Conjunctive Management Rules Proposed Boundary Changes for the Eastern Snake River Plain Aquifer

Map of the ESPA area


  1. Eastern Snake Plain Aquifer. The area of coverage of this rule is the aquifer underlying the Eastern Snake River Plain as the aquifer is defined in the report, Hydrology and Digital Simulation of the Regional Aquifer System, Eastern Snake River Plain, Idaho, USGS Professional Paper 1408-F, 1992 excluding areas south of the Snake River and west of the line separating Sections 34 and 35, Township 10 South, Range 20 East, Boise Meridian.

April 2015 Update

On November 10, 2010, Clear Springs Foods, Inc. filed a Petition to Amend Rule 50 with the Idaho Department of Water Resources ("IDWR"). Specifically, the petition requested the initiation of rulemaking to modify and amend Rule 50 of the Conjunctive Management Rules (IDAPA to enlarge the area of common groundwater for the Eastern Snake Plain Aquifer. In response to the petition, IDWR commenced a negotiated rulemaking process to examine whether Rule 50 should be amended.

After consideration of the petition to amend Rule 50, the Director proposed to delete the rule through a formal rule change. See the Director's Final Order of August 29, 2014. In accordance with established statutory procedures, the proposed rule change was submitted to the Idaho legislature for consideration during the 2015 legislative session. The legislature has the right to approve or reject a rule change, or take no action, in which case a proposed rule becomes effective. On February 24, 2015 and March 11, 2015, the Idaho House and Senate approved a concurrent resolution rejecting the Department's proposal to delete Rule 50. Consequently, the proposed rule is not adopted and rule 50 remains a valid part of the conjunctive management rules.

Questions or Comments?

If you would like further information, please contact Richard Rigby by phone at (208)-287-4839 or by e-mail: