Colo. Rev. Stat. § 35-49-108
When such a dam is completed the state engineer shall be notified of such completion and, thereafter, may inspect said stock water tank. If the state engineer finds that the construction fails to conform with the application approved by the state engineer, it then becomes the duty of the owner of such dam to make such change and corrections therein as the state engineer has determined to be necessary to correct such failure, and when the same have been made, the state engineer shall provide in writing approval of such structure. Approval shall be granted by the state engineer upon reasonable compliance with the approved application and standard specifications. A livestock water tank shall not be disapproved because of failure to observe technical engineering details in construction.
C.R.S. § 35-49-108