Instream Flow Monitoring and Enforcement


The Colorado Water Conservation Board (CWCB) protects the state’s instream flow (ISF) water rights by enforcing terms and conditions contained in decrees, stipulations and agreements. The agency also monitors streamflow conditions to ensure that ISF water rights are being met and administered within the state’s prior appropriation system.


Legal Protection

CWCB staff reviews all new water right applications for potential impacts to ISF rights. If potential injury to the ISF is identified, staff and attorneys may work with the applicant to resolve issues outside of Water Court, or file Statements of Opposition (SOP) in the pending water right case. When a SOP is filed, the CWCB and the Attorney General’s Office work with the applicant to develop terms and conditions to allow the application to go forward, while providing full protection of the ISF rights. In cases where the parties cannot agree on adequate terms and conditions, the CWCB, in coordination with the Attorney General’s Office, may pursue litigation.


CWCB staff actively monitor flow conditions at more than 225 stream gages. An alert system automatically warns staff when flows drop below decreed ISF amounts. CWCB also provides financial support for the installation and operation of permanent streamgages used for water administration, recreation, and monitoring ISFs.

View Current Conditions



Instream flow water rights are administered within Colorado’s prior appropriation system just like any other water right. Staff can request administration of the ISF (“place a call”) from the Division of Water Resources to prevent injury to the ISF water right.

Instream Flow Administrative Calls 

Data Collection

CWCB staff collects streamflow measurements and other data to support all ISF recommendations. Staff may also install temporary stream gages where DWR or USGS gages do not exist to support water availability analyses