In Colorado, many farms and ranches need ways to control erosion. In recognition of this need, the Colorado legislature has instituted rules governing the development and use of this type of structure. This page provides general information that you may need to know if you own or plan to build an erosion control dam.
Erosion control dams are governed under Colorado statute (see section 37-87-122, C.R.S. (1990). These types of structures may be constructed on water courses which have been determined by the state engineer to be normally dry (which for our purposes is dry more than 80% of the time). Structures of this type cannot exceed fifteen feet from the bottom of the channel to the bottom of the spillway and cannot exceed ten acre-feet at the emergency spillway level. The height of the dam is measured vertically from the lowest point of the upstream toe to the crest of the dam in contrast to those measured vertically from the centerline pursuant to section 37-87-105, C.R.S. (1990). Note: The structure can be larger than specified under section 37-87-122, however, it then will be evaluated and must be constructed pursuant to section 37-87-105.
Erosion control reservoirs may be constructed with a capacity in excess of two acre-feet if an ungated twelve inch minimum diameter outlet tube is installed and the outlet is large enough to allow for draining within a thirty six hour period any amount of water in excess of two acre-feet. If you have questions about our forms, specifications or need further information, please contact a Division Dam Safety Engineer or the Dam Safety Branch of the Division of Water Resources in Denver.