Phase Three
The primary objective of the design is to show a reduced frequency of overflows of the combined sewer system to not more than seven events in a typical year. Approximately 70,000 square feet of green infrastructure storage was designed to provide 68,000 cubic feet of storage volume. A total of 44 green and gray structures will be built to capture almost 1.0 million gallons of wet weather runoff. As required in the consent decree, these improvements will result in 7 or fewer overflows at Outfall 069 during a typical year.
Rachel Morado Gardens is a large-scale storage facility with park-like attributes. The green infrastructure within the site includes pretreatment chambers, level spreaders, rain gardens and extended detention facilities to capture, treat and detain stormwater before entering into the combined sewer system. Green infrastructure captures stormwater runoff from streets and lawns and routes the flow to dense vegetation to encourage pollutants to settle and flow to infiltrate through the soils to reduce volume of water directed to Outfall 069.
In addition to reducing overflows, Rachel Morado is the central node of the Marlborough neighborhood, connecting a north/south boulevard with well-trafficked east/west thoroughfare and the lower Middle Blue basin with upper basin. The Rachel Morado site is ideally located for a physical neighborhood resource asccesible to all. The Paseo Boulevard is a historic boulevard with large trees lining the street. Green infrastructure was designed along the boulevard to route flow to the Rachel Morado Gardens. Shallow sod-turfed swales were designed for ease of maintenance, and rain gardens were designed at the intersections. The rain garden design had to keep with the historic boulevard design standards, so traditional plantings along with native plantings were incorporated to tie all the amenities together.