- City of Cypress
- Flood Management Project of the Year
- Additional Files
- Additional Information
Myra 3 Stormwater Pump Station
- Project Location:
- Project Description:
Myra 3 Stormwater Pump Station project upgraded an existing 50 year old deficient pump station within the existing property, utilizing the original wet well. It constructed improvements to the existing wet well to bring it into compliance with the Hydraulic Institute Standards, improved the inlet drains, replaced all mechanical and electrical equipment, constructed a superstructure to house the mechanical and electrical equipment, and provided a standby generator to operate the pump station during commercial power outages. Two new pumps of 30 CFS capacity, along with the upstream in-line detention basin (currently under construction) will provide expected value 100-year flood protection to the tributary area that is in a sump condition south of Carbon Creek Channel, between Bloomfield Avenue and Denni Street.
- Project Justification:
The project had to be constructed at a very limited site, only 30 feet wide, between two single family residences, in a very high groundwater area. Therefore, maximum use of existing structures were incorporated into design to minimize the impact of dewatering on the adjacent structures. Because a large wet well with sufficient storage could not be constructed due to site limitation, the project design included an in-line detention basin. Additionally, in order to complete the pump station project during the dry season, the City purchased the long duration delivery items (pumps, motors, and variable frequency drives) prior to bidding the project for installation by the Contractor.
- Special Circumstances:
The City informed the residences impacted by the project prior to the start of construction, and incorporated their concerns into the project phasing and construction traffic control. The residents are elated that flooding problems that restricted from past inadequate facility have been eliminated.
- Project Attachments:
The project was completed with minimal change orders.
The City of Cypress, the Design Engineer/Construction Manager (AKM Consulting Engineers) and the Contractor worked as a team in completing the project with minimal impact on the residents.
- Award Citation::
The Myra 3 Stormwater Pump Station project upgraded a 50 year old facility to provide expected value 100-year flood protection to a 60 acre residential area south of Carbon Creek Channel between Bloomfield Avenue and Denni Street. In order to complete the project during the dry season, the City pre-purchased the long lead items prior to awarding the contract, for installation by the Construction Contractor.
- Suggested Award Summary:
The original pump station was over 50 years old. With the exception of the structure, it had reached the end of its useful life. It did not have the capacity to handle the peak flow of the expected value 100-year flood. In order to address these problems, the City formulated a multi-phase improvement project. The first phase upgraded the pump station. The second phase is constructing an in-line detention and upstream storm drain.
The original pump station sump structure was not replaced, but modified by replacing the influent storm drain and sump entrance, as well as replacing the existing sump top slab with a new reinforced concrete top slab. The upgrades included:
• New electric service to operate both pumps
• New high speed communications service
• Two (2) new variable frequency drive/bypass solid state motor controller operated, inverter duty, electric motor drive, 30 cfs axial flow pumps.
• New motor control center, including SCADA and an automatic transfer switch
• A 250 kW natural gas engine generator in a weather resistant, sound attenuated lockable enclosure to operate the pump station during commercial power outages
• Replacement of the influent storm drain with a 4.5 foot (w) by 4.5 foot (h) reinforced concrete box
• New trash rack structure
• New reinforced concrete block masonry/stucco pump station superstructure
• Site improvements
• Repairs to the two existing 30-inch diameter flap gates
• Removal and replacement of 30-inch diameter steel and reinforced concrete discharge pipes
• New 150 gpm capacity, 5 HP recessed impeller submersible sump pump and its 3-inch diameter stainless steel discharge pipe
• Temporary bypass operations
• Removal and replacement of existing improvements
• Site and other work
The project included the installation of bypass pumping systems to provide flood protection during the construction of the improvements. This work included the construction of temporary drains, pipes, and structures, and two 16 CFS capacity pumps.
In order to complete the project prior to the start of the wet season, the City of Cypress purchased the main Stormwater pumps, their electric motors, and variable frequency drives (VFDs) with bypass solid state motor controllers (SSMCs) separately from the construction contract for installation by the Contractor.