SWSI Environment and Recreation Needs and Priorities TRT Draft

• Technical Roundtable: Recreation & Environment
• Title: SWSI - Environment and Recreation Needs and Priorities White Paper
• SWSI II - Doc Type: White Papers

COLORADO'S INSTREAM FLOW PROGRAM - HOW IT WORKS
AND WHY IT'S GOOD FOR COLORADO

Dan Merriman1, Anne M. Janicki2

COLORADO'S INSTREAM FLOW PROGRAM

History

In the early 1970's, the environment was at the forefront of the nation's agenda and Colorado's
focus was no different. Colorado mountain streams were being tapped to meet urban water needs, and
federal minimum bypass flow requirements at diversion structures were not protected from diversion
past the point of release. In 1973, the Colorado legislature recognized the need to "correlate the activities
of mankind with some reasonable preservation of the natural environment" and passed Senate Bill 97
creating the State's Instream Flow Program. This program, one of the first of its kind, vested the Colorado
Water Conservation Board (CWCB) with exclusive authority to protect streamflow through a reach of
stream rather than just at a point, and to protect levels in natural lakes. Until this law was passed, all
appropriations of water in Colorado were required to divert water from its natural course in the stream.
SB 97 removed the diversion requirement for the CWCB and allowed the Board to appropriate water
"instream" .

In Colorado, diversion and use of water is governed by the Prior Appropriation Doctrine, and to be
enforceable, water rights must be assigned priorities and decreed by the Water Court. Sometimes referred to as "fIrst
in time, first in right", the Doctrine awards priorities to water rights based on dates of appropriation. Better priorities
are assigned to early claims for water from a stream than to those rights with later claims. With the exception of
instream flow or natural lake level claims by the CWCB, all water rights claimed in Colorado must demonstrate that
water has been diverted, or otherwise captured, possessed or controlled and applied to a beneficial use in order to be
awarded a decree by the Water Court. An instream flow or natural lake level water right is unique in the system.
These rights are "in-channel" or "in-lake" appropriations of water made exclusively by the CWCB for a specific lake
or reach of stream for the purpose of preserving the natural environment. Once decreed by the water court, these
water rights are assigned a priority, just as any other water right claim, and administered within the State's water
right priority system.

Since 1973, Colorado has passed additional legislation to clarify and strengthen the program. In addition to
the authorities granted for new appropriations of water rights, the legislature clarified the CWCB's authority to
acquire existing, decreed senior water rights on a voluntary basis from willing owners for instream flow uses. This
authority allows the CWCB to improve the natural environment by adding water to streams or restoring native
flows. Most recently, the legislature clarified the CWCB's authority to accept temporary loans or leases of water
for instream flows or natural lakes.

Since 1973, Colorado has appropriated instream flow water rights covering over 8,500 miles of stream and
486 natural lakes. This protection represents approximately 30% of the perennial stream miles in the state. In
addition, the CWCB has completed 21 water acquisition transactions, including acquisitions to protect critical
habitat for endangered species on the Yampa River, to improve the natural environment of the Blue River
downstream from Dillon Reservoir, and to restore native flows to a degraded stream system near Silverton,
Colorado.

1 Chief, Stream and Lake Protection Section, Colorado Water Conservation Board
2 Sr. Water Resource Specialist, Stream and Lake Protection Section, Colorado Water Conservation Board