins in your kitchen and bathroom sinks to capture water that can then be put on plants outside. If you take a bath, don’t drain the water! Use buckets to haul the bath water outside for your thirsty plants. You can also keep a bucket in the shower with you to capture water. Capturing and reusing the clothes washer water may be more difficult, but it is certainly possible to do. If you do this, be sure to use laundry detergent that won’t harm your plants.
Place rain barrels at the bottom of your roof downspouts. If any rain does fall you’ll be able to use the water more effectively on the plants that really need it.
Ration Water Across Your Landscape
Use your ration of hose water to water hour high value plants and trees first. If nothing else, you want to make it through the drought with those plants alive. If there is sufficient water, move on to the moderate value plants, etc. If you do not have further water from the hose, use your graywater on the moderate value plants and then finally the low value plants.
Keep your moderate and low value plants on a starvation diet. Contact local hortaculturalists and plant experts to determine the minimum amount of water required to keep your plants alive. Some plants can survive (not flourish, but survive) on a small amount of water delivered once per week.
Irrigation Systems Water Use
Homes with automatic sprinkler systems use more than twice as much water on average than homes that manually irrigate with a hose and sprinkler (Mayer, et. al. 1999). This result takes into consideration difference in landscape size, but doesn’t consider landscape quality or landscaping materials (turf, Xeriscape, etc.). These results are shown in Figure 1.
Although homes equipped with automatic sprinkler systems use substantially more water than their “hose dragging” counterparts, research shows that on average these homes do not use more water than the local climate conditions indicated was required for optimum growth of turf grass (Mayer, et. al 1999).
Evapotranspiration (or ET) is a measure of the amount of water required for optimum plant growth that is based on a number of factors including temperature and precipitation. When the water use of manual and automatic irrigators is compared against the local ET rate is can be seen that on average manual irrigators applied 39% of the theoretical ET requirement and automatic irrigators applied 47% of the ET requirement. These results are shown in Figure 2. This means that although homes with automatic sprinklers use more water, they are still irrigating quite efficiently on average.
Irrigation Systems Water Savings
An automatic sprinkler system is almost always the largest user of water in a home. If you’re looking for a way to save water it makes sense to focus on the big uses. It doesn’t get any bigger than the sprinkler system.
From a horticultural standpoint, over-irrigation occurs much too often. However, it is most prevalent in the cooler fall months when summer irrigation schedules have not been revised to meet the current weather conditions. Over-irrigation causes three basic problems.
- Over-irrigation pushes water beyond the root zone and is wasted. This occurs most notably in the case of turf grass.
- Over-irrigation causes excessive run-off, which contributes to non-point source environmental pollution.
- Over-irrigation, in general, degrades plant health.
There are a number of ways to reduce outdoor water use and automatic irrigation and all of these recommendations are explored in great detail in this web site. Saving water outdoors depends on a number of factors including the type of plant material, the soil, landscaping practices, climate, irrigation system efficiency, etc. It can all be a bit overwhelming. Many water utilities offer free landscape audits. An audit is a great opportunity to meet with a local expert and discuss ways to improve efficiency on your specific landscape. Contact your utility for information on these programs.
Ways to Save Water with Your Automatic Sprinkler System
- Convert turf to low-water use Xeriscape
- Improve your irrigation schedule
- Upgrade your sprinkler clock
- Install a rain shutoff device
- Harvest rainwater
Improving irrigation efficiency is a win-win situation all around. You save money on your water bill and your landscape gets the water it needs without waste. What could be better?
Irrigation Systems Benefits and Costs
If you currently manually irrigate and you are considering installing an automatic irrigation system you can expect that your water bills will go up. Recent studies of homes with and without automatic sprinkler systems show that homes with automatic systems use substantially more water outdoors on average (Maddaus and Mayer, 2001). Automatic irrigation systems, if not properly managed, can waste a lot of water. Always be mindful that YOU are the “brains” behind your irrigation system scheduling and YOU control the controller.
The benefits of an automatic irrigation system include reduced labor for watering, convenience, full landscape coverage, the ability to control irrigation timing, and added value to your home.
