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HomeMy WebLinkAbout10/10/2006 Blue Sheet Barnett Linear Park Update TOWN COUNCIL MEETING INFORMATION TOWN OF MARANA MEETING DATE: October 10, 2006 AGENDA ITEM: D.3 TO: MAYOR AND COUNCIL FROM: James R. DeGrood, P.E. Assistant Town Manager SUBJECT Presentation: Barnett Linear Park Update DISCUSSION In July 2005, staff presented the recommendations of the Design Concept Report (DCR) for the Barnett Linear Park project, which collects floodwater concentrating at the 1-10 Frontage Road and surrounding properties in the Town Core. In this area, 6 multi-barrel box culverts pass beneath the Interstate and discharge into the eastbound frontage road. This study estimated that approximately 6000 cubic feet per second of flow may cross the freeway at this location, representing a sizable flooding problem. In the past, flows from these culverts have caused flooding of the elementary and junior high school campuses, as well as homes along Grier Road. In addition to the existing flood risks, future commercial and residential development within the Town Core area will be subject to this same flooding source, requiring expensive and difficult flood control improvements. At the time the Northwest Marana Area Plan was developed, this flooding problem was identified, and the Barnett Linear Park was proposed to collect and carry the floodwater to the Santa Cruz River. The Barnett Road alignment was selected for the channel, as it was the least heavily developed corridor for the channel. A preliminary feasibility report was done at that time by TetraTech, demonstrating the viability of the concept. The Town then hired AMEC Earth and Environment to prepare a DCR in order to further develop the plan. AMEC fully studied the hydrology, performed environmental studies, and identified 3 alternatives for collecting the flow from the culverts beneath Interstate 10. The preferred option was to build a new, deepened culvert beneath both the railroad and interstate, directly feeding into the Barnett Linear Park. Since that time staff has been in contact with both the Union Pacific Railroad and the Arizona Department of Transportation on the feasibility of the preferred option. Union Pacific Railroad (UP) The Union Pacific Railroad is proposing to double track the entire Sunset Route, from the Los Angeles Basin to EI Paso. In the course of this work, they will need to lengthen the existing culverts, where feasible, or replace the existing drainage structures with new structures when they add the second track through Marana. Two years ago, when the new siding for the Arizona Portland Cement plant was constructed, the UP found the existing culverts to be inadequate to extend. It is expected that several of the culverts draining to the Barnett Linear Park will need to be replaced, and we have requested that the UP consider replacing these culverts with a single, larger structure which is consistent with the preferred drainage plan. They have indicated a willingness to construct this structure, provided there are improvements downstream of the railroad which will convey the flow passing at the new drainage structure. The UP anticipates initiating the double track work next year, and completing nearly 300 miles of work by 2009. Arizona Department of Transportation (ADOT) ADOT is preparing to bid the next phase of Interstate 10 widening work, between Tangerine Road and the Pinal County line in the spring of 2007. The Town has reviewed the preferred drainage concept with ADOT, and we have requested that ADOT work with the Town in incorporating the proposed drainage structure in the upcoming work. While ADOT staff agree with the merits of proposed new drainage structure, they are concerned about how they work will be bid, given that they have shelf ready plans, and we do not yet have construction drawings available. They have, however, appropriated an additional $2 million to the project, using recently approved STAN funding authorized by the legislature in the last session. This additional funding is for the new drainage structure. Staff recognizes the urgency of the project, given the construction schedules of the UP and ADOT. Staff has authorized AMEC to begin construction drawings for the railroad and interstate crossings, and is negotiating the scope and cost for balance of the final design plans. RECOMMENDATION None required. SUGGESTED MOTION None required. -2-