Smart irrigation design is critical to ensuring a garden thrives.
- If a garden is under watered, it will take longer to establish itself and may lack vivacity.
- If it is overwatered, pests and rot will plague your property and inspire use of chemical pesticides and fertilizers.
- Irrigation can also support or inhibit the stability of slopes on a property.
To ensure effective water use and a happy garden, consider the following tips:
1. Allow a smart garden design to guide the irrigation plan. In the past, many would irrigate gardens with a simple sprinkler grid covering the full property. This ensures there will be areas that are perpetually too wet and others that do not get the water they need. The goal is to ensure the irrigation meets the needs of the plants within the garden.
2. Evaluate the natural flow of water on the property. Slopes, larger foliage, soil and bedrock materials can affect the flow of water on a property. Take care to ensure irrigation water and loosened slope materials will not flow toward structures. Recognize some areas of the garden may maintain a higher moisture level than others independent of irrigation.
3. Audit water sources. An effective irrigation system will recognize and account for multiple water sources. Sources may include expected rainfall as well as rainwater that can be captured using cisterns, rain barrels or managed through infiltration. It may also assess opportunities for graywater use.
4. Audit water needs. If an irrigation system is to support an existing garden, evaluating the amount of water currently needed to support various areas of the garden is smart. Areas where plants are getting more or less water than needed and areas where overhead sprinklers are watering hardscapes can also serve as a useful guide.
5. Minimize the need for irrigation with smart garden design. If the irrigation plan is to support a garden renovation, thorough understanding of the design is key. A garden designed for water conservation will place plants with similar water consumption needs together. Gardens designed this way are more likely to thrive and are also easier to irrigate. A truly smart garden design will look at ways to mitigate the need for irrigation by installing native foliage and placing foliage in areas where its sun and water needs are met naturally.
6. Design around hardscapes. Water falling on sidewalks, non-permeable patios, and wood decks creates waste, challenges public water collection systems, and can reduce the useful life of hardscapes. If using overhead sprinklers, be sure to know the radius they reach and design to avoid over-spray onto hardscapes.
7. Look into smart irrigation devices. Weather-based controllers, sub-meters, rotators and low flow irrigation devices all produce profound impact on a garden's sustainability.
Weather gauges and timers bring logic to automated irrigation systems. If it is raining, the weather gauge will prevent unneeded irrigation. A plethora of technical developments can ensure each drop makes a positive impact on a garden's health, beauty and sustainability and provide landscape managers with feedback to continually improve system performance. (See Irrigation Devices that Earn LEED registered Points, and Irrigation Devices That Earn California Rebates.)
Designing, installing and maintaining sustainable irrigation systems requires some level of technical expertise.
- Do-It-Yourselfers can prepare for the project by consulting with a Certified Irrigation Auditor.
- Also, municipalities and non-profit organizations interested in effective water use will often offer classes and resources.
- For example, the City of Santa Monica provides technical drawings and guidelines (here). We are not aware of any software that effectively aids DIY-ers in irrigation design.
- Those evaluating contractors for irrigation design and installation projects should also seek professionals with Certified Irrigation Auditor credentials to ensure the sustainability and overall utility of their irrigation system.
- Many municipalities offer significant grants to property owners updating irrigation. (The City of Santa Monica's are here.) A professional should have strong familiarity with incentives available within their area of operation and help clients secure available funding.
For more information:
Cassy Aoyagi's website offers water conservation tips(here)and much more.