Electrical Power for Valdez and the Copper River Basin-1981

Streambed sedimentation can be caused by a variety of activities.Improper construction and clearing techniques can cause increasedrunoff and excessive erosion. Clearing for penstock constructionabove ground should be limited to large shrubs and any trees whichmay be encountered to reduce ground disturbance and erosion. Adamaged streambank is unstable and can cause sedimentation.Streambanks should be restored to pre-project integrity during the. construction season in which they are damaged. Transmission lineconstruction should be initiated after the ground is frozen and somesnow cover exists to minimize erosion and rutting.Alteration of the streambed or barriers in the channel can causescouring and downstream sedimentation. Vegetation and debris shouldbe kept out of Allison Creek and any streams crossed by the transmissionline. Any structures placed in or across streams or waterbodies,as a result of project work, should be removed before theend of the current construction season. An erosion control plan anda plan for any instream work (including transmission lines) shouldbe developed prior to construction and presented foy review byresource agencies to insure appropriate precautions are implemented.Care should be taken to prevent the introduction of toxic materialsinto any waterbody. Fuels, lubricants, and other potential pollutantsshould be stored in leakproof containers within an area surroundedby a containment berm at a mintmum of 300 feet from any stream orwaterbody.Improper disposal of refuse can serve as an attractant to bears andother wildlife and lead to bear/human confrontations, usuallyresulting in removal or destruction of the bear. Feeding of wildlifeby construction crews is illegal and should not be allowed.During construction, all refuse should be placed in metal containerswith heavy lids and be removed from the site regularly.Nesting eagles can easily be disturbed by human activity which maycause them to desert eggs or young as a result. Nest removal ordisturbance of bald eagles is prohibited by the Bald Eagle Act of1940. When the exact transmission line route is established, FWSpersonnel should be given the opportunity to survey the route forany nests. Restrictions may be placed on construction activityoccurring between April 1 and July 15 if nests are found in closeproximity.Improper spacing of transmission lines can cause electrocution ofraptors. Transmission line design and construction should be governedby "Suggested Practices for Raptor Protection on Powerlines," RaptorResearch Foundation, 1975. Use of this information should be madeto design the powerline with proper grounding, spacing, and configuration,such that it will prevent the electrocution of raptors.Clearing for the transmission line could create a visually displeasingscar on the landscape. To lessen this impact, clearing for theright-of-way should be limited to that needed to string the conductorsand allow the passage of construction equipment. To further reducevisual impacts, small shrubs should be left in the right-of-way andalong the edge of clearings so the vegetation will blend with thenatural surroundings.