Em4885 irrigation management practices to protect ground water

2 CHAPTER
B. Development of tools needed by agencies for effective management of information
and for evaluation of programs.
C. Identification and evaluation of agricultural practices and other measures to protect
ground water from degradation by agricultural activities.
D. Effective implementation of measures to protect ground water from degradation
by agricultural activities.
E. Effective and appropriate enforcement to ensure that voluntary efforts to protect
ground water quality are not undermined.
F. Generation of adequate funding to implement recommended activities.
Objectives C and D of the strategy are addressed, in part, by the Manual. The Manual identifies
Overall Management Objectives for irrigated agriculture that, if achieved, will reduce potential
ground and surface water pollution. Implementation Practices that will help achieve those Overall
Management Objectives are also presented. Education and dissemination of this information is one
means of encouraging Growers to adopt those practices deemed applicable to their situation.
Identification of Practices to Protect Surface and Ground Water Quality
Previous efforts to identify practices that will help protect surface and ground water quality from
agricultural land-use included the 208 Irrigated Agriculture Water Quality Management Plan. This
was a two-year planning effort mandated by Section 208 of the 1972 Federal Clean Water Act. As a
part of this Plan, Management Practices for Irrigated Agriculture was published by Ecology in 1979
(DOE Publication #79-5B-1). This publication was a listing of best management practices for
irrigated agriculture which would help in protecting surface water quality.
Surface and ground waters are interrelated as recognized by the ground water protection strategy
discussed previously (see General Principle 4). Ground water is surface water (lakes, rivers, streams,
or overland flow) that has percolated into and through the ground to an aquifer. Ground water
may move back into surface waterbodies through seeps, springs, or base flow into a river or lake
depending on the geology of an area. Contaminated ground water can move into uncontaminated
aquifers or return to surface water, depending on the geology.
The Manual is a response to Section 319 of the Federal Clean Water Act which mandates
development of programs for control and reduction of nonpoint source pollution of both surface
and ground water. The Overall Management Objectives and Implementing Practices presented in
the Manual also address Objective C of the specific strategy for protection of ground water from
the activities of irrigated agriculture. The Manual addresses the interrelationship of ground and
surface water and the concurrent impact of irrigated agriculture on them. In that sense the Manual
also addresses General Principle 4 of the specific strategy, that is, protecting surface water must not
adversely affect ground water and vice versa.
18