STEWARDS OF OUR WATERSHED --

What farmers and landscape professionals can do to protect our watershed and groundwater resources 

Zone 7 Home

Note:  Contact Zone 7 to receive the following information as a brochure.

Stewards of the land . . . and water resources, too!

The days of the ranchos are long past, yet the Valley's flourishing vineyards and rolling grasslands continue to reflect its rich agricultural heritage. Likewise, the many lush parks and golf courses remind city dwellers that there is more to life than hectic workaday schedules.

As someone responsible for keeping crops or turfgrass green and thriving, you have a healthy respect for Nature and the environment, and a long-standing reputation as a "steward of the land."

But just as you care for your own property or that enjoyed by the public, your stewardship extends to our Alameda Creek Watershed, the landscape over which water flows on its way to the Bay or percolates down to the Livermore-Amador Valley Main Groundwater Basin.

As the water recycles through Nature's hydrologic cycle and flows over the watershed, it picks up impurities, some of which are the direct effect of human activity and other contributors to nonpoint source pollution. During times of high flows, pollutants that find their way into the creek may reach the Bay, harming fish and other wildlife. During the dry summer months, there is little or no outflow to the Bay, so dissolved solids ("salts") and pollutants remain in our watershed and adversely affect the groundwater-the Valley's single most important local source of drinking water. 

The Hidden Resource  

What many residents of the Valley fail to recognize-or take too much for granted-is that we live and work atop a major water source. The Livermore-Amador Valley Main Groundwater Basin stores over 225,000 acre-feet of usable groundwater and serves as a vast "savings account" from which water is withdrawn and replaced. During years of normal rainfall, it contributes about 15 percent of the Valley's water supply. In the event of a prolonged drought, enough water can be stored there to augment the reduced surface supplies to meet the needs of the entire population for seven years or more. 

Just as farming and landscaping practices can have an impact on our more readily observed surface waters, they also affect our groundwater basin. Once groundwater becomes contaminated, it is difficult and costly to clean. We can ill afford to abandon such a valuable source of water, which would only place that much more pressure on heavily tapped surface supplies.

The key word is prevention. The best way to protect both surface water and groundwater is through prudent land and water use practices that keep contamination from happening in the first place.

GROUNDWATER AND NATURE'S WATER CYCLE Contrary to popular images, groundwater is not found in underground rivers or lakes. It is stored in porous formations (aquifers) made up of sand or gravel, with layers of silt or clay above and below. As it travels through the aquifer, groundwater may come to the earth's surface in a spring or swamp. As an important part of Nature's hydrologic cycle, groundwater is continually replaced by a supply that percolates downward from the surface, either naturally or intentionally. Just a few of the ways water reaches the basin are natural recharge from streams, as water percolates through sand and gravel in the stream bed; crop and landscape irrigation; and manmade percolation ponds and injection wells. Years ago, groundwater was considered relatively impervious to pollution, because it was believed that the soil above filtered contaminants. Within the past 20 years, however, major advances in chemical detection have shown this is not the case. Just like our more readily observed surface waters, groundwater also must be protected from pollution.

You Can Make a Difference

Crop-protection materials and fertilizers, gasoline and diesel fuels, even the tires on your equipment . . . all have pollution potential if not handled with care.

The following are just a few of the many steps you can take to guard against future problems. For more information, please contact your local UC Cooperative Extension adviser, nursery supplier, pest control adviser, agricultural commissioner's office or one of the many other organizations or agencies listed on the back of this brochure.  

Balance Your Water Budget  

If you can balance your checkbook, you can balance the amount of water entering and leaving the soil, thus optimizing irrigation water and preventing polluting runoff. 

One of the keys to keeping a water budget is taking advantage of the free California Irrigation Management Information System (CIMIS) developed by the Department of Water Resources nearly two decades ago. CIMIS now collects climatological data from more than 95 computerized weather stations across California. Based on weather data, CIMIS's central computer estimates the "reference evapotranspiration" (ETo) of irrigated grass (the "reference crop") at the station site. Using a conversion factor ("crop coefficient") and ETo, the water use of a specific crop or planting can be estimated. CIMIS can be accessed via telephone or computer. Information on calculating the water budget to estimate how much of this resource your plants are using also can be found at the CIMIS Web site. ET information specific to the Tri-Valley area also can be found on Zone 7's web site (www.zone7water.com).  

Landscape professionals can find out more about water budgeting and conducting a "water audit" by contacting the Irrigation Training and Research Center at California Polytechnic State University-San Luis Obispo. Together with the U.S. Bureau of Reclamation, ITRC offers a two-week Designer/Manager School of Irrigation at the Cal Poly campus. Shorter courses are offered elsewhere in the state and landscape water management software alsi is available from ITRC (see back panel for CIMIS and ITRC contacts).  

Other irrigation- and drainage-related tips include:

• When water is applied it affects the salt balance of the groundwater basin, so irrigate during times of low evaporation. Not only are plants and grass short-changed if watered when evaporation is high, the evaporating water leaves behind salts, which eventually percolate into the groundwater basin.  

• No single method off irrigation is "best." Research and design your system and prepare your soil so water is distributed and drains evenly.  

• There is a strong link between misapplication of water and all sorts of other problems. Too little can stunt plants, resulting in poor root systems and slow growth. Too much water damages roots by depriving them of oxygen and creates conditions conducive to disease.  

• Changes in soil's natural ability to absorb runoff means increased runoff of pollutants and sediments, all of which impact surface water and groundwater. The time of year also affects runoff. For example, fertilizing or placing topsoil during the rainy season hastens runoff.

