Efficient and reasonable use of water for irrigation.

Environment Canterbury (ECan) is currently preparing a Natural Resources Regional Plan (NRRP) to manage the natural and physical resources of the Canterbury region. The NRRP sets out detailed objectives and policies for setting and managing water allocation. A major part of the available water resource is allocated for irrigation. How efficiently that water is used impacts on how water is allocated and what potential adverse environmental effects could arise. The purpose of this report is to define irrigation efficiency, recommend a reasonable and desirable level of irrigation application efficiency for use in allocating water for irrigation, and to review conditions of water use. The information will be used to develop and promote policy in the NRRP, be incorporated in a reasonable use test for setting water permits, and assist in the fair allocation of water resources with the least environmental effect. Fourteen definitions of efficiency have been described and evaluated