Work with water laws

Greenhouse growers have been challenged by the enactment and enforcement of increased water regulations over the past decade. In many areas of California , growers are mandated to obtain conditional waivers or permits and reduce loads to meet the state’s Total Maximum Daily Load requirements. Discharging polluted runoff from properties is subject to legal action.

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Cost of compliance

Substantial capital is often required to comply with regulations, especially for greenhouse operations where the best long-term solution is the construction of recycling and water-capture systems. These increased costs can potentially drive growers out of business or to relocate where regulations are not as restrictive. With increasing competition from foreign imports, skyrocketing fuel costs, labor problems, urban encroachment issues and the explosive invasion of exotic pests, concern has been voiced that increased water-quality regulations could be the final nail in the coffin for many growers.

Experience, however, is proving otherwise. In coastal California , the past five years have been a trial by fire for many growers who had not allocated much time or resources to protect water quality. What growers have learned from the painful process of suddenly dealing with tough new water regulations is that they have been able to comply, and that the impact on their businesses has been minimal. Management practices that have been implemented have demonstrated good stewardship and have benefited the industry.

Cooperative efforts to comply

Industry survival in California has been largely due to growers banding together to implement group monitoring plans. Grant and cost-share programs for growers through both the California State Water Resources Control Board and the National Resources Conservation Service have played an important role in allowing growers to implement changes that will have long-term benefits for the environment. Additionally, educational programs for growers have hastened adoption of management practices to protect water quality.

Several years ago, University of California researchers received a $2.6 million grant through the Los Angeles Water Quality Control Board to address water-quality issues in the ornamental production industry in Ventura and Los Angeles counties. The objective was to help growers implement technologies and management practices to protect water quality and to evaluate the effectiveness of the improvements.

To educate growers on the management practices that can be used in greenhouses and nurseries to protect water quality, UC personnel conducted 16 quarterly water-quality training meetings in both English and Spanish. Meetings included hands-on demonstrations and tours of operations that implemented management practices to protect water quality.

Sixty-seven greenhouse and nursery growers completed a 142-question survey that was developed to evaluate operations and areas in need of improvements. After attending an educational program for a minimum of one year, the growers completed the survey again. This enabled UC officials to assess areas of grower operations that improved because of participation in the educational program. By the end of a two-year period, statistically significant changes in many nursery practices were documented. This demonstrated how vital educational programs are in helping growers make needed changes to address water-quality issues.

Cost-share program

To help growers with the cost of implementing technologies for protecting water quality, a $1.2 million cost-share program was set up to offset up to 80 percent of the total cost of the improvements. The cost-share program was administered by the California Cut Flower Commission. A committee of growers helped evaluate the project proposals and determine project funding levels. Money was allocated to 19 improvement projects at 17 greenhouse and nursery sites.

Evaluation of improvements

Over the past two years, UC researchers have monitored flow and water quality before and after project implementation to assess effectiveness in reducing runoff at the 17 project sites. Water samples from irrigation and storm events were collected for analysis of nutrients and pesticides. At sites without irrigation runoff, lysimeters were used to sample leached water. Other data were collected, including water use and irrigation distribution uniformity.

Recycling systems dramatically reduced runoff. Water flowing into these systems had the highest nutrient concentrations of any project improvement group. There was no measurable runoff from irrigation events leaving the properties once these projects were completed and considerable runoff is expected to be collected from future storm events.

Reduction in runoff using detention basins was comparable to the recycling project results. However, leaching losses of some constituents, particularly nitrates, and potential groundwater contamination may be a consideration for unlined basins.

Financial benefits

Though substantial capital was involved in implementing these improvements, growers will eventually recoup their costs and receive long-term financial benefits. This is especially the case for recycling systems.

Water savings for recycling systems was 136,000 gallons per acre per year, as a median value, and increased with nursery size. Because nutrients in the recycled water are reused at these sites, these systems also reduce fertilizer costs.

Even simple irrigation retrofits can translate into water savings. Irrigation upgrade projects increased the uniformity of irrigation water application by 10 to 50 percent. One grower in the project saved an estimated 19,000 gallons of water per acre per irrigation-hour by improving the efficiency of his irrigation system.

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- Julie Newman