Res 2011-154 - Laserfiche WebLink

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ATTACHMENT A SCOPE OF SERVICES CHANNEL MODIFICATIONS AND GUADALUPE STREET BRIDGE REPLACEMENT Willow Springs Creek bisects the Victory Gardens neighborhood in San Marcos. Based on recently updated hydraulic modeling of the Willow Springs watershed and Willow Springs Creek, it is estimated that 74 homes currently reside in the regulatory floodplain within the study area. The scope of engineering services described in this document encompasses engineering planning and design initiatives necessary to complete previous planning and design work performed by Loomis Partners in support of flood control measures for Willow Springs Creek. Previous channel and bridge design investigations resulted in: a) determination of an optimal channel design from Ellis Street to McKie Street; and b) replacement of existing culverts at Guadalupe Street with a four -lane bridge. Design initiatives to date have included development of construction plans for channel improvements from Ellis to McKie including construction of a restored natural channel along the entire study reach. Subsequent planning initiatives by the City and further preliminary engineering by Loomis resulted in the decision to replace the culverts at Guadalupe with a bridge, to retain the existing concrete low flow channel upstream of Guadalupe, and to widen the proposed channel upstream of Guadalupe from 50 feet to 80 feet. The engineering and land surveying work described in this Scope of Services document represents project management, structural design, civil design, TxDOT permitting and coordination, Corps of Engineers permitting, and bid and construction phase services required to complete the bridge replacement project as described above. This contract document assumes the bridge will be bid separately from the adjacent channel improvements. CHANNEL MODIFICATIONS SCOPE OF SERVICES ENGINEERING DESIGN AND SURVEYING Project Management — Loomis will meet with City of San Marcos staff, City Council, and the Parks Department (4 meetings) to confirm channel improvement project planning elements. Loomis will continue to provide weekly project status reports to COSM project management staff. Loomis will organize, coordinate and present information on the project at public meetings (1 public meeting) as required by the City to assure the public remains informed and has the ability provide input. 2. Plan Preparation — For the purposes of this proposal, it is assumed the concrete low flow channel upstream of Guadalupe Street will remain in place. The primary flow conveyance channel upstream of Guadalupe will have a channel bottom 80 feet wide and sideslopes varying between 3:1 and 4:1. The channel downstream of Guadalupe will remain largely as previously