Ashland Watershed Assessment & Action Plan
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AAsshhllaanndd WWaatteerrsshheedd AAsssseessssmmeenntt && AAccttiioonn PPllaann December, 2007 Bear Creek Watershed Council PO Box 1548, Medford, Oregon 97501 Funded by the Oregon Watershed Enhancement Board OWEB Grant #204-281 Bear Creek Watershed Council PO Box 1548, Medford, Oregon 97501 (541) 840-1810 www.bearcreek-watershed.org PROJECT SUMMARY Ashland is a venerable village with a postcard-like setting; an urban center stretched along a narrow terrace at the base of very steep ridges and erodible canyons that periodically funnel warm rain and snow melt down from the mile of mountain rising above town. Stormwater from a dozen flood-prone creeks challenges the resources of the City and homeowners as it rushes across the Ashland Terrace. However, the Ashland Watershed Assessment demonstrates that these creeks can be a valued community asset, providing a great opportunity for individual landowners, homeowner associations, and the City to cooperatively improve watershed health and function. We found that many of the small streams have perennial summer flows due to augmentation from summer irrigation. This condition promotes streamside vegetation that can stabilize stream banks, filter runoff, reduce erosion, and provide riparian corridors, green ribbons of habitat for birds and other urban wildlife connecting Bear Creek’s flood plain to the forested slopes above. The associated vegetation canopy helps keep water cool to carry more oxygen for fish and aquatic life. The City recognizes that these streams add value to the watershed and encourages increased landowner participation in riparian corridor and wetland protection. We found the City has engaged consultants to recommend improved stormwater management practices, to quantify infrastructure needed to address runoff and erosion issues, and to assess the impact from high development areas on existing facilities. A pro-active policy for constructing wetlands that filter stormwater and detain storm surges continues to show favorable results. We noted coho salmon have been found in several creeks, and steelhead and steelhead fry are present in Lithia Park near City Hall - clear evidence that Ashland’s efforts to protect salmonids and remove fish passage barriers has brought results. Stream surveys identified several fish barriers at irrigation diversions and a need for late season flow restoration in Neil Creek. Action Plan priorities identified in this assessment include 14 habitat and restoration projects, 5 stormwater management projects, 8 fish passage barrier projects, and a series of informational and educational activities. Outreach during the assessment process has shown that there is community interest in practices that control sediment, pollution, and soil erosion; tours and workshops to see what has worked and how to get results, and monitoring to verify progress. These projects and activities help build community commitment and sustained public support while assuring a well-functioning and productive watershed. i TABLE OF CONTENTS CHAPTER I – Introduction and Watershed Issues OWEB Process and Project Team ........................................................................ I -1 Watershed Ownership and Neighborhoods ........................................................... I - 3 Community Involvement and Issues ...................................................................... I - 3 REFERENCES ...................................................................................................... I -10 CHAPTER II – Historic Conditions Pre-settlement Vegetation (Pre-1850) ................................................................... II - 3 Native Americans .................................................................................................. II - 5 Early Settlement Vegetation 1850 to 1900 ............................................................ II - 6 Vegetation Change after 1900 ............................................................................... II - 6 Fish Population ..................................................................................................... II - 7 Comparing “Before and After” Photos ................................................................... II - 8 Timeline of Human Activities Affecting Streams .................................................... II - 19 REFERENCES ...................................................................................................... II - 21 CHAPTER III – Stream Channel Classification Introduction ........................................................................................................... III - 1 Climate .................................................................................................................. III - 2 Geology ................................................................................................................. III - 2 Stream Channel Classification .............................................................................. III - 3 Urban Stream Classification .................................................................................. III - 6 General Application to the Ashland Assessment Project ....................................... III - 6 REFERENCES ...................................................................................................... III - 8 CHAPTER IV – Hydrology & Water Use Sources of Water .................................................................................................. IV - 1 Water Losses ........................................................................................................ IV - 9 Water Use ............................................................................................................. IV - 10 Critical Questions .................................................................................................. IV - 13 REFERENCES ...................................................................................................... IV - 14 CHAPTER V – Riparian and Wetlands Assessment Bird Populations in Riparian Areas ........................................................................ V - 7 Other Wildlife......................................................................................................... V - 11 Wetlands ............................................................................................................... V - 11 REFERENCES ...................................................................................................... V - 13 CHAPTER VI – Sediment Source Assessment Geology ................................................................................................................. VI - 1 Sediment Production Processes............................................................................ VI - 1 Sediment Sources ................................................................................................. VI - 2 Oregon DEQ Total Maximum Daily Load................................................................. VI - 6 Sediment Production Rates and Monitoring .......................................................... VI - 9 ii Supplemental Information: Critical Questions ........................................................ VI - 11 REFERENCES ...................................................................................................... VI - 12 CHAPTER VII – Channel Modification Assessment Impervious Surfaces.............................................................................................. VII - 1 Dams .................................................................................................................... VII - 1 Roads ................................................................................................................... VII - 2 Storm Drains ......................................................................................................... VII - 2 Culverts ................................................................................................................. VII - 2 Irrigation Canals .................................................................................................... VII - 2 Issues Related to Channel Modification................................................................. VII - 3 Critical Questions .................................................................................................. VII - 5 REFERENCES ...................................................................................................... VII - 8 CHAPTER VIII - Water Quality Assessment 2007 Bear Creek Watershed TMDL ...................................................................... VIII - 1 Potential Point Sources of Thermal Pollution ......................................................... VIII - 2 1992 Bear Creek TMDLs ....................................................................................... VIII - 9 Quality of Ashland’s Drinking Water ...................................................................... VIII - 11 REFERENCES ...................................................................................................... VIII -14 CHAPTER IX – Fish and Aquatic Wildlife Introduction ........................................................................................................... IX - 1 Note on Anadromy ................................................................................................ IX - 1 Aquatic Species Found in the Ashland Watershed Assessment Area....................