FLOOD05425

• County: Delta
• Community: Delta
• Stream Name: Gunnison, Uncompahgre River
• Basin: Gunnison
• Title: City of Delta Confluence Park Project
• Date: 10/1/1989
• Prepared For: Delta
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Floodplain Report/Masterplan

The lagoon size should be sufficient:ly large to
accommodate the launching of craft and to ;accommodate
sufficient access. otherwise the sizing should be minimized
to keep capital costs and maintenance as Low as possible.
An axis length of about 175 feet measured :from the edge of
the river and curving upstream, with an av,erage width of
about 45 feet, will provide about a 0.18-~cre pond. Actual
sizing should be based on criteria determ~ned during final
design. The width could be narrowed to adcommodate smaller
dredging equipment if desired. The pond ~hould be of
sufficient length .to allow for vehicle ingress, egress, and
launch area, yet s.till have clearance from the river and
from the parking area. The depth of the river channel
bottom at this location is at elevation 4,916. Assuming a
sediment storage depth of about 2 feet which would also
include a safety for error of estimate, the pond bottom
would be at elevation 4,914. The average overbank elevation
is about 4,927.5, requiring a 13.5-foot-deep excavation
outside of the drain. The aforementioned 'lagoon size would
require about 4,000 to 5,000 cubic yards df excavation, and
this excludes areas of the lagoon occupie~ by the existing
drain. Some existing vegetation would alSo need to be
removed. Stabilization of the slopes inside the lagoon
would not be as critical as along the riverbank since the
lagoon area would be more protected from erosive
velocities. Vegetative stabilization might be considered.
The areas upstream and downstream of the lagoon entrance,
however, should be stabilized.

Streamside Launch Site, Downstream of Drain:

This location is along a straight reach of the river,
just downstream of the lagoon type launch ;si'te, and would
provide access to 'the river from the river,bank. This site
spans from about s.tation 36000 to 36500. :The river in this
area exhibits slower flows near the left bank. The main
current bounces off the hard-point create~ by the armored
northwest corner of the confluence of the qrain and the
river. The curren't then crosses the river diagonally,
leaving a relatively Slow-flowing pool between it and the
left bank. This area also exhibits a deptp of flow suitable
for launching watercraft. There are no navicJation
obstructions downstream of this area. Approach from the
upstream may present a minor challenge since the incoming
craft would have to navigate either througp the riffle and
break out of the main current, or go around the riffle and
cross the current to the launch site. Incoming craft could
be accommodated by extending the launch area downstream a
longer distance, or providing for emergency takeout farther
downstream. In conjunction with this location, the
hardpoint previously mentioned could be fuirther armored for
safety and esthetic; reasons, and the point! thereby extended
into the river a f,~w feet. Bureau of Land, Management
kayakers and canoeists suggest this extended point could
enhance the pool area at this site for launching craft. The

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