Malibu Lumber Yard

Challenge

Situated adjacent to the Malibu Creek watershed terminus, the combined program and project site presented a tremendous challenge to address water quality requirements in an evolving regulatory environment. The City of Malibu had enacted a moratorium on new development  to solve wastewater and runoff water quality issues in critical habitat areas. Though Malibu Lumber Yard was considered a redevelopment, it was held to much higher standards on water management because of the regulatory environment during the design, entitlement, and construction of the project.

Furthermore, Malibu Lumber Yard was developed in partnership with the City of Malibu following a rigorous RPF process. The sustainable design and water management concepts proposed were a requirement to be an eligible partner and ultimately resulted in the development team winning the project. The City of Malibu has extensive requirements for treating wastewater and stormwater and operates its own local Coastal Program under the supervision of the California Coastal Commission.

Solution

To meet the various regulatory requirements, the team set out to establish Malibu Lumber Yard as a fully self-contained water management project. This involved incorporating innovative water conservation measures, including a low water-use plant palette; low-flow faucets, toilets, and waterless urinals; and the use of municipal reclaimed water. All project wastewater is treated using an advanced onsite wastewater treatment system. Stormwater and site runoff are captured and filtered in a system of bioswales and gravel filtration beds under paving before being discharged to the municipal system.

While the treated water is not used on-site, the wastewater is being used to recharge the adjacent Legacy Park groundwater as a temporary condition. In the future, the plan is to use the treated wastewater to supplement Legacy Park’s irrigation and water treatment programs and redirect all treated stormwater that is currently feeding into the municipal system to the water treatment lagoons at Legacy Park.

• Precast concrete pavers, planters, permeable asphalt, and a courtyard deck built over gravel beds reduce the impervious surface area of the site by 75%, even with the additional new building footprint.
• A system of two bioswales totaling 9,990 sf and 45,000 sf of 12-in thick gravel beds filter runoff from the roof, deck, and parking areas before it is discharged to the municipal system. 
• Rainwater falling on the rooftop is directed through a roof drain to under the courtyard deck and into the bioswale.
• Building wastewater is processed in an on-site biomembrane reactor water treatment system.
• Plants selected for the site include California native plants, succulents, and other low and extremely low water-use plants that require 1/3 as much water as a typical plant palette.
• The irrigation system tailors water supply to each hydrozone to ensure that plants receive only as much water as they need to grow in a healthy manner.
• 100% of water used for irrigation is reclaimed water purchased from the Las Virgines Municipal Water District.
• Light-colored permeable pavers, natural-colored permeable concrete, and planted areas reduce the urban heat island effect and the energy needed for building air-conditioning.

• The permeable paving was more costly than traditional asphalt or cast in place concrete ($140,000 - 70,000 sf at an additional $2 per sf), which was offset by the savings of what would a conventional drainage system and CDS unit would have cost (approximately $150,000).
• The use of reclaimed water reduced irrigation cost by 25%. The cost of potable water in Malibu is $1.58 per unit and reclaimed water is $1.22 as of November 23, 2010.
• Additional irrigation cost savings of $332 per year are attributed to low water use plant material selected for the site, which lowered annual irrigation needs by 203,000 gallons or 66%.

• An initial attempt to use decomposed granite as a permeable parking surface failed as dust and mud were too difficult to contend with and the center’s retailers were getting too many complaints from Malibu residents. It had to be replaced with a combination of permeable interlocking pavers and permeable concrete.
• Some sustainable strategies were not acceptable for the fire department in this highly fire-prone area. Green roofs and green walls were rejected because vines or other plantings directly on building walls are considered fuel for wildfires and are prohibited due to the dry climate and adjacency of the site to the Santa Monica Mountains, an extremely fire-prone zone. The green roof concept was replaced with high albedo roofing material.

Project Team

Co-Developers: Richard Sperber and Richard Weintraub
Landscape Architect: ValleyCrest Design Group (now BrightView)
Landscape Contractor: ValleyCrest Landscape Development, Inc. (now BrightView)
Executive Architect: RTK Architecture
General Contractor: Matt Construction
Lighting Design: Lightvision Architectural Lighting Design
Civil Engineering: Psomas
Structural Engineering: Specialty Structural Services, Inc.

Role of the Landscape Architect

The landscape architect provided landscape design-build services for softscape, hardscape, and irrigation work. From concept and theme development through installation, the approach emphasized environmental responsibility, water conservation, and innovative on-site stormwater and wastewater management.