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North Coast Anadromous Creeks Snorkel Fish Counts and Habitat Survey 2019 Data Summary

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North Coast Anadromous Creeks Snorkel Fish Counts and Habitat Survey 2019 Data Summary North Coast Anadromous Creeks Snorkel Fish Counts and Habitat Survey 2019 Data Summary Prepared by: City of Santa Cruz Water Department June 2020 Please cite as follows: Berry, C., Bean, E., Bassett, R., Retford, N., Sedoryk, M., and Hagar, J. 2020. North Coast Anadromous Creeks Snorkel Fish Counts and Habitat Survey 2019 Data Summary. Prepared for the City of Santa Cruz Water Department. Santa Cruz, CA. This Page Intentionally Left Blank Table of Contents INTRODUCTION ................................................................................................................................................ 7 SITE DESCRIPTIONS ........................................................................................................................................ 7 LAGUNA CREEK .................................................................................................................................................... 7 LIDDELL CREEK .................................................................................................................................................... 8 MAJORS CREEK ..................................................................................................................................................... 9 METHODS .......................................................................................................................................................... 10 DATA COLLECTION ............................................................................................................................................. 10 DATA ENTRY ....................................................................................................................................................... 11 DATA ANALYSIS .................................................................................................................................................. 11 RESULTS ............................................................................................................................................................ 12 DISCUSSION ...................................................................................................................................................... 14 LAGUNA CREEK .................................................................................................................................................. 14 LIDDELL CREEK .................................................................................................................................................. 15 MAJORS CREEK ................................................................................................................................................... 16 CONCLUSION ................................................................................................................................................... 17 REFERENCES ................................................................................................................................................... 18 3 List of Figures Figure 1: Map of the North Coast Creeks Surveyed. The anadromous reaches of Majors Creek, Laguna Creek, and Liddell Creek are surveyed annually by means of visual snorkel surveys downstream of the Water Department’s diversions. .............................................................................. 20 Figure 2: Anadromous Laguna Creek Hydrograph, Water Year 2018 ................................................. 21 Figure 3: Anadromous Liddell Creek Hydrograph, Water Year 2018 .................................................. 22 Figure 4. Anadromous Majors Creek Hydrograph, Water Year 2018 ................................................... 23 Figure 5: Oncorhynchus mykiss (steelhead) and Oncorhynchus kisutch (coho salmon) density by size class in Anadromous Laguna Creek from 2006-2019. .......................................................................... 24 Figure 6: Oncorhynchus mykiss (steelhead) and Oncorhynchus kisutch (coho salmon) density by size class in Anadromous Liddell Creek from 2006-2019.. .......................................................................... 25 Figure 7: Oncorhynchus mykiss (steelhead) density by size class in Anadromous Majors Creek from 2006-2019.. ............................................................................................................................................ 26 Figure 8: Oncorhynchus mykiss (steelhead) densities by size class in North Coast streams (Anadromous Majors, Liddell, and Laguna) in 2019.. .......................................................................... 27 Figure 9: Salmonid density by size class in North Coast streams (Majors, Laguna, and Liddell combined) 2006-2019. ........................................................................................................................... 28 Figure 10: Salmonid density per 100 feet by pool habitat type observed in Anadromous Laguna Creek, 2019.. .......................................................................................................................................... 29 Figure 11: Salmonid density per 100 feet by pool habitat type observed in Anadromous Liddell Creek, 2019........................................................................................................................................................ 30 Figure 12: Salmonid density per 100 feet by pool habitat type observed in Anadromous Liddell Creek, 2018........................................................................................................................................................ 31 4 List of Tables Table 1: Tabulated summary of the historical average (2006 – 2019) and 2019 snorkel surveys conducted in Laguna, Liddell, and Majors Creeks.. .............................................................................. 33 Table 2: Detailed results from 2019 Laguna Creek snorkel survey. ...................................................... 34 Table 3: Detailed results from 2019 Liddell Creek snorkel surveys. .................................................... 35 Table 4: Detailed results from 2019 Majors Creek snorkel survey. ...................................................... 36 Appendices APPENDIX A - SANTA CRUZ CITY NORTH COAST FISH SNORKEL SURVEYS FALL 2018 ............... 37 APPENDIX B - SITE MAP ................................................................................................................................. 40 APPENDIX C - SAMPLE REACH INSTRUCTIONS ....................................................................................... 42 APPENDIX D - FIELD DATA SHEET .............................................................................................................. 43 5 This Page Intentionally Left Blank Introduction The objective of this summary report is to present the methods and results for the north coast anadromous creeks fish surveys conducted in 2019 by the City of Santa Cruz Watershed staff. Data collected from 2006-2018 are included where appropriate, allowing comparison over the course of over ten years. Surveys were conducted by snorkeling pools and counting the number and size of steelhead trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch) observed. Quantitative and qualitative habitat data were also collected. Site Descriptions The following site descriptions are adapted from Balance Hydrologics (Chartrand, 2006). Laguna Creek Laguna Creek, located on the western slopes of the Santa Cruz Mountains, drains a watershed of about 7.79 square miles before flowing into the Pacific Ocean. The watershed ranges in elevation from sea level to 2,440 feet above mean sea level. Mean annual precipitation is largely dependent upon elevation and ranges between 30 and 44 inches in the Laguna Creek watershed (Rantz, 1971)1. About 85 percent of the total annual rainfall typically occurs during the wet season (November through March). Foggy days are common throughout the year and can contribute a measurable component to the total precipitation from fog drip. Vegetation varies with elevation, aspect and soil type, but is primarily redwood and mixed deciduous forest, with substantial areas of grassland, xeric sandy soil chaparral, and cultivated lands. Land use within the Laguna Creek watershed is primarily rural residential and rangeland with portions of public lands managed by California State Parks, the California Department of Fish & Wildlife (Bonny Doon Ecological Preserve), the Bureau of Land Management, and the City of Santa Cruz. Timber harvests sometimes occur in the watershed and there are small areas of agricultural use. Approximately 600 acres burned in June 2008 between Pine Flat and Empire Grade roads. Minimum bypass flows for various life stages of anadromous salmonids were maintained at the City’s diversion on Laguna Creek during water years 2016 - 2019. However, downstream private 7 diverters significantly and routinely reduced these bypass flows, particularly in the dry summer and fall months. The Anadromous Laguna site was sampled as two separate reaches: Reach 1 (SCWD-1) extends from Hwy 1 upstream approximately 1,500 feet and reach 2 (SCWD-2) from the downstream limits of the Coast Dairies property upstream approximately 1,500 feet to a boulder pool. Liddell Creek Liddell Creek, extending from the community of Bonny Doon to the Pacific Ocean, drains a relatively small watershed area of 3.17 square miles; however sub-surface karst connections may increase the Liddell
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