ASCE Los Angeles Section

Newbury Gateway Park - 2250 Michael Drive, Newbury Park, CA 91320 and on Michael Drive between Madrid and Newbury Road in Newbury Park, CA.

As a result of stormwater runoff from approximately 120 acres of tributary area, the intersection of Michael Drive and Newbury Road would often be subject to localized ponding.  The conventional solution of installing a storm drain system is not feasible at this time.  The City worked with the Conejo Recreation Park District (CRPD) to use a portion of its adjacent property to build a series of bioswales and biodetention basin as an interim solution to relieve the ponding and reduce storm water.

This project is a unique example of leadership with persistent ingenuity.  After extensive research, conventional solutions to stormwater overflows could not be implemented. Confronting the challenge, the design team sought a solution that involved a hybrid combination of conventional approaches to stormwater management and Best Management Practices.  This new vision also required more effort in outreach to other jurisdictions and stakeholders (residents).  The result is a beautiful working solution.

The easements for the construction and maintenance of the bioretention were approved by the CRPD Board on October 6, 2011.  The easement was structured so that the City maintains the bioretention easement on CRPD property. The City also conducted a public workshop to inform residents of the project.  Residents who attended the Public Workshop at the Newbury Park Library on November 29, 2011, expressed overall support for the project.
The American Public Works Association Ventura County Chapter has recognized the Project as the 2013 Environmental Project of the Year.  The American Society of Civil Engineers Santa Barbara - Ventura Branch has recognized the Project as the Ventura County Project of the Year.

Once a design solution was identified, the next challenge was engineering and construction, so that the solution is buildable and sustainable.  This would require retrofitting existing streetscape and landscape to fit the “green solution’s” plan.
First, the City converted the five (5) feet wide parkways along Michael Drive to a bioswale and widened the parkways on both sides another five (5) feet.  The new ten (10) feet wide parkway infiltration bioswales consists of a slotted curb, sub drain, rock layer and a low flow filter.  The sub drain system filters low flows and drains to the biodetention area.
The bioswales and bio-detention system is designed to temporarily hold part of the stormwater flow to facilitate infiltration into the ground and allow excess stormwater flow to more slowly enter the existing drainage system.  Additionally, it naturally treats stormwater runoff and pollutants similar to low-impact development practices. 
At the request of CRPD, the University of California, Davis plant list of drought-tolerant California native plants were incorporated into the design.  The landscape enhancement replaces approximately 13,000 SF of the park’s turf and is estimated to use 30 percent less water.
Construction began in November 2012.  The construction of the drainage system began at the downstream end or point of connection.  The original point of connection (POC) to the existing storm drain system originally consisted of a 36-inch concrete riser and a 30-inch reinforced concrete pipe to connect to the back of an existing catch basin.  Just after the start of construction, POC was redesigned to avert the newly found conflicts in construction.  During the construction of the redesigned POC system, an unknown and unmapped electrical service line was severed.  The repair to the electrical service line had to be completed before the construction resumed.  Despite the utility issues, the City successfully completed construction and opened the park for use in November 2013.

Leadership with persistent ingenuity led the design team to solve a difficult storm water problem with a combination of conventional storm water management techniques and Best Management Practices.  A well established partnership with another public agency allowed for the construction of beautiful and sustainable storm water solution that benefits both agencies and its constituents.

As a result of storm water runoff from approximately 120 acres of tributary area, the intersection of Michael Drive and Newbury Road would be subject to frequent localized ponding.  The original solution was to design and construct a series of new catch basins and storm drain pipes to connect to the existing storm drain system.  After further research, it was determined the existing downstream system did not have adequate capacity to handle the additional flows.  The design team turned to a hybrid solution that involved infiltration along the parkways and to the adjacent park area known as Newbury Gateway Park a Conejo Recreation Park District (CRPD) facility.

Throughout the new design, maintaining the aesthetics of the park was a top priority. To achieve both objectives, an innovative plan to construct a series of bioswales and bio-retention area was developed.  The plan included the following elements:

• Widening the parkways by five (5) feet with slotted curb openings and a geofabric-wrapped rock layer and sub-drain along Michael Drive.

• Interconnecting the subdrain system that filters and directs nuisance and low flows from the parkways to the bio-retention area.

• Building a landscaped bio-retention area with native drought tolerant plants at Newbury Gateway Park.

The CRPD accepted the City’s proposal to build a bio-retention area by granting an easement.  The terms of the easement specified that the City would maintain the bio-retention easement area and incorporate the University of California, Davis plant list of drought-tolerant California native plants.  The new landscape enhancement replaces approximately 13,000 SF of the park’s turf and is estimated to use 30 percent less water. Additionally, it naturally treats stormwater runoff and pollutants similar to low-impact development practices.  The project began construction in November 2012 and was opened to the public in November 2013.