Orange County Branch Newsletter
Younger Member Forum
YMF - Haster Basin Construction Site Tour March 2013
By: Remi Candaele
Boots, safety vests, hard hats, and safety glasses on, twenty fellow YMFers could not spend a better afternoon outside (sunny and 86◦F) touring the Haster Basin Retarding Basin, Pump Station, and Recreational Field construction site. A majority of the parties involved in the different phases of the project were present during the tour, which facilitated the group’s understanding of the dynamics of the project. Among the powers at play present on this afternoon of March 1, 2013, the Board of OC YMF acknowledged the contractor (Shimmick Construction), the resident engineer (AECOM), the designers (AKM Consulting Engineers and Schmidt Design Group), and the owner (Orange County Flood Control District). The Board of OC YMF would like to join its members to thank Kasey Nielsen (OC Public Works) and Travis Olson (Shimmick Construction) for the opportunity to tour the site and for their dynamic and insightful interaction with the group.
The project is located within the limits of the City of Garden Grove, on a 21.2-acre property owned and operated by the Orange County Flood Control District. Before becoming a retarding basin, the property was formerly a sand and gravel quarry. The former retarding basin is currently being retrofitted to improve flood control protection of the downstream communities, as part of a larger improvement plan of the East Garden Grove – Wintersburg Channel.
Construction of the project was initiated in July 2012. Eight months after the beginning of construction, a few of the tour highlights included:
- The local groundwater seasonally fluctuates between 15 feet and 20 feet above the invert of the proposed basin, constituting a challenge during construction. Travis Olson pointed out several wells used to lower the water table below the finished invert of the basin. Structural elements of the foundation of the 460-cfs pump station notably required extensive well work for the concrete to reach its optimal compressive strength.
- The basin is currently placed in a series of flood control facilities and excavation of the basin occurred during the winter season, suitable for larger storms. The contractor indicated how the crew manages to divert dry-weather flows around the construction site using temporary gravity-drained channels. Kasey Nielsen identified that upstream flood control facilities were operated to retain all storm flows during this winter season.
- Kasey showcased the 700 linear feet of triple barrel reinforced concrete box (RCB) that were installed below-ground, above which soccer fields and a recreational area will emerge at completion of the project. At the outlet of the triple barrel RCB, YMFers were informed on the specifics of the headwall and wingwall.
- The presenters emphasized on the importance of the environmental process, which was performed in a proactive and comprehensive manner to inform the local community of the benefits of the project. The pump station will notably be installed in a building of local architectural features.
For additional information regarding the project, please check out the article published on the ASCE website by James Volz, PE. Link: http://www.asceoc.org/index.php/newsletter/article/agency_spotlight_haster_retarding_basin_and_pump_station
After the technical tour, the YMF group concluded the warm afternoon with a well-deserved happy hour at Alcatraz Brewing Co. in Orange. The happy hour was, not only the occasion to network and exchange on the respective engineering projects YMFers are currently involved with, but also a fun and convivial way to commence the weekend!