2017-046 - Approving Addendum Nos. 1 and 2

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+� OCTA I Santa Ana/Garden Grove Fixed Guideway Project J Visual Impact Analysis Re-evaluation Technical Memo Supplemental visual impactanalyses of the potential change in Visual contextfrom the minor design modifications at Westminster Avenue Bridge and the Santa Ana River Bridge was performed and compared againstthe previously approved analysis. The visual impact of two wire catenarywithin the PE ROWis considered to be not adverse/less than significant in the contextof the prioranalysis and presence of overhead wires in adjacent areas, therefore no supplemental visual analysis was performed for this change. Westminster Avenue Bridge — Segment 1 (Visual Character Area A) The visual character of Area Awithin Segment 1 is influenced byadjacent commercial and residential developmentthatborders the PE ROWand contains existing roadways, streettrees, and residential neighborhoods. As provided in the 2015 EA, the visual qualityof Area Ais considered Moderate Low to Moderate. Under existing conditions, Westminster Avenue is situated at -grade within the PE ROWand contains median landscaped with grass and several tall. mature trees. With the implementation of the LPA, Westminster Avenue would be maintained atgrade through the PE ROWwith the streetcar alignment crossing via a new single span tied -arch bridge crossing up to 220feet in length with a maximum deck height of 23 feet. Although no bridge design was prepared for the Westminster Avenue Bridge as part of the 2015 EA, for Visual analysis purposes, the 2015 EAdepicted the bridge in a conceptual photo simulation as a single span arched bridge. Figure 2 illustrates the existing at -grade crossing and proposed conditions under the approved 2015 LPA, with a single span tied -arch bridge. As an outcome of advancing the projectdesign and performing value engineering for the LPA, OCTA determined that more efficient bridge design options could be implemented at the WestminsterAvenue location. This resulted in the selection of concrete box girder bridge design thatis more co nve ntionally used in highwayand light-rail/streetcar corridors throughout southern California. The modified bridge design would include a two span concrete box girder bridge structure, as depicted in Figure 3, which would have similar dimensions for deck height and total length as compared to the conceptual bridge structure depicted in the 2015 EA. The main differences between the previously -depicted bridge and the currentbridge type include the elimination of the arches and hangers in the bridge's superstructure, which would increase the visibilityof the catenarywires, and the addition of single bent(pier support) near the center of the bridge. As shown in Figure 3, the modified bridge's appearance within the PE ROWwould be similar to what was previously shown for the bridge in terms of scale. Additionally, based on the surrounding Moderate Lowto Moderatevisualquality,the minor modifications would notoccur within an area that is highlysensitive to Visual change. Similar to the bridge concept depicted in the 2015 EA, the existing mature trees along Westminster Avenue would screen/buffer views of the bridge from adjacent vehicular and pedestrian traffic. Although the bridge would be Visible to residences south of Westminster Avenue and motorists driving along Westminster Avenue, the visual qualityof the area is urban in nature such thatthe bridge's addition would have no adverse affect/no significant impact. 31 Page