AHBE Lab has offered insights about the causes and effects of El Niño, both in its global influences and to our local Los Angeles environment. Yiran Wang’s 10 Things You Should Know About El Niño is a great primer about the global seasonal phenomena, while Gary Lai’s piece, Feast or Famine: Epic Drought to Epic El Niño connects the historical meteorological antecedents with this year’s El Niño.
Now for something more material and concrete: three AHBE projects have been under construction during the recent El Niño storms. Each project is designed with different features and techniques to incorporate sustainable stormwater best management practices (BMP), and showcase solutions faced while working during an unusually wet season here in Southern California:
Monrovia Station Streetscape
As an adjacent project to the Monrovia Gold Line Station, this project was to “demonstrate the healthy relationship between public space and sustainability” (Design Criteria Manual draft – 12/2013), alongside to provide infrastructure for stormwater management. The 1.3 miles of sidewalk around the station neighborhood are constructed from permeable pavers above Silva Cells.
Silva Cells are open-sided box frames engineered to keep soil available for street adjacent tree roots. Also, the street trees are planted in lowered curbside parkway swales that permit stormwater to flow into each planter directly from the street gutter using typical roadway grading. The storm water that flows into the parkways infiltrates into the ground, supporting native plants and street trees.
The biggest challenge faced during this season’s heavy rainstorms has been young, newly installed plants being washed away in the flow through parkways due to the intensity and length of the rainfall. Mitigation includes replacing washed out plants and temporarily blocking off the inlets from the street until the plants have stronger, more established roots. Though the Gold Line Station will not begin public operations until March 5, 2016, the streetscape has recently had its final landscape review.
Team members: Prime, IBI Design Group; Civil Engineer, CivilTec
Johnny Carson Park
A 17-acre public park in Burbank just north of the 210 Freeway, this project’s primary best management practice is the transformation of the Little Tujunga water channel that traverses the park from a concrete-lined creek into a destination water feature designed with an enhanced wildlife habitat, recreational access, and improved water quality.
During the storms, the concrete channel had been removed and had not yet been planted with restorative bank-stabilizing planting. This resulted in the erosion of the bottoms and sides of the exposed channel. Riparian stream bank plantings that are part of the design – such as brush mattresses – are being installed as quickly as is feasible in between storms to stabilize the creek sides. Brush mattresses are a living erosion control mat that is durable upon installation, and will increase in durability as it becomes rooted into the slopes of the stream. The park is scheduled to open in spring of 2016.
Team members: AHBE, Prime; California Watershed Engineering (CWE), Civil Engineers; Restoration Design Group, Stream Restoration
Torrance Storm Water Basins Enhancement Project
AHBE designers worked with the City of Torrance and civil engineers California Watershed Engineering (CWE) to cleanse and mitigate stormwater at 3 locations in the city.
The primary goal of the basins is to reduce exceedance of bacterial release into the Santa Monica Bay. The stormwater is retained, treated, and infiltrated into the ground, with excess released into the Santa Monica Bay. AHBE’s landscape design creates natural habitat, encouraging an increase of wildlife within the area. An outdoor classroom, positioned at the highest point of the area, provides an area to engage and educate local students as they learn about this stormwater treatment system and its benefits to the environment. The basins were opened to the public last autumn.
See the recent video Stormwater Basin Enhancement Program – Torrance CiriCABLE produced at the completion of the construction in September of 2015: