Land Use
The way land is developed and used impacts the quality and quantity of stormwater. Different land use types impact stormwater in different ways. A large regional shopping mall and its associated parking lot have more impermeable surfaces than a typical single family residence and the quantity of surface stormwater is much greater as water is unable to permeate into the soil. During heavy rains, surface stormwater collects rapidly causing erosion, damage to the vegetation, and a rapid increase in stream water flow. Land uses also impact the quality of the stormwater. Golf Course greens and major roadways will contaminate stormwater with vehicular oils, pesticides and herbicides.
The following table, created from King County data, accompanies the Thornton Creek Land Use Map and summarizes the dominant land uses in the watershed. Following the table is a brief description of the land use categories.
|
Land Use Category |
Area in Sq. Ft |
Total Acres |
Percentage of Total |
|
Church |
3106851 |
71 |
1% |
|
Golf Course |
6993871 |
161 |
2% |
|
Government Service |
439400 |
10 |
Less than 1% |
|
Hospital |
4919017 |
113 |
1.6% |
|
Industrial |
118062 |
3 |
Less than 1% |
|
Mixed Use |
450892 |
10 |
1.5% |
|
Multi-Family |
9200364. |
211 |
3% |
|
Office |
3867412 |
89 |
Less than 1% |
|
Other Housing |
1645401 |
38 |
Less than 1% |
|
Park/Playground |
4844692 |
111 |
1.5% |
|
Parking |
1787180 |
41 |
Less than 1% |
|
Recreation/Entertainment |
1286498 |
321 |
4% |
|
Retail/Service |
13242503 |
304 |
4% |
|
ROW |
|
1671 |
23% |
|
School/Daycare |
13208478 |
303 |
4% |
|
Single Family |
159834342 |
3669 |
50.5% |
|
Terminal/Warehouse |
1412074. |
32 |
Less than 1% |
|
Utility |
1506495 |
35 |
Less than 1% |
|
Vacant |
10671835 |
245 |
3% |
|
Other |
5040245 |
116 |
2% |
|
|
|
|
|
|
|
|
|
|
|
Total Acres |
7263 |
|
|
Church: tax exempt building used religious; may provide community gathering
Golf Course: primarily outdoor area for playing golf
Government Service: includes post offices and other government related buildings
Hospital: regional facility for health related care
Industrial: includes industrial areas for production, storage, and distribution
Mixed Use: includes some form of housing with either retail sales/services or office uses
Multi-Family: duplex, triplex, town homes, or apartment buildings
Office: business offices
Other Housing: nursing homes, dormitories, or live-in care facilities
Park/Playground: public/private outdoor open space, playgrounds
Parking: parking lots or parking structures
Recreation/Entertainment: health clubs, other clubs, movie theaters
Retail/Service: retail sales and retail services
ROW: publicly utilized area for transportation or transportation related activities; includes roads, alleys, sidewalks, freeways, planting strips, and ditches.
School/Daycare: public or private facilities for education and/or childcare
Single Family: single family structure
Terminal/Warehouse: warehouse or transit terminals
Utility: public utilities such as transformers, substations
Vacant: undeveloped property