The costs of an automatic irrigation system include installation costs (starting at about $1,000 for a small yard and moving up from there), water costs, maintenance costs (shutdown and startup and annual repairs), and increased landscape maintenance (you may be mowing more often).
You can minimize costs by carefully designing a system that meets the specific needs of your landscape, programming your clock properly, adjusting the program frequently in response to changes in the weather, installing a rain shutoff device or soil moisture sensor, and maintaining your system.
Cost Benefit Analysis
It is possible to quantify the costs of an automatic irrigation system, but quantifying the benefits is quite difficult. This makes a traditional cost benefit analysis virtually impossible. If you are considering installing an automatic sprinkler system you will have to weigh the costs and benefits for yourself. If you already have an automatic irrigation system, you can maximize the benefits and minimize costs and operating the system as efficiently as possible.
Here are a some tips for reducing the cost of operating and maintaining an automatic irrigation system:
- Know how to run your irrigation controller and change watering times.
- Adjust the watering times (number of minutes.) and the frequency of watering (daily, twice a week, etc.) based on weather conditions.
- Change your settings to adjust for seasonal differences and reset the timer when needed.
- Install an inexpensive rain shutoff device or soil moisture sensor.
- Check your system regularly for leaks, broken heads, and other problems.
- Only water after the sun has gone down.
- Adjust your spray and sprinkler heads to avoid watering pavements and other non-landscape areas.
- Water areas in the shade about 30 percent less than sunny areas.
- If possible use drip irrigation to water trees and shrubs.
- To eliminate runoff, set your clock to cycle 2-4 start times (no longer than 5 minutes each), 1 to 2 hours apart to allow water to soak into the soil. For example: water 3 times for 5 minutes, instead of 15 minutes all at once.
- Develop a separate drip watering schedule for trees, shrubs and flower beds.
- Aerate in the spring and fall to loosen soil and reduce runoff.
- After each aeration, top dress the area with a composted mulch. This will keep the soil loose and hold water near the roots.
Irrigation Systems Future Trends
There are lots of potential changes in store for residential irrigation systems. There are a number of exciting new technologies currently being developed and tested that could change the way we water our landscapes.
Climate Based Irrigation Control
Imagine if your sprinkler system could automatically adjust its program in response to changes in the weather. During hot and dry periods your system would water more frequently and for longer periods of time. After a heavy rain your system would not irrigate at all for at least a day, sometimes more. Sound too good to be true? It’s not that far away.
Several companies are developing irrigation controllers that apply water based on the evapotranspiration (ET) rate. ET is a measure of the amount of water required to maximize plant growth given the prevailing temperature, precipitation, cloud cover, etc.
One of these systems uses satellites and pager technology to frequently “broadcast” a new irrigation schedule to your irrigation controller. Another system uses cable TV wires to accomplish the same task. A third system has a built in ET chip that contains a detailed 20-year history of ET in the region and irrigates based on historical patterns combined with a small temperature sensor.
All of the systems hope to save water by tailoring irrigation to local weather patterns. Once a large irrigation manufacturer such as Rainbird, Hunter, or Toro adopts this concept it is expected this technology will reach a mass market.
Centralized Irrigation Control
While not a new technology, centralized irrigation control has been the exclusive domain of large systems at universities and golf courses. Centralized irrigation control is similar to the climate based systems described above, but typically consists of a small computer hooked up to a rain sensor and several soil moisture sensors. The computer schedules the irrigation everyday based on the amount of moisture currently present in the soil.
This type of system will likely become the industry standard for new irrigation systems in coming years, as the technology is now available and becoming more cost effective. Upgrading is relatively simple, and is worth considering for large irrigated lawns in areas where water is costly.
Advanced Drip Irrigation
Drip irrigation is practiced extensively in other countries, especially in the dry climates of the Middle East. Israel has long been a leader in the development of drip irrigation technology. Drip irrigation offers many advantages over spray irrigation, but to be successful it often must be integrated into landscape design ahead of time. It is anticipated that advanced drip irrigation technology will increasingly find its way into American residential landscapes in the coming years.
Last modified: September 12, 2017