Watershed Health

Colorado’s Water Plan promotes watershed health and supports the development of watershed coalitions and watershed master plans that address the needs of a diverse set of local stakeholders.

Watersheds connect terrestrial, freshwater, and coastal ecosystems. They also provide ecosystem services, such as carbon sequestration, water supply, filtration, and purification. Colorado watersheds support multi-objective uses for both consumptive and nonconsumptive water supply. Approximately 80 percent of Colorado’s population relies on forested watersheds to deliver municipal water supplies. Watershed health management strategies that protect this domestic supply will also protect other uses in the watershed.

Colorado’s mountain watersheds have a strong influence on the quality and quantity of water. Watershed geography includes physical aspects, such as climate and geology, and ecological aspects, such as stream biology; but it also examines the relationships between humans, land and water. Healthy watersheds provide ecosystem services that benefit ecological processes, local and state economies, and social stability. Ecosystem services include flow regulation, flood attenuation, water purification, erosion control, dilution and flushing of contaminants, and habitat protection.

A watershed is an area of land in which all water drains to a common point. Watersheds exist at all spatial scales, from the tiniest of tributaries to the largest rivers on earth. John Wesley Powell defined a watershed as “that area of land, a bounded hydrologic system, within which all living things are inextricably linked by their common water course and where, as humans settled, simple logic demanded that they become part of a community.” Headwater areas include forested watersheds, intermountain wetland complexes (parks), and the riparian corridors of stream valleys, and are the natural forebays of Colorado’s water supply. As water from snowmelt and rain travels down-gradient to reach rivers, it must move through varying terrain, interacting with the watershed’s biology and physical environment. This is the watershed’s ecosystem. Water quality and quantity are intimately linked to watershed health.

Broadly defined, watershed health is a measure of ecosystem structure and function. Structure refers to species richness (characterized by abundance and diversity), inorganic and organic resources, and physical attributes (including habitat complexity). Function refers to ecosystem processes such as the hydrologic cycle, nutrient cycling, energy flow, and succession. A critical component of the hydrologic cycle is flow regime. Flow regime defines the magnitude, duration, frequency, rate of change, and  timing of flows in stream systems. Magnitude refers to a river’s discharge. Duration describes the period of time during which a river experiences a given discharge. The frequency at which a river experiences a given discharge and the rate at which discharges increase and decrease (i.e. change), also characterizes flow regime. Finally, a watershed’s hydrologic function influences the timing of discharges, or seasonality.

Colorado's Water Plan sets a measurable objective to cover 80% of the locally prioritized lists of rivers with stream management plans, and 80% of critical watersheds with watershed protection plans, all by 2030.

Read Chapter 7 Water Resource Management & Protection to learn more.

IMPLEMENTATION

Watershed Management Plans

To view this on a map, go to the CWCB Data Viewer here and turn on the watershed plan layer.

For a list of watershed management plans, see Colorado's Water Plan Appendix D.