The Work We Do
Green Infrastructure
Pervious Concrete
Pervious concrete allows stormwater to pass through pavement unlike traditional concrete where it runs off into the storm drain system. Below the surface, permeable rock captures pollutants and stores stormwater. Stormwater percolates into the ground and excess flows into the storm drain system through a perforated underdrain.
Articulated Concrete Blocks
Articulated concrete blocks are a pavement solution for areas with high runoff rates that prevents flooding by providing temporary water storage. The pavers are spaced so that stormwater can enter and accumulate inside the pavers’ arched chambers and in the permeable stone layer below where angular rocks create void spaces. The stored water percolates into the underlying soil or enters the storm drain system through a perforated underdrain.
Rainwater Harvesting
Rain barrels and tanks capture rainwater from rooftops and store it for non-potable uses later, like landscape irrigation. Rainwater harvesting reduces runoff and allows for the beneficial use of rainwater, conserving water. Built-in screens exclude mosquitos from the system.
Porous Asphalt
Porous asphalt allows stormwater to pass through the pavement, unlike traditional asphalt pavement where it runs off into the storm drain system. Below the surface, permeable layers capture pollutants and store stormwater. Stormwater percolates into the ground, and excess flows into the storm drain system through a perforated underdrain.
High Flow Rate Tree Well
High flow rate tree wells offer stormwater capture and treatment in locations where space is limited. The tree well filters consist of pre-manufactured concrete boxes filled with proprietary high flow rate media. Stormwater enters through the curb inlet and is filtered by the media and tree roots. Stormwater not used by the tree enters the storm drain system through a perforated underdrain.
Bioretention Tree Well with Trash Capture
Bioretention tree wells with integrated trash capture provide stormwater collection and treatment where space is limited and pedestrian access needs to be maintained. Stormwater enters through the trash capture inlet where debris is removed before biotreatment soil media in the bioretention area filter out pollutants. Stormwater not used by the tree percolates into the ground or enters the storm drain system through a perforated underdrain. This system was developed by the City of Fremont and is included as a standard detail for construction.
Underground Structural Cells
With underground structural cells, biotreatment soil media can be placed under paved surfaces that are designed for walking and vehicles. This allows tree roots to grow without damaging the pavement, while filtering and taking up stormwater. Stormwater not used by the trees percolates into the ground or enters the storm drain system through the underdrain.
Pervious Pavers
Pervious pavers allow stormwater to pass through the pavement unlike traditional concrete pavers where it runs off into the storm drain system. Below the surface, permeable layers capture pollutants and store stormwater. Stormwater percolates into the ground, and excess flows into the storm drain system through a perforated underdrain.
Permeable Pavers
Permeable pavers are concrete pavers installed with wider than normal joints to let stormwater pass through the joints between the pavers. Below the surface, permeable layers capture pollutants and store stormwater. Stormwater percolates into the ground, and excess flows into the storm drain system through a perforated underdrain.
Bioretention Area
Bioretention areas use plants and soil to slow and filter stormwater. Mimicking a natural process, bioretention areas allow for ponding of stormwater, filtering it through the planted area and through biotreatment soil media. The filtered water then percolates into the ground where it can replenish groundwater. Where site conditions don’t allow for this infiltration, a perforated underdrain sends the treated water to the storm drain system.
Bay-Friendly Principles
Creating a “Bay-Friendly” rated landscape, such as the Green Infrastructure Demonstration Project at Turner Court, means working with nature to reduce waste, while protecting watersheds and communities. The seven Bay-Friendly Principles include:
- Landscape Locally
- Landscape for Less to the Landfill
- Nurture the Soil
- Conserve Water
- Conserve Energy
- Protect Water and Air Quality
- Create Wildlife Habitat
Flow-Through Planter
Flow-through planters are self-contained systems that collect roof runoff and filter it as it percolates through the biotreatment soil media and permeable material below. Water not used by the plants enters the storm drain system through a perforated pipe at the bottom of the planter. Flow-through planters can be used to treat stormwater where infiltration is not desired, such as next to buildings, or where it is not possible due to poorly draining soils and steep slopes.
Horizontal Flow Biofiltration
Horizontal flow biofiltration systems, often referred to as “modular wetlands,” treat high flow rates in a small footprint. After passing through a trash screen, stormwater flows into the void space within the vault perimeter. Moving horizontally, the stormwater filters through biotreatment soil media, and then enters the storm drain system through the underdrain.