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<br />With proper maintenance and operation, the proposed altemative is expected to have a life of in excess
<br />of 50-years. Substantial growth in the upstrearn basin, changes in land use, unexpected large sediment
<br />deposition, changes in weather patterns, changes in the highway and/or railroad crossings and
<br />overgrowth of vegetation in the chalillels could impa<:t the life. For the most part, the impacts are items
<br />that can be addressed through on-going maintenance.
<br />
<br />5. COST EFFECTIVENESS
<br />
<br />1!s.eful Life of Project
<br />
<br />Annual Maintenance Cost
<br />
<br />Appropriate measures are required to keep the planned facilities in propeT working order. An operation
<br />and maintenance plan will be provided as a part of tile design. Basically, the only op(~ration activities
<br />required are to put into place any of the required road closure structures. Maintenance will consist of
<br />regularly scheduled inspections along with periodic inspections follO'o~;ng flood events. Measures
<br />must be taken to prevent irregularities or other conditions from forming in the flood way channels,
<br />levees, and other structures which could lead to formation of jams from debris or trash, and/or repair of
<br />minor damage. With regards to the natural flow chal1Jlels and widened flood way charnels, the
<br />designated Flood Superintendent wiIJ be responsible to be certain that:
<br />
<br />· The natura1low flow channel is dear of debris or foreign objects.
<br />
<br />· The floodway channel and the natural low flow channd are not being restricted by the disposal of
<br />waste materials, building of unauthorized stmctures or other encroachments (induding planting of
<br />restricted crops).
<br />
<br />· The capacity of the floodway chimnel is not n~duced by formation of large sediment deposits.
<br />
<br />· Banks are not being damaged by wave action, wind and rain erosion, and that sloughing of banks is
<br />
<br />not occurring.
<br />
<br />· Riprap sections are in good condition with no displacement, looseness, or washing, ar,d no removal
<br />of material is occurring.
<br />
<br />· Approach channels adjacent to the floodway channel are sufficiently clear of obstructions and
<br />debris to permit proper functioning of the project.
<br />
<br />· The capacity of the floodway channel is not reduced by twes and bmsh.
<br />
<br />Immediate steps will be taken to remedy any adverse conditions disclosed by such inspections.
<br />Periodic repair and cleaning and the removal of debris and sediment as may be necessary will be
<br />completed in a manner as to insure that wetlands grasses in the natural low flow chw1Jlel remain in
<br />place.
<br />
<br />rII-34
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