1. Jefferson High School Compton Creek Research Project UCLA and Los Angeles Waterkeeper Funded by the Environmental Protection Agency

2. WEEK 3 FEBRUARY 4, 2015

3. ANNOUNCEMENTS FIELD TRIP next week 3pm-6pm – Compton Creek – Look at what’s living in the Creek! (if it hasn’t been raining) – If it has been raining, we will also go walking along a natural stream  NEED SIGNED PERMISSION FORMS FROM EACH STUDENT!  Also, photo permission forms for UCLA website

4. Today Review from last time – urban vs non-urban Flooding and why our rivers are channelized Fun experiment about infiltration and streamflow Fun activity – make your own water filter

5. Review from last week Name at least 4 major differences between urban and non-urban areas, related to stormwater

6. OPEN SPACE Pervious surfaces Lots of vegetation Fewer pollutants Natural drainage network Most rain infiltrates into the soil Natural streams with vegetation URBAN Impervious surfaces Not much vegetation More pollutants Dense storm drain network (concentrated flows) Most rain flow directly to streams Concrete stream channels with little/no vegetation

7. Water Balance During a Storm Runoff Infiltration Between Storms Evapotranspiration Percolation and groundwater “recharge” Subsurface water flows slowly to streams

8. Today’s Experiment How do impervious surfaces affect flooding and runoff? How does the stream itself affect flooding and runoff?

9. Many streams and rivers in LA have been “channelized” WHY??

10. DECEMBER 9, 2014

11. SEPTEMBER 11, 2014

12. Many streams and rivers in LA have been “channelized” WHY?? Climate and geography in Los Angeles is unique Historically, many streams have flowed along different paths, creating problems for cities built nearby When water flows though a deep concrete channel, there is less friction and water moves faster than it does in shallow, vegetated pathways. This reduces flooding.

13. Video: https://www.youtube.com/watch?v=oRWrnlvVk Mo

14. SEPTEMBER 11, 2014

15. October 27, 2014

16. Hypotheses InfiltrationRunoffFlood Height Pervious Surfaceshigherlower Impervious Surfaceslowerhigher Vegetated Channelhigherlowerhigher Un-vegetated Channellowerhigherlower