Transcript Stormwater and Low-Impact Development in San Diego, CA

Stormwater and Low-Impact
Development in San Diego, CA
Mitchel J. Bartolo
November 24, 2015
Source: City of San Diego
Why We Care #1: Water Cycle
Precipitation
Source: Minnesota Pollution Control Agency
Time hrs)
Infiltration
Subsurface storage
Overland flow
Streamflow
Source: City of San Diego
Why We Care #2: Pollution
Bacteria/Viruses
Oil and Grease
Sediment/Turbidity
Metals
Nutrients (N, P)
Organics
Pesticides
Source: City of San Diego, NBC San Diego
Low-Impact Development (LID)
• LID reduces imperviousness by replicating natural
hydrology
– Addresses both flow and pollution issues
• Parking lots, buildings, sidewalks  permeable
pavement, green roofs, vegetated swales,
bioretention basins
LID in San Diego
Study Area-Watershed Analysis
•
Permebale
pavement,
bioswales, rain
barrels
•
•
“Green Street”
Pilot: bacteria
Vegetated
swales and
bioretention
basins
Evaluating LID Effectiveness
A) Flood Response
– No USGS gage in this watershed
– Precipitation varies: hard to compare
B) Pollution
– San Diego SWPP Program
– Yearly Monitoring Data
Stormwater Conveyance System
DW0275
Pollution Monitoring Data
/100ml
or CFU
MPN
/100ml
MPN
8000
120000
7000
100000
6000
DW0275
DW0275
80000
5000
Fecal Coliform
Enterococcus
4000
60000
3000
40000
2000
20000
1000
00
2007 2008
2008 2009
2009 2010
2010 2011
2007
Year
Year
2012
2012 2013
2013 2014
2014
To-Do List
• Sort out GIS layer acquisition w/ City of
SD
• Analyze water quality data for each site
• Quanitify flow impacts with HEC-HMS
model
– Impervious values, before and after LID
– Compare responses to a fixed storm event
Questions?