The Brizzolara Creek Project provides stormwater management for runoff from a parking lot on the Cal Poly campus. It includes a boardwalk that offers students outdoor study and work spaces, as well as educational resources about water resources and pollution prevention. The design incorporates bioretention areas like bioswales, planter boxes, and a rain garden to capture and filter runoff. This helps reduce contaminants entering Brizzolara Creek and the larger watershed, protecting endangered steelhead trout and addressing regulatory limits. The system is designed to be resilient to California's Mediterranean climate and potential increased drought and intense rainfall due to climate change.

1. Seasonal Design
The Brizzolara Creek Project provides access
from Poly Canyon Village student housing
to the campus core, and treats storm-water
runoff from the H-16 parking lot. Existing
conditions incorporate minimal low impact
design and recreational uses. Brizzolara
Boardwalk offers students easier access,
shady outdoor work areas, and educational
resources. Due to California’s Mediterranean
climate, plants must be versatile and able to
deal with periods of prolonged drought...
... And several months of heavy rainfall.
During these months, the site captures runoff
and allows for it to infiltrate using multiple
Best Management Practices. In addition, the
bioretention also treats various contaminants
including: pathogens, suspended solids, and
agricultural nutrients. This rain also offers new
educational opportunities in water resources
and pollution prevention.
Pollution Prevention
The runoff from the H16 parking lot
drains into Brizzolara Creek which
is located at the south end of the site.
Brizzolara Creek is part of the San Luis
Obispo Creek Watershed, which
encompasses agricultural,
developed, and natural land,
all of which contribute unique
contaminants to storm-water runoff.
The Environmental Protection Agency
has imposed a Total Maximum Daily
Load for pathogens on the watershed
and the Steelhead Trout, which are
indigenous to the region, are listed as
endangered by the Endangered
Species Act. It is important to reduce
the pollutants that enter
the watershed wherever possible.
The runoff from the H16 parking
lot is susceptible to contamination
from both agricultural and urban
sources. The agricultural practices on
campus contribute pathogens and
nutrients (nitrogen and phosphorous)
from fertilizer and manure and
erosion from clearing foliage for
grazing land. Developed areas on
campus introduce oil, grease, soap,
toxic chemical, heavy metals, and
sediments. Our design provides many
opportunities for storm-water to
infiltrate and contaminants to settle
before entering Brizzolara Creek.
San Luis Obispo is classified as a
warm/wet climate, with low levels of
rainfall during summer months and
high levels during winter months.
Based on the EPA National
Stormwater Calculator, in the next 35
years warm/wet climates will
experience longer periods of
drought and more intense and
infrequent rainfall events. Our BMPs
Site Hydrology
The primary drainage plan on H16
is for storm-water to collect in a
concrete basin and discharge to
Brizzolara Creek through a steel culvert
pipe. At a 5% slope, water flows over
the impervious parking area, hits the
curb along the southern boundary
of the parking lot, and enters the
detention basin through a curb cut.
There is one drain northeast along the
curb, but the drain is only 12 inches
wide and is clogged with debris. Since
the detention pond is at the lowest
elevation, all surface runoff is directed
to the concrete basin. The concrete
detention system was not designed to
detain large quantities of water so
there is flooding that occurs along the
southern end of the site. In addition,
the high velocity discharge into
Brizzolara Creek is eroding the creek
bed.
Proposed Design
Our design includes bio-
swales, planter boxes, and a
rain garden that will detain
water during larger storm
events. The swales and planter
boxes will capture
approximately 33% (0.32 acre-
ft) of the rainwater before it
reaches the southernmost
edge of the site. The biological
components will remove
primary contaminants
from the water before they
reach the rain garden, where
the majority of the water will be
detained. Here, the suspended
solids will be settled out, with
several of the contaminants
being treated using local
vegetation. The water will then
either infiltrate or enter into a
vertical pipe down to Brizzolara
Creek.
Brizzolara Boardwalk registration number : D46
Agricultural areas in San Luis Obispo
watershed
Developed areas in San Luis Obispo
watershed
our prepared to handle these
climate changes by providing
bioretention areas to capture large
quantities of water. In addition, the
plants in our BMPs can handle
drought as well as inundation. Our
project also has 60% tree cover to
reduce the heat island effect and
minimize the impact on climate
change.
Climate Change Resiliency
Average rainfall in San Luis Obispo 2014 Average temperature San Luis Obispo 2014
EPA National Stormwater Calculator