Em4885 irrigation management practices to protect ground water

4 CHAPTER
Purpose
OVERALL MANAGEMENT OBJECTIVES AND
IMPLEMENTATION PRACTICES
This chapter will present six Overall Management Objectives (Objectives) and various
Implementation Practices (Practices) that can help achieve the Objectives.
Overall Management Objectives, if achieved wholly or in part, should result in one or more
of the following:
1. Minimized potential for pollution of ground and surface water.
2. Minimized water diversions for irrigation.
3. Minimized soil erosion.
4. Production of a profitable crop.
Implementation Practices are the specific management or hardware changes that will help achieve
the Objectives. For example, Objective 2.00 is to improve the irrigation performance. A specific
Practice that can help achieve this Objective is to install a runoff reuse system (IP 2.02.11). Some
Practices will be fairly specific, such as the runoff reuse system. Others may be somewhat broad,
such as the Practice to consider changing the irrigation system type (IP 2.01.08).
The various practices are presented as options to help in achieving the Objectives. The Practice,
or Practices, that will be used depends on the specific situation. One of the results of achieving the
Objectives should be to produce a profitable crop. It is expected that Practices used will be those that
help achieve the Objectives while maintaining the economic viability of the farm.
The intended, primary effects of achieving the Objective on surface and ground water quality,
water diversions (pumping a well or a river, or canal deliveries), and crop yields will be discussed in
the presentation of the Objective. It should be understood that the effects of implementing any single
Practice will vary depending on the specific situation and whether other Practices are implemented at
the same time.
For example, the intended result of using dammer/dikers is to increase infiltration and thus reduce
surface runoff. However, if good irrigation scheduling is not simultaneously practiced, an additional
result could be increased deep percolation.
There may also be secondary effects which will have to be addressed so as to not worsen a
situation. For example, a common Practice for improving furrow irrigation system uniformity is to
speed the rate of water advance down a furrow. However, faster water advance may increase erosion
and will certainly increase the amount of runoff that will have to be dealt with. Thus, many times,
two or more Practices should be implemented together to achieve the intended results.
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