What is an impervious surface?

Impervious surface means those disturbed or hard surfaced areas that either prevent or impede the natural entry of water into the soil. Rooftops, buildings, streets, parking lots, sidewalks, asphalt, concrete, other paving, driveways, patios, artificial turf and storage areas are all examples of impervious surfaces. These improvements effect natural infiltration, creates more runoff, increases the rate of runoff and alters runoff patterns of stormwater that drains from an area.

surface-run-off

Show All Answers

1. What is stormwater and why is it a problem?
2. What kinds of pollutants are found in stormwater?
3. Are sewers and storm drains the same thing?
4. What can you put down the storm drain?
5. What can residents do to help improve stormwater quality?
6. What is the National Pollutant Discharge Elimination System (NPDES) Stormwater Program?
7. What kinds of stormwater discharges are required to have NPDES stormwater permit coverage?
8. What is a Municipal Separate Storm Sewer System (MS4)?
9. Which MS4s are regulated by the Eastern Washington Phase II Municipal Stormwater Permit?
10. What happens if Yakima County does not comply with its NPDES stormwater discharge permit?
11. What is the stormwater utility?
12. Why does Yakima County need a stormwater utility?
13. What is the stormwater fee used for?
14. How will the stormwater management program benefit taxpayers, homeowners, etc.?
15. How are the regional stormwater utility service areas determined?
16. How is the stormwater fee calculated?
17. What is an impervious surface?
18. Is the utility fee just another tax?
19. No water runs off my property. Why am I being charged a stormwater fee?
20. What is meant by a "larger common plan of development or sale?"