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 waste Lime mat:erial could be used a.s admixtures in
non-load bearin:r areas where engineering properties are not
an issue. Even in these areas, however, the, compressible
and soluble nat'~re of t:he material should be recognized in
conjunction wit:..~ the intended use. The use of lime material
as admixture to areas in contact with water and biota should
be carefully cO:..~sidered. Impacts of lime include pH effects
and chemical im:::>alance on soil and water, and the potential
effects of othet:" unrecognized contaminants in the lime. The
non-engineering properties of the lime wast:e: material have
not been addres5ed in t:his study. The lime material impacts
on the environm~nt and its various potential uses should be
assessed if its volume and location in 'the Confluence Park
area remains a '~oncern.

12. Bank StabilizatioQ.

Bank stabilization on the Uncompahgre a.nd Gunnison
Rivers is needed. because some of the ConfluE,nce Park
features and th~ nearby new sewage t:reatment: plant are
vulnerable to blnk erosion damage.

An inspect ion of the banks on t:he Uncompahgre and
Gunnison Rivers was made, and a memorandum on the bank
stabilization evaluations was provided to the City of Delta.
A synopsis of t:'le conclusions for specific s,ites of concern
is provided bel'Jw.

Uncompahgre Ri v,~r, 5th street BridCfe .Area:

Grade stabilization in this area could be warranted if
the City determines that the water diversion. intake for the
fish ponds should be located here. Grade control would
insure that app:,~opriate water surface elevation would be met
for the city's diversion, and the irrigation diversion on
the left overbank. The city may consider a combined drop
structure, dive:,~sion, and bridge replacement scenario.
Design guidance for the drop structure was provided to the
City of Delta along with illustrations of previously
constructed strnctures and additional design aids.

Uncompahgre Rivorbank by the Fish Pond:

Protection of the eroding and unveCfetated bank is
needed to inSUrE! the stability of t.he entire length of bank
near the wester:LY edge of the fish pond. As flows continue
to erode the baBe of the bank, the stability question could
become more important. The effects of the AB Lateral
Project, if conntructed, could also be of concern, since
typical river lClw flows would be boosted significantly.
Existing fill OIL top of the bank is made vulnerable to
sloughing into t:he river if undercut.

2'-
.)