Jed Smith Green Street
Jed Smith Drive was converted to a “green street” that reduces stormwater runoff and pollutant transport, and enhances the pedestrian experience. Rain gardens, porous pavement parking, and new walkways have been installed on both sides of the street.
Porous Pavement
On both sides of the street, angled parking stalls were removed and replaced with porous pavement parallel parking. At this site, the porous pavement is constructed using a special concrete mix with a very open internal structure (see diagram and photo below). You can literally pour water through it from a bucket as shown in this video. Below the porous pavement, runoff is stored and allowed to percolate into the soil.
Rain Gardens
On the east side of Jed Smith Drive, an existing lawn and drainage ditch were replaced with three interconnected rain gardens. The gardens were separated to preserve the existing trees because their canopy is valuable for reducing urban heat build-up and encouraging pedestrian and bicycle use. The rain garden on the west side receives runoff from the parking lot between the street and the parking structure. The existing storm drains were capped so that the flow would go into the garden. The north end of the lot drains into a cobble trench. Water flows underground through the cobbles and surfaces in the garden. In all three rain gardens, runoff is collected and infiltrated into the native soil (see diagram below). During large storms, runoff that cannot be taken up by the soil overflows into the campus drain system and is conveyed to the American River.
Want more details? https://www.owp.csus.edu/csus-lid/
Existing Drainage
The existing drainage could not be removed because the system is still utilized (though in a lesser capacity). Engineers needed to plan ahead to build around the existing system.
Saving the Trees
Large trees are valuable parts of the urban landscape. At this site, the rain garden was divided into three cells that were connected by pipes. To protect tree roots, the connecting pipes were laid under the new sidewalk and joined with junction boxes (the green lines in the photo are the pipes). The trees at this site are compatible with infiltrating BMPs near their roots. Some trees, however, cannot tolerate standing water or the large volume of water that accompanies an infiltrating BMP. Before siting an infiltrating bioswale, rain garden, or bioretention planter near mature trees, consult an arborist.
Integrating Porous Pavement into an Existing Street
Installing porous pavement in an existing street is not a simple matter of ripping up the asphalt and installing a new concrete surface. Excessive water can weaken pavement foundations (the subgrade). To prevent water from migrating underneath the asphalt from the porous pavement in this project, a concrete wall was installed 18 inches deep and flush with the pavement surface (see photo below). This directed the infiltrating water downward below the existing asphalt subgrade.
Additional Concerns
After space was allocated for tree roots and parallel parking, the resulting vehicle lanes were 11 feet wide. Although this is not unusually narrow for urban streets, delivery truck and bus drivers expressed concern about safety, especially with parallel parking on both sides of the street. To address these concerns, the parallel parking on the east side has been closed.
These are the plants at this BMP Site:
Featured Plant
California Coffee Berry (Rhamnus Californica)
Rhamnus Californica: Image by: Evangele19 (Creative Commons Attribution-Share Alike 3.0 Unported)
Berkeley Sedge (Carex Divulsa)
Blue Eyed Grass (Sisyrinchium Bellum)
Deer Grass (Muhlenbergia Rigens)
Douglas Iris (Iris Douglasiana)
Feather Reed Grass (Calamagrostis x Acutiflora 'Karl Floerster')
Indian Hawthorn (Rhaphiolepis Indica)
Lomandra (Lomandra Longfolia 'Breeze')
Maritime Ceanothus (Ceanothus Maritimus 'Valley Violet')
Spreading Rush (Juncus Patens 'Elk Blue')
Want more details? https://www.owp.csus.edu/csus-lid/
Porous Pavement
On both sides of the street, angled parking stalls were removed and replaced with porous pavement parallel parking. At this site, the porous pavement is constructed using a special concrete mix with a very open internal structure (see diagram and photo below). You can literally pour water through it from a bucket as shown in this video. Below the porous pavement, runoff is stored and allowed to percolate into the soil.
Rain Gardens
On the east side of Jed Smith Drive, an existing lawn and drainage ditch were replaced with three interconnected rain gardens. The gardens were separated to preserve the existing trees because their canopy is valuable for reducing urban heat build-up and encouraging pedestrian and bicycle use. The rain garden on the west side receives runoff from the parking lot between the street and the parking structure. The existing storm drains were capped so that the flow would go into the garden. The north end of the lot drains into a cobble trench. Water flows underground through the cobbles and surfaces in the garden. In all three rain gardens, runoff is collected and infiltrated into the native soil (see diagram below). During large storms, runoff that cannot be taken up by the soil overflows into the campus drain system and is conveyed to the American River.
Want more details? https://www.owp.csus.edu/csus-lid/
Existing Drainage
The existing drainage could not be removed because the system is still utilized (though in a lesser capacity). Engineers needed to plan ahead to build around the existing system.
Saving the Trees
Large trees are valuable parts of the urban landscape. At this site, the rain garden was divided into three cells that were connected by pipes. To protect tree roots, the connecting pipes were laid under the new sidewalk and joined with junction boxes (the green lines in the photo are the pipes). The trees at this site are compatible with infiltrating BMPs near their roots. Some trees, however, cannot tolerate standing water or the large volume of water that accompanies an infiltrating BMP. Before siting an infiltrating bioswale, rain garden, or bioretention planter near mature trees, consult an arborist.
Integrating Porous Pavement into an Existing Street
Installing porous pavement in an existing street is not a simple matter of ripping up the asphalt and installing a new concrete surface. Excessive water can weaken pavement foundations (the subgrade). To prevent water from migrating underneath the asphalt from the porous pavement in this project, a concrete wall was installed 18 inches deep and flush with the pavement surface (see photo below). This directed the infiltrating water downward below the existing asphalt subgrade.
Additional Concerns
After space was allocated for tree roots and parallel parking, the resulting vehicle lanes were 11 feet wide. Although this is not unusually narrow for urban streets, delivery truck and bus drivers expressed concern about safety, especially with parallel parking on both sides of the street. To address these concerns, the parallel parking on the east side has been closed.
These are the plants at this BMP Site:
Featured Plant
California Coffee Berry (Rhamnus Californica)
Rhamnus Californica: Image by: Evangele19 (Creative Commons Attribution-Share Alike 3.0 Unported)
Berkeley Sedge (Carex Divulsa)
Blue Eyed Grass (Sisyrinchium Bellum)
Deer Grass (Muhlenbergia Rigens)
Douglas Iris (Iris Douglasiana)
Feather Reed Grass (Calamagrostis x Acutiflora 'Karl Floerster')
Indian Hawthorn (Rhaphiolepis Indica)
Lomandra (Lomandra Longfolia 'Breeze')
Maritime Ceanothus (Ceanothus Maritimus 'Valley Violet')
Spreading Rush (Juncus Patens 'Elk Blue')
Want more details? https://www.owp.csus.edu/csus-lid/