Laserfiche WebLink
nontributary for purposes of his administration and permitting of wells pursuant to <br /> C.R.S. § 37-90-137(7). <br /> Rules for Sand Wash Basin. The State Engineer finds there is clear and convincing <br /> evidence supporting his adoption of rules identifying water withdrawn from the Fort <br /> Union Formation, Lance Formation, Lewis Shale, Mesaverde Group, Baxter Shale, <br /> Frontier Formation, Mowry Shale, Dakota Sandstone, Nugget Sandstone and the <br /> Hiawatha Member of the main body of the Wasatch Formation, within a delineated <br /> area of the Sand Wash Basin in Moffat County, Colorado to be nontributary for <br /> purposes of his administration and permitting of wells pursuant to C.R.S. § 37-90- <br /> 137(7). <br /> The State Engineer's finding is based upon testimonial evidence regarding an analysis <br /> performed by Phillippe Martin, P.G., C.P.G., using the Glover-Balmer method for <br /> purposes of determining the timing of depletions to stream flow resulting from <br /> withdrawal of ground water from the delineated area. The State Engineer finds that <br /> this testimony, as well as the additional evidence in the record,provides clear and <br /> convincing evidence that the rules identify nontributary areas in manner that is <br /> consistent with C.R.S. § 37-90-103(10.5), and, therefore, provides a useful tool for <br /> the State Engineer's administration and permitting of ground water wells pursuant to <br /> C.R.S. § 37-90-137(7) within the delineated area. <br /> First, for reasons previously stated, the State Engineer finds the Glover-Balmer <br /> method is an appropriate method for determining the timing of depletions to stream <br /> flow for purposes of C.R.S. §§ 37-90-103(10.5) and 37-90-137(7). <br /> Second, the State Engineer finds the inputs to the Glover-Balmer model to be <br /> appropriate. The State Engineer finds the storativity and permeability values relied <br /> upon by Mr. Martin are reasonable. The permeability values relied upon by Mr. <br /> Martin were based upon site-specific data and fall within the ranges typically found in <br /> deeper bedrock formations of this type. The State Engineer finds the use of <br /> independent, site-specific data confirmed by reference to the literature to be <br /> convincing evidence that values used were appropriate. <br /> Certain parties commented with respect to whether the proposed rules utilized <br /> appropriate values for the distance from the pumping well to the nearest potential <br /> point at which depletions could occur. These parties questioned whether the rules <br /> should generally consider all intermittent and ephemeral streams, as well as all <br /> perennial streams, as points of depletion to a "natural stream" for purposes of the <br /> definition of nontributary water at C.R.S. § 37-90-103(1.0.5). The State Engineer <br /> does not need to reach this issue with respect to these rules. In his analysis, Mr. <br /> Martin relied upon a Glover-Balmer model to calculate an offset from the boundaries <br /> of the proposed designated nontributary area. Pursuant to this analysis, the proposed <br /> area is demonstrated nontributary if there are no potential points of depletions to a <br /> Produced Nontributary Ground Water Rules 2 CCR 402-17, Statement of Basis and Purpose <br /> -19- <br />