S8_11-15-04

• Basin: Statewide
• Title: SWSI Phase 1 Report - Section 8 Options for Meeting Future Water Needs
• Date: 11/15/2004
• Author: CWCB
• SWSI - Doc Type: Final Report

Section 8
Options for Meeting Future Water Needs
^ Agricultural use can be preserved by allowing
alternative uses on an interim basis, without a
permanent dry up.
^ A better or more stable income to agricultural users
can be provided, since the net income from a lease
can exceed the revenue that would be realized from
farming in a dry year.
^ Provides for flexibility in water management, as there
is a free market mechanism through which water
supplies can be transferred within a basin.
The potential issues and conflicts with the use of water
banks for meeting future water needs include:
^ Water may not be available from the water bank when
needed. There is no guarantee or requirement for a
party to place its water in a bank.
^ Determination of transferable amount can be
complicated and other water users must be protected.
^ Soil, weed, labor, and equipment management issues
must be considered during those years when
irrigation is not occurring.
^ Challenges in starting a market. An entity needs to be
responsible for implementing advertising and
maintaining the Bank.
8.2.3 Development of Additional Storage
Storage projects capture water during high flow years
and seasons to be used during low flow periods. These
storage projects include the construction of new
reservoirs, enlargement of existing reservoirs, or
rehabilitation of existing reservoirs that have reduced
storage volumes due to various structural problems (e.g.,
spillways unable to meet the current probable maximum
flood criteria, etc.). Storage options included in the SWSI
process include the construction of new storage facilities
to capture legally available flows under a new water
rights appropriation, the construction of new storage
facilities to maximize the yields of existing water rights,
including exchange priorities and conditional storage
rights, and the enlargement of existing reservoirs. The
rehabilitation of existing reservoirs that are under
voluntary or mandatory storage restrictions was
evaluated during the Basin Roundtable process. It was
determined that while there are many reservoirs with
restricted capacities, the total potential storage to be
gained from rehabilitation efforts is small in comparison
to Colorado's overall need. This issue is discussed in
greater detail in Section 10.
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8.2.3.1 New Storage Projects
New storage projects include the construction of dam
embankments to create on-channel or off-channel
reservoirs. Off-channel reservoirs require the
construction of diversion or pumping facilities from the
river or stream to deliver the diverted water to storage.
Another option for the development of new storage is the
conversion of gravel pits to gravel lakes. These lakes are
formed by reclaiming and lining pits created through
gravel mining operations. Diversion or pumping facilities
are also required to deliver water to gravel lakes. Storage
options will vary greatly in their feasibility, and project
considerations, such as firm yield, capital costs, and
permitting are site specific.
The benefits of developing new storage projects include:
^ Water sources will be diversified if the water to be
stored is from a new source. This can reduce the risk
of supply shortfalls as not all water sources may
experience shortages at the same time.
^ The development of storage to capture
unappropriated water can potentially reduce the
pressure to transfer water from existing uses (i.e.,
agricultural water) to meet future water needs.
The reliability of the overall water supply system can
be increased and the risks reduced. The development
of additional new storage can help protect against
potential water shortages due to structural failures
such as storage restrictions or the temporary inability
to use a supply due to water quality concerns such as
those associated with a forest fire in the watershed.
^ Existing water rights are not affected if the water to be
stored is under a new water right.
^ The development of storage for unappropriated water
captures an unused resource.
^ The development of storage maximizes compact
entitlements for beneficial use within the State of
Colorado.
^ Overall system efficiencies are increased by
minimizing system spills.
^ The yields of exchanges and non-potable reuse for
irrigation are increased. Maximizing the reuse of
consumable return flows requires storage, since
return flows occur year-round, but reuse for irrigation
only occurs during the summer months.
^ Storage is required to firm the yield of transfers of
agricultural water rights. If storage is not constructed,
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