| Home  | The District | Drainage | Links | Reference Library | Water Conservation | Water Supply |

Cost-Share Programs

Irrigation Guide

USBR Water Manage- 
ment Plan

Water Management Handbook

Water Quality Data

Establishment of this site was supported by a water conserv-ation grant from the USBR.

WATER CONSERVATION

Westlands Water District has a limited surface water supply, and as such, water conservation techniques are practiced every day by west side farmers. In seven of the last nine years, the District has received less than its full Central Valley Project contract water entitlement of 1,150,000 acre-feet annually; current estimates in 1996 were that the District would only receive 70% to 75% of this CVP entitlement.  Current estimates in 2000 are that the District will only receive about 65% to 70% of this entitlement

Even with a full CVP entitlement, Westlands farmers would not have all of the water needed to produce crops on all of the available land, as there is a shortage of about 100,000 acre-feet. Therefore, the farmers have become experts at maximizing the efficiency of each irrigation.

Background

Only recently has it become mandatory for districts under contract for federal water to develop a water conservation plan. Westlands was ahead of its time, with the implementation of a Water Conservation Program in 1972, known as the Irrigation Management Services Program. Its main objectives were to provide information on crop water use and to advise farmers on up-to-date irrigation techniques and systems. In 1978, the District’s water conservation staff developed the Irrigation Guideto replace the original program, providing crop water use information on a weekly basis to all Westlands’ farmers. The goal was to help farmers estimate the crop water use in their particular area and to effectively schedule the amount and timing of crop irrigations. This publication is still used today, with different versions printed for three different regions in the District, reflecting the various micro-climates.

In 1981, Westlands expanded its Water Conservation program, with the development of the Water Conservation and Management Handbook. This handbook provided information about specific conditions in the District, including soil and crop characteristics, irrigation scheduling, water use planning and much more. Westlands’ staff continues to update and expand the handbook as it is still used today, with a new name of Irrigation Management Handbook. A few years later, the Water Conservation and Management Program evolved into the Irrigation Improvement Program, which provided financial assistance to farmers to obtain the services of an irrigation consultant. This program promoted many other water conservation ideas and activities, which are widely used today.

Westlands prepared a Water Conservation Plan in 1986, as required by the 1982 Reclamation Reform Act. The plan included conservation goals for the next five years. The program today continues to provide water management information and has been expanded to include low-interest cost-share loan programs for irrigation equipment and systems. The District continues to push forward, exploring new opportunities for growth and progress.

Water conservation is not a new focus for Westlands. Over the years, the District has worked to educate its water users, through the use of programs, publications and workshops. The farmers also have committed their resources to implementing new methods of conserving water.

Efficiency

Westlands’ farmers continue to have one of the highest seasonal application efficiency ratings in the nation, with a 20-year average of 83 percent . The District is committed to improve this rating even further; however there are a couple of factors to consider.

A key factor that limits projected on-farm efficiency is the distribution of the water since it is nearly impossible to put all of the water on the field at once. There is little uniformity when irrigation water is distributed to the different areas in the field, as the water moves through the root zone at different rates. District farmers utilize many different irrigation techniques to improve uniformity of irrigations to address this issue.

Another factor is the level of salt build-up , which accumulates from the use of surface water supplies. Application of water above that which is required by the crop is necessary to leach these salts from the root zone in order to maintain the productivity of the land. Failure to apply this leaching component can ultimately destroy the land, and with it, the jobs and economic activity of the Valley’s number one industry.

Not only does improved irrigation efficiency help maximize limited water supplies, it is an important part of a successful farm management program. More efficient irrigation can help:

• increase crop yield;

• improve crop quality;

• reduce and conserve water, energy and money; and

• reduce other, on-farm production costs like labor and fertilizers.

Water Meters

Unlike many agricultural water delivery agencies, water in Westlands is metered. All of the water delivered, whether it is for agricultural or non-agricultural purposes, is recorded by over 3,700 on-farm meters as well as meters on the San Luis Canal. The water is distributed to each farmer in a highly efficient closed pipeline distribution system.

Water meters are required at each District delivery and on private wells participating in any of the District’s conjunctive use programs. The meters provide accurate data which help water managers allocate limited supplies and recoup true delivery costs. In addition, farmers can calculate their irrigation efficiency, by knowing the precise amount of water delivered. This information is used by computer software programs which can perform individual irrigation diagnostic tests to assist on-farm water management.

To ensure accuracy, all meters are placed on a preventive maintenance cycle ensuring each meter is calibrated and tested every three-to-four years. Accurate metering allows both the farmers and the District to carefully manage and account for all water delivered. Other programs are built on the foundation of a solid metering program.

Groundwater Management

The Groundwater Management Plan was designed to preserve and enhance the groundwater resources within the District, with respect to both quantity and quality. Groundwater measurement and quality testing have proven useful to individual farmers to help them better manage water supplies, facilitate more accurate irrigation scheduling, monitor pump efficiency, and participate in District groundwater programs. Such measurement and testing also enables the District to better monitor groundwater supplies, calculate drought effects and determine water needs.

Deep groundwater is monitored, providing information on the quality and depth of the groundwater. This allows farmers to assess groundwater development and options at a much lower cost than if they had to obtain the information on their own.

Irrigation Techniques

Westlands’ farmers have modified their irrigation programs to maximize the limited supplies, recognizing that a diversified crop mix depends on equally-as-diversified and flexible irrigation systems. Farmers continue to use irrigation systems with higher efficiency, as shown in the following table.

Table 1: On-Farm Irrigation Systems

The popularity of the combination of sprinkler and furrow systems can be attributed to the practice of pre-plant irrigation, commonly called pre-irrigation. The Central San Joaquin Valley does not get enough rainfall to provide farmers with all of the water needed for pre-irrigation. Therefore, during the winter, some of the farmers in the District begin to pre-irrigate the land. A sprinkler system can be an efficient technique, allowing farmers to apply water to the fields before they begin to plant. The goal is to fill the soil profile with water as far down as the plant roots are expected to grow. Pre-irrigation helps to ensure the plants will have enough water to sustain growth during the hot summer months. Once the crop plants have been established, farmers will switch to a well-managed furrow irrigation program, depending on the type of crop and the stage of its development.

Low - Interest Loans

Since 1996 Westlands has facilitated the availability of low-interest loans for the lease/purchase of irrigation equipment and systems. Most recently, the District’s Expanded Irrigation System Improvement Program was approved by the State Water Resources Control Board and provides low-interest loans to purchase sprinklers, micro-irrigation, linear-move or center-pivots and/or tailwater reuse systems. The lease/purchase arrangement extends over four years. The loans encourage the farmers to try new irrigation techniques while the District and State help off-set the cost of capital.

Conclusion

When it comes to water conservation, Westlands and the farmers in the District continue to push forward. Both have a commitment to maximize a limited water supply and minimize drainage problems by promoting efficient irrigation.

Farmers, like their urban neighbors, share the same values and concerns on water conservation. They recognize the need for a balanced and reasonable allocation of water, an increasingly limited resource. Farmers also recognize that a crop requires a certain amount of water in order to grow and produce the food or fiber products. If too little water is applied, the plant will not be able to set a crop. Conversely, if too much water is applied, the plant’s roots can drown and irrigation water will be wasted.

Westlands’ farmers rely on advanced irrigation technology and management to more efficiently use their water allocation while eliminating waste. Ultimately, consumers are the ones who benefit from a farmer’s use of water, since it generates food and fiber products, jobs and economic activity for our region, state and nation.

All of us depend on water. Conservation of this precious resource is a job that belongs to everyone.