Information obtained from a video on the ucanr.edu website, urban water users (homes, landscape, schools, businesses) use less than 10% of the available water in California. 41% is used by agriculture and 51% is used to protect wild and scenic waters. While urban use is less than 10% water consumption in California (link to article) until government takes on the challenge of ground water management, replacement of aging water delivery systems, and off-river water storage facilities, California gardeners and homeowners will have to shoulder the burden of reducing water consumption, which is challenge #1. Yes, we are living in drought times. What can you do as a gardener to help conserve water and still maintain a garden? Read on...
If you do not use your lawn, consider reducing the grass area. For example, a 10'x10' lawn uses 62 gallons of water per week! Alternatives could be replacing cool weather grasses with warm weather grass, which requires less water. Xeriscaping with drought tolerant plants, using the space for edibles, or a combination of the two is a great alternative. UCANR has a great calculator for water use.
Irrigation of landscape (ornamental) trees during a drought can be accomplished with less watering. Irrigating several weeks apart with a hose in spring and summer will suffice. Irrigate long enough to wet the soil to the depth of the root zone (usually about 12-16 inches).
Fruit and nut trees need water to produce a good crop. In a drought the goal is to keep the tree alive, at the reduction of fruit production. With present recommendations from the State, crop reduction is a good alternative. If we suffer a severe drought, the amount of water available for irrigation may only be enough to keep trees alive and may not support a crop.
If you have a vegetable garden, consider growing food that requires less water. Vegetables such as squash and zucchini often fare better and can be kept alive with less watering (once or twice a week) through the season. Tomatoes, beans, and root crops such as carrots require regular watering and are not tolerant of long, dry periods. Alternatively, reduce water usage by reducing the size of your garden during the drought.
Using recycled water, or graywater, to irrigate landscape plants helps conserve water, electricity and reduces water bills. An estimated 30 to 50 percent of home water consumption results in graywater, which can be recycled into the landscape. Gray water sources include sinks, bathtubs, showers, and washing machines. While it may take some replumbing to accomplish this, the water savings can be considerable. Do not water from 9am to 7pm (during the day). This is typically the hottest part of the day, and evaporation will take needed water from the plants. Water at night, and use an irrigation timer to control the amount of water used. A great resource for information is the Drought Toolkit published by UCANR can be found here.
As always, we recommend consulting with your local UCCE Master Gardener program, local garden center or a landscape professional for more detailed information on how to water, based upon the drought conditions in your area. Please use our Help Desk link for your questions.
Note from editor: Graywater irrigation regulations may change at any time and it is important to check with local building enforcement agencies before developing plans for or installing a graywater system. If you decide to install a laundry-to-landscape graywater system, here is a helpful Graywater Design Manual. When using graywater to irrigate plants, you should avoid using household products that contain sodium or sodium compounds, bleach or boron, as these can adversely affect plants and soils resulting in an alkaline soils condition not well tolerated by many plants. The UC article "Using Household Wastewater on Plants" describes the effect on plants of using products which contain boron and chlorine. The Greywater Action website provides a list of products available that are phosphate, sodium, chlorine and boron free. The Ecology Center in Berkeley also evaluated a number of laundry products for compatibility with graywater systems and the results are listed on their website.