Memorandum

City of Lawrence

Department of Public Works

TO:	Chuck Soules
FROM:	Matt Bond
CC:	David L. Corliss, Diane Stoddard, Cynthia Wagner, David Cronin
Date:	October 8, 2012
RE:	October 16, 2012 Agenda Item Maple Street Pump Station, 6^th & Maple, Project No. PW1133 Engineering Services for Stormwater Improvements

Please include the following item on the City Commission agenda for consideration at the October 16, 2012 meeting:

Project Background.  The North Lawrence Drainage Study (NLDS) was received by the Lawrence City Commission in January 2006.  Upgrading the pump station on Maple Street in North Lawrence was one of the recommendations of the NLDS.  It also detailed the upgrading of the storm sewer infrastructure both up and downstream of the pump station.  In November 2008 the community overwhelmingly supported a 0.3% sales tax for infrastructure improvements.  The City began collecting sales tax funds in April 2009.  The Maple Street Pump Station was specifically designated to use this revenue source.  In preparation for the construction of the pump station, the parcels adjacent to the existing pump station were purchased in July 2010.  The design team of Bartlett & West Engineers & CDM Smith was chosen after receiving qualification statements for engineering services for the design of the Maple Street Pump Station and corresponding storm sewer improvements.

Project Description.  The existing pump station is a converted sanitary sewer lift station with a maximum pumping capacity of approximately 38 cfs (cubic feet per second) and is grossly undersized for the amount of stormwater it experiences during rain events.  The area designated as "System 6", in the NLDS, contains roughly 192 acres and experiences localized flooding during significant rainfall events (see Attachment A).  The parcels to construct both the pump station and the wet well have already been acquired (see Attachment B). The NLDS recommends a pump station with a capacity of 305 cfs.  It should be noted that this recommendation was a cursory view of the needed capacity of the pump station.  A closer more detailed analysis needs to be completed to accurately size the necessary pump station and the corresponding piping and open channel network.  The storm sewer leading south from the pump station will include involvement from the US Army Corps of Engineers since it will pass through the Kansas River Levee.  In addition involvement with the Union Pacific Railroad will be necessary since the new line will travel under the railroad tracks.  The construction of this project will also involve the temporary disruption of traffic in areas adjacent to storm sewer pipe installation. 

Project Funding.  The NLDS estimated the construction cost for this project at $4.279 million.  Due to the complexity of the hydrologic and hydraulic computer models necessary to accurately model the watershed, design is estimated to take nine months to a year to complete.  This would result in the completion of design plans near the end of 2013.  The bid date would be set within a few months of the completion of the construction plans. This project is being funded with the Sales Tax Revenue. 

Action Request.  If appropriate, Public Works staff requests the approval of an engineering services agreement with Bartlett & West for a detailed hydrologic and hydraulic preliminary engineering report for "System 6" of the NLDS in the amount of $40,740.  The results obtained from the preliminary report will help to refine the scope of services for the upcoming design contract.