1. Assessment and Monitoring of the San Pedro Creek Flood Control Project Matthew Graul Arnie Thompson Wilson Yee Tim Brink

2. Purpose The purpose of this study was to extend the monitoring and assessment activities done by previous students and facilitate the collection of baseline data for the system.

3. Why do this study? Objective of the Flood Control Project was to restore channel shape and improve flood capacity of the creek Area provides critical habitat for two threatened and endangered species Newly planted restoration site (2 yrs old) Provide data to guide management practices and future restoration

4. Creek During Flood Event

5. Location of Study Area Southern most section of Pacifica, CA – Approx. 10mi. from San Francisco East of Hwy.1 bridge over San Pedro Creek Bordered by the –Lind Mar residential district to the N and E –San Pedro and Montarra Mountains to S –Pacific Ocean to the W

6. San Pedro Creek and Subwatersheds

7. Study Area View From the West

8. Overview of Project Site assessment (1 day) Cross Sections (4 days) Planimetric Map (1 day) Water Quality (1 day)

9. Study Area Cross Sections 1 2 3 4

11. Cross Section #1 204.6 feet in length Left bank is approx. 110 M SE of bridge Two stream sections – main channel & secondary channel

13. Cross Section #2 204.7 feet in length Starts approx. 300M SE of cross section #1 Two thalwegs, almost equal depth

15. Cross Section #4 22M in length Easy survey compared to other cross sections Upstream end of flood control project

16. San Pedro Creek Flood Control Project Plan View

17. Summary of Plan View Survey Surveyed roughly 300M of creek 90 survey points About 6 hrs of actual survey time Didn’t get as far as planned

18. List of Tools Used Laser rangefinder Tripod for laser Laser target Stadia rod Safety equipment we probably should have used…. Road cones Hardhats Suunto compasses (2) Waders Clipboard & pencil Walkie-Talkies 100M tape Orange vests

19. Taking a Measurement Two components of each survey point – range and azimuth Laser rangefinder –Ridiculously simple to use –Auto-corrects for sighting up-down angle –Displays horizontal & vertical distances –Accurate to better than 0.5 M Suunto compasses (2) –Foresight and backsight (when possible) –Accurate to 1-2 degrees

20. Procedure Matt was target when in line-of-sight Laser target mounted on stadia when line- of-sight obscured Foresight and backsight azimuth for accuracy Azimuth backsight not available in heavy vegetation

21. The Survey Surveyed 37 points each on left and right banks Surveyed fence line - a “significant feature” Three main tripod placements Closed out survey to within 1M –pretty satisfied with that level of accuracy

22. Recording the Data

23. Data Entry

24. Polar to Rectangular Conversion Survey points in polar – distance & azimuth Added 15.5° to convert from compass to map direction –R. Evans says declination is now about 15 °13’ Plotting on graph or in GIS requires X,Y coordinates Use trigonometry functions to convert –sample X value: –sample Y value: =H14*SIN(G14*PI()/180)+$I$12 =H17*COS(G17*PI()/180)+$J$12

25. Graphing Survey Results

26. Graphing Procedure Created new spreadsheet page with results sorted by survey point Used three series of X,Y scatter plots –Left and right banks, fenceline Adjusted for scale Added columns for X & Y UTM coordinates

27. Fieldwork Challenges Riparian vegetation Metallic objects affect compass readings Ditto walkie-talkies Laser bounced off vegetation Couldn’t see squat from original benchmark Survey took longer than expected –Points too close together?

28. Graphing Challenges Excel trig functions wanted inputs as radians, not degrees –Initial X,Y plot made no sense at all –When all else fails, RTFM First pass at plotting stream course didn’t match up with aerial photo –Plot was eXaggerated: X > Y

29. Official’s time out for a measurement

30. Extensions Data should be used for continued monitoring of the site Conduct longitudinal profile of flood control system Finish Planimetric mapping –Map braided sections, ponds, depressions Study should be repeated quarterly or biannually to assess changes in system