75C - PH - BRISTOL EIR FROM WARNER TO ST. ANDREW

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The three proposed alternatives envision widening of the existing 53 -foot wide bridge across Santiago Creek to accommodate six through travel lanes. A bridge evaluation report prepared by Willdan Associates in 1986 indicates that it is feasible to widen the existing bridge in lieu of replacing it entirely. Although the specific design for the widened bridge has not been developed at this stage, it is envisioned that the bridge will be widened to nearly 120 feet consistent with the proposed street right -of -way, thereby encroaching into further portions of the Santiago Creek streambed. Based on a preliminary evaluation of the live load carrying capacity of the existing bridge structure, it appears that the existing bridge will not have to be rebuilt as part of the total bridge widening effort. An additional bridge span, adjacent to the existing bridge, is presently contemplated as the probable means of widening the bridge. This would be accomplished by either a single - span or double -span bridge structure; neither bridge design would require any fill within Santiago Creek. A single -span bridge would be supported by abutments located atop the creek banks on either side of the creek. A double - span bridge would include a central pier support within the creek bottom, in addition to the two abutments atop both sides of the creek. The central support would be sunk deep below the level of the creek bottom and would require no fill. Any minor reduction in the creek capacity resulting from the expansion to the bridge would be replaced by either raising the level of the bridge or by widening the sides of the creek. In consultation with the United States Army Corps of Engineers, it was determined that the proposed bridge construction will be covered under the nationwide permit for discharges of dredged or fill material into non -tidal rivers, streams, and their lakes and impoundments, including adjacent wetlands, that are located above the headwaters, which would cause the loss or substantial adverse modification of less than one acre of such waters (Section 330.5 (a)(26)(i)) of the Federal Clean Water Act. As long as the City complies with specific nationwide permit conditions in Section 330.5 (b), an individual permit is not required. Bridge construction plans will also be submitted to the California Department of Fish and Game, Region 5, to determine whether a Streambed Alteration Permit will be required, pursuant to Section 1601 of the State Fish and Game Code. If so, plans will incorporate the applicable permit requirements. As indicated in Section III.4.5, Dr. Richard Vogl, a recognized wetlands expert, prepared an assessment of the Santiago Creek channel's biota. The following impact discussion is based on Dr. Vogl's analysis. IM 75C -140