Em4885 irrigation management practices to protect ground water

Possible Effects on Surface Water Quality
With sprinkle and trickle irrigation system types there should be little, if any, surface runoff.
To the extent that implementing practices associated with these systems reduces or eliminates
existing surface runoff, surface water quality will be protected.
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CHAPTER 4
Furrow/rill and border strip irrigation systems create surface runoff as a normal matter of
operation. Thus, they have a built-in potential to increase the detachment process. And, if the
surface runoff returns to a natural water course it becomes a transport mechanism as well.
Depending on the current management, some of the Implementation Practices intended to increase
distribution uniformity could increase the potential amount of surface runoff.
If a runoff-reuse system is installed (IP 2.02.11) surface runoff should stay on the individual farm.
However, it is important to achieve Overall Management Objectives 3.00 and 4.00 to minimize the
effects of the detachment process. That is, given that surface runoff will occur, minimize the amount
of nutrients and chemicals that are available to be carried by that runoff. Finally, Objective 5.00 is
important for managing any surface runoff that is produced.
Again, as noted in the discussion of possible yield benefits, improved irrigation performance
contributes to a crop that is less susceptible to diseases and insects. Thus, chemical applications
may be reduced.
SECTION 1 - PRACTICES FOR ALL
IRRIGATION SYSTEM TYPES
The Implementation Practices in this section are actions that are applicable to any irrigation
system. They should be part of any on-farm program for preventing contamination of surface and
ground water.
IP 2.01.01 - Measure All Water Applications Accurately
Objective
Measure applied water so that knowledge of how much to irrigate, gained from some form
of irrigation scheduling or just feeling the soil in the root zone, can be used properly.
Description
The basis for modern irrigation management is knowing how much water is being applied
and where. Accurate measurement of water deliveries is essential. There are devices and
techniques for use in open channels (ditches, streams, rivers) or pipelines.