manzanita village: a case study turning lemons into lemonade jennifer j. bitting, pe central coast water board
manzanita village: a case studyturning lemons into lemonade
jennifer j. bitting, pecentral coast water board
outline
• what is manzanita village?• project setting• project history• water quality results• beneficial outcomes • sustainabliliy review• lessons learned
manzanita village: ucsb housing complex
• 6 acre site• eleven 3-story
buildings• six 4-story
buildings• houses 800
students• opened
september 2002
project setting
• mediterranean climate• marine terrace deposits
on sisquoc shale• clay subsoil• degraded grassland and
vernal pool landscape• bordered by the pacific
ocean and campus lagoon
original design
• traditional underground storm sewer system
• buildings too close to vernal pools
no treatment - discharge of phosphorus and nitrate polluted water to the beach, surfer-filled waters?
no volume reduction
increase rate of bluff erosion
habitat for endangered species
designed to meet federal wetland guidelines but not state requirements
plans needed to be modified – ecology professors and research students used the opportunity to recommend bioswales and wetlands to aid in site drainage
new design
75% of the project area flows through biofiltration systems
1300 linear feel of swales
• 4 swale systems with 43 bioswale basins
• 8 experimental plant palettes
2 stormwater wetlands
1 vernal marsh
3 vernal pools
new designbioswales
• 8 experimental plant palettes using:
• 3 rushes:
• juncus mexicanus
• juncus patens
• juncus phaeocephalus
• 3 sedges:
• carex praegracilis
• eleocharis macrostachya
• scirpus maritimus
• single species basins
• rush basins
• sedge basins
• rush and sedge basins
• control basins
bioswale planting september 2002 bioswale vegetated
august 2003
results
water quality results
• 99.5% reduction in nitrates
• 81.8% reduction in phosphates
beneficial outcomes
• potable water vs. reclaimed water
• bioswale clippings make nutrient rich mulch for university landscaping
bioswales watered with reclaimed water grew faster during the plant establishment phase and consequently were able to treat storm water more effectively.
using reclaimed water reduced the use of potable water and reduced the water bill.
sustainability review
• environment– provides habitat for endangered species– reduces pollutants discharged to campus lagoon– does not contribute to bluff erosion
• economics– reduces $ spent on mulch– reduces potable water bill (used reclaimed water for plant
establishment)– takes the place of ordinary landscaping (not irrigated)– does not contribute to loss of real estate (bluff erosion)– less $ spent on underground storm sewer installation and maintenance
• social– boardwalks, viewing terraces and bike trails control traffic and restrict
access to the fragile habitat– entirely wheelchair accessible– educational signs inform students about animal and habitat sensitivity– public health benefit: water is treated before discharge to the beach
and ocean
lessons learned
• design low impact development into the project in the first place!– design cost savings not realized; project
had to be designed twice.
• utilize design change opportunities to make projects more sustainable!
• take advantage of mistakes– potable vs. reclaimed water
sources & more info
• more info:– ucsb cheadle center for biodiversity and
ecological restoration (805) 893-2401 http://ccber.lifesci.ucsb.edu/
• sources:– http://dailynexus.com– http://sustainability.ucsb.edu– http://www.coastalconference.org