San%20Diego

1
San Diegos Watershed and and Examination of Land
Cover in Relation to Pollution

• Tamera Ashcraft
• 30 November 2000

2
Outline

• Background on the San Diego River, Mission Bay
  and San Diego Bay
• Contamination and Habitat Destruction in the Bays
• The San Diego Watershed
• Urbanization of San Diego
• Summary

3
San Diego River History

• The San Diego River originally flowed into San
  Diego Bay
• Attempt to divert it in 1853 by the Army Corps of
  Engineers failed
• Another attempt in 1875 successful
• SD river drains 440 sq. miles

4
San Diego History

• 1870s - San Diego population was 2300
• Population in 1900 was 18,000
• The population doubled from 250,000 in 1940 to
  500,000 in 1948
• Sea World built

• In 1940 plan to fill in the marshes on the south
  side of Mission Bay to make an airport

5
Mission Bay

• Mission Bay drains approx 53 sq. miles
• Mission Bay water quality problems from bacterial
  contamination and from urban runoff
• High nutrient load
• High heavy metal content

• Implementing plans to limit non-point source
  pollution

6
San Diego Bay

• 415 sq. miles watershed drainage

• SD Bay has been contaminated by the power plant
  cooling, dammed tributaries, urban runoff, heavy
  metals from ships, and from a salt production
  plant

7
Area of Study

• An area of Southern California
• An area of increasing population growth
• An area where rare habitats Salt Marsh and
  Torrey Pines - are being threatened by
  urbanization and dredging

8
San Diego River

• This is the San Diego area
• Highlighted is the San Diego River
• It flows through a reservoir, a dam, and finally
  into Mission Bay

9
San Diego Watershed

• ¼ of the San Diego River watershed is used for
  urban or agricultural purposes
• The San Diego River deposits bacteria- and
  nutrient-rich water into the Bay

10
Urban San Diego County

• This is the portion of San Diego County that is
  Urban
• The salt marsh habitats have been nearly
  eliminated
• Salt marsh is important for cleansing the water
  and as habitat for marine invertebrates and
  juvenile fish
• San Diego Bay and Mission Bay have been damaged
  by dredging and habitat destruction

11
Land Use/Land Cover

• This is Land Use/ Land Cover Data for the San
  Diego Bay and Mission Bay areas
• The Urban area is highlighted in blue (all of the
  area is urban)

12
Land Use
Bays, lakes, reservoirs
Residential, commercial
Cropland, pasture, orchard
Urban
Shrub and Brush Rangeland
Evergreen Forest Land
Transitional Areas, Exposed Rock
Transportation, Community, Utility
13
Summary

• The San Diego River has been diverted from San
  Diego Bay into Mission Bay
• San Diegos population continues to grow
  urbanization is rampant
• This has resulted in a lot of habitat destruction
• What is the fate of the endangered species that
  depend on the contaminated water of the San Diego
  area and the salt marsh which is being destroyed?