Water 101

Did you know?

Colorado water law is based on the prior appropriation doctrine - a system based on “first in time, first in right.”  For example, a water right put to “beneficial use” in 1865 is senior to any subsequent water rights, regardless of its use.  Thus, an 1865 right is entitled to divert all of its water before, say an 1870 right.  The entire Colorado water system is based on this timeline of water rights with the senior rights having the first priority to divert and use water.

In addition, alluvial wells (wells that are fed from surface water sources) are considered “tributary” (i.e. part of or integral to) to the river system.  As a result, pumping these wells depletes water within the river system that historically went to satisfy senior downstream water rights.  Since pumping from alluvial wells was made possible only with the advent of modern electrical supplies and pumping equipment, almost all alluvial wells are junior to surface diversions.  To ensure downstream senior water rights are not injured from these junior depletions in the river system, the State Engineer’s Office requires these wells to have an “augmentation plan.”  These replacement plans provide a mechanism to replace water back to the stream to “augment” the river system for junior water that was pumped and consumed prior to senior water rights.  By execution of an augmentation plan, the resources of the river can be maximized while simultaneously ensuring the rights of both junior and senior water holders are not injured. 


Another water supply source is an aquifer.  Aquifer water is water that has been geologically trapped below ground in large reservoirs.  As an example, the Denver Basin Aquifers (which consist of the Dawson, Denver, Arapahoe, and Laramie Fox Hills aquifers) extend from Greeley to Colorado Springs and from the foothills to Limon.  These aquifers are stacked on top of each other similar to layers of an onion.  Entitlement to this groundwater is based on land ownership.  The vast majority of this groundwater is considered non-tributary (i.e. is not part of the river system) and does not require augmentation.  Even though there are vast quantities of water within these aquifers, it is not an infinite source and many are concerned about the long term affects of mining this precious resource.

Colorado Water Law while simple in concept can be extremely challenging to manage and understand in practice.  Of course it only gets more complicated with time as many competing interests pursue the West’s most precious resource and Clear Water Solutions takes great pride in our accomplishments in this challenging field.