Make IPM Part of Your Program

Just about anyone who makes his or her living from the land has at least a passing familiarity with integrated pest management (IPM). This comprehensive and effective systems approach encompasses pest prevention, identification, monitoring and environmentally sound control.

IPM is nothing new, nor is it "organic" farming. But by incorporating IPM into your own program, you not only manage pests in the most environment-friendly way and avoid resistance problems down the road, you help protect the watershed by reducing your use of conventional pesticides. You may save money, too!

• Proper pest identification and monitoring are cornerstones of IPM. The University of California publishes helpful guides to pest identification (check with your local farm adviser). For larger plots, pheromone traps and other monitoring devices can give a snapshot of what's happening in the field. Smaller farmers can do their own visual field check. Do this at least once a week, more often during the peak growing season.  

• Beneficial insects and other biocontrol agents can be a plant's best friend-and pests' worst enemy. Flowering plants may provide vital habitat for beneficials, as do properly managed cover crops.

• Sanitation helps eliminate sources of new pest populations. Transplants and greenhouse stock should be carefully checked for aphids, diseases, nematodes, and other pests (make sure your supplier has precautions in place to prevent infestations). Destroy any plants or prunings that might be infested.

• Plant pest- and disease-resistant varieties, when possible.  

• Never apply crop protection materials or other chemicals when forecasts call for rain.  

• When monitoring points up a pest outbreak, use the "softest" materials you can, such as insecticidal soaps, pyrethrin-based insecticides, Bacillus thuringiensis (B.t.), horticultural oils, or insect growth regulators (IGRs) to interrupt pests' reproductive cycles but not affect their natural enemies.  

• Always follow the label instructions for application and timing.  

• Keep accurate records so you'll know what was applied, when, where, and how much.  

• Empty, discarded containers may harbor traces of residue that could spell trouble if not properly disposed.

Other Potential Problems-And Solutions

Nitrogen fertilizers have long helped boost productivity and made turf green. Their environmentally safe and agronomically sound use and handling are key to keeping nitrate contamination at bay. Nitrate is a particular concern with private wells, which may be less protected from contamination than public wells. High levels can cause "blue baby" syndrome, a rare but sometimes fatal disease in infants and kidney dialysis patients.

• To achieve proper nitrogen balance for crops and lawns, and at the same time avoid pollution, always follow the manufacturer's instructions.  

• Have your soil tested each year by a reputable commercial lab to point up nutrient deficiencies, excess salts and pH problems, and to indicate if soil amendments are effective.

• Composting may help reduce nitrate pollution associated with some agricultural practices. Done properly, it also destroys most crop and weed residues and controls pests harbored there. The compost can then be incorporated into the soil to add organic matter or may be used as a mulch.  

• Livestock wastes and septic tank leach fields also can contribute to nitrate contamination of groundwater. Proper permitting and siting of any private wells is critical. Contact Zone 7 for more information.

• Situate livestock pens and other facilities away from wells and anywhere wastes can be washed into creeks, arroyos, or bodies of water.

• Incorporate organic matter into the soil a little at a time (too much can provide an environment for pests).

• Vehicles not only are a source of air pollution-they contaminate water, too. Minimize their use to the extent possible, and keep them and all your equipment leak-free with proper maintenance.

• Use a broom, not a hose, to clean up chemical spills around workplaces. Sawdust or cornmeal can be used to absorb liquids before sweeping up and disposing in a trash can.

• Never dispose of toxic materials down the drain or on the soil.

• Report spills or illegal dumping!

TO FIND OUT MORE

UC Cooperative Extension 1-510-567-6812

California Fertilizer Association 1-916-441-1584  www.calfertilizer.org

Cal/EPA Department of Pesticide Regulation 1-916-445-3846  www.cdpr.ca.gov

California Department of Food and Agriculture  www.cdfa.ca.gov

DWR - CIMIS 1-800-922-4647 wwwdpla.water.ca.gov/cgi-bin/cimis/ cimis/hq/main.pl

Integrated Pest Management www.ipm.ucdavis.edu

Western Crop Protection Association 1-916-568-3660 www.scpa.org

Alameda County Urban Runoff Clean Water Program 1-510-670-5543 www.co.alameda.ca.us.pwa/water.htm

Alameda County Waste Management Authority 1-510-639-2498 www.stopwaste.org

PROTECTING OUR WATER RESOURCES

Zone 7 Water Agency has numerous public committees and programs aimed at managing and protecting both surface water and groundwater supplies.

Zone 7 recently took responsibility as the lead agency working toward protection of the Alameda Creek Watershed. The Alameda Creek Watershed Management Program is guided by a steering committee made up of many interested parties who meet the first Wednesday of each month at 1:30 p.m. in the Zone 7 Board Room (5997 Parkside Dr., Pleasanton). The public is invited to attend.

This brochure was produced as part of a grant to Zone 7 to inform the public of the local groundwater resource and what can be done to protect the watershed. The grant project includes activities such as workshops, field trips, school programs and presentations to civic groups. The grant, which is a share of funds from the U.S. Environmental Protection Agency to the State Water Resources Control Board, is administered through the Regional Water Quality Control Board.

Additionally, Zone 7's Groundwater Management Program helps ensure that acceptable water levels within the basin are maintained by artificially recharging (refilling) the basin and monitoring water levels. A Groundwater Management Advisory Committee (GMAC), made up of local citizens, was formed by Zone 7 in 1995 to address groundwater-related issues that could potentially impact the Valley. Zone 7's Salt Management Program further safeguards groundwater quality, as does its well-permitting program, which provides an early warning system for toxic sites within the basin.