FROM: Mark A. Young, LRWWU Executive Director
Nicolás H. Bosonetto, P.E., City Engineer (Interim)
City Council Motion 11.9. (7/25/17) – C. Leary – Request City Mgr. provide an update regarding the flooding/drainage issues on Alcott Street and Douglas Road.
City Council Motion 8.7 C. Samaras/C. Leahy – Request City Manager provide an update regarding the costs of all Infrastructure Improvements (Ie. Water/Sewer Upgrades); Include the costs associated with the replication of all the open space areas pursuant to article 97.
There have been a number of wet weather events since the installation of the level sensor with the only overflow occurring during the rain event of Tuesday, July 18th. The surcharge was approximately 1.5 feet above the street level and lasted for about 25 minutes. (see attached chart) This very intense rainstorm also caused other surcharge issues in the City.Currently sewer backups in the Douglas/Winward Road/Alcott Street area are minimal, do not occur on a regular basis, and occur only during very intense downpours.
With the LHS at Cawley project, additional stormwater and sewage will increase the volume flowing into the Oakland Trunk Sewer Line. It is recommended that further studies and engineering be conducted in conjunction with the LHS project to determine the exact requirements and costs of mitigation strategies. Preliminarily, it is believed that a storm water storage/retainage system could be constructed under the Cawley Parking lot to attenuate strong storm events and relieve the surcharge problem. An approximate cost of such a project would be about $5 Million.
As part of the design for a new high school at the Cawley site, Perkins|Eastman is aware that underground retainage systems will be needed to address issues related to the needs of a new high school. Perkins|Eastman will work with Mark Young and the City Engineer to during design phases to incorporate and address wastewater and water needs beyond the boundaries of the new high school site.
Infrastructure site improvements are reimbursable up to 8% of the total construction costs
Flow test performed on Rogers Street and the Cawley feed main indicated flow restrictions most likely caused by the poor condition of the existing 6” cast iron mains.
The estimated costs to replace the Rogers Street main is $700,000.00 it is recommended that when funding is available the 6” Rogers Street water main be replaced with a 12” main. To ensure adequate water flow to a new high school on the Cawley site replacement of the existing water main to Cawley with a 12” main is an estimated cost of $600,000.00.
For your consideration, the Department of Public Works has compiled budget estimates to replicate Carvalho Field at Cawley Stadium and a full renovation/construction at the proposed Manning Field Complex located at 303 Boston Road.
Total Costs: $1,970,000