Colo. Rev. Stat. § 35-49-106
Anyone proposing to construct a dam for the creation of a livestock water tank, as described in section 35-49-103, shall submit to the state engineer for approval an application on a form provided by the state engineer showing the general location of such proposed dam with reference to section, township, and range, location and dimensions of spillway, and the number, location, and size of dams already constructed within the watersheds of the dry channel on which such dam is proposed to be built. Nothing contained in this section shall be construed to specify plans and specifications of such technical detail or nature as to require preparation by an engineer or construction of such stock water tanks under the supervision of an engineer; it being the intent and purpose of the provisions of this section that the state engineer shall be apprised by the completed application of pertinent information sufficient to enable the state engineer to ascertain the general location of the water tank, its operation in relation to tanks already constructed, its relative priority rights, its effect on existing appropriations of water, its capacity, its dam dimensions, the necessary and reasonable factors of safety, and its compliance with the provisions of this article.
C.R.S. § 35-49-106