370 likes | 510 Views
Nehalem River Basin: Technical Assistance for Watershed Data Synthesis, Restoration, and Outreach Priorities. 4/16/2008. Goal. Support Council’s outreach campaign to recruit landowners for participation in habitat restoration projects. Tasks. Data Synthesis.
E N D
Nehalem River Basin:Technical Assistance for Watershed Data Synthesis, Restoration, and Outreach Priorities 4/16/2008
Goal • Support Council’s outreach campaign to recruit landowners for participation in habitat restoration projects
Data Synthesis TIER I: Robust Data and Spatially Extensive • Coho distribution & Intrinsic Potential • ODFW/Boswell Aquatic Habitat Inventory TIER II: Supporting Data (less robust/extensive) • DEQ 303 (d) list for temperature and e-coli • FLIR (water temperature) • PSU Riparian/LWD/shade analyses • DEQ Macroinvertebrate data • ODFW/OWRD flow restoration priorities • Tidal wetland restoration priorities – Greenpoint Consulting
Data Synthesis TIER III: Supplemental Information • OWEB completed aquatic / riparian restoration projects • Turbidity data (UNWC/DEQ) • Summarize hydrograph (flood history; low flows) ADDITIONAL: Information to Support the Map Products • Geology • Aerial photography
Aquatic Habitat Inventories • ODFW ~360 reaches surveyed (1990-2004) • Boswell Consultants ~ 430 reaches surveyed (2002-2007) • Data used to prioritize reaches for: • LWD placement • Riparian enhancement • Passage barrier removal
Aquatic Habitat Inventories • Large wood placement priority • Coho present • Unconstrained valley bottom (VWI >2) • Channel width small enough for wood to stay in place after floods (ACW < 12 meters) • Currently lacks LWD (<2.0 Key pieces/100m)
Aquatic Habitat Inventories • Riparian enhancement priority • Riparian vegetation dominated by hardwoods, shrubs, or grass • Low shade cover (< 70%) • Conifers not well established in riparian zone • Current land use would allow riparian enhancement
Aquatic Habitat Inventories • Artificial Fish Passage Barriers priority • Low gradient streams • Gradient of the reach made accessible • Area of land drained • Fish presence below culvert • Estimated cost of culvert replacement.
ODEQ303(d)list: FecalColiform(All delisted; TMDL approved) Criteria: Fecal coliform median of 14 organisms per 100 ml; no more than 10% > 43 organisms per 100 ml
PSU Riparian/LWD/shade analyses • 1999 Watershed Analysis • Used draft OWEB methods • Supplemental material using final OWEB methods?
DEQ Macroinvertebrate data • Samples collected 1998 – 2004 • DEQ evaluated aquatic community relative to temperature and fine sediment, summarized each year as 1) Impaired or 2) Equivalent to Reference Condition. • Results mapped as: • GREEN: Not Impaired • YELLOW: Intermediate in evaluation. • RED: Impaired. • ROSE: Flagged as outside the predictive model
Low flows ISWR @ gage 14301000, Nehalem River near Foss: • Priority Date: 5/9/1973 • 7/1 – 9/30 rate = 90 cfs ISWR @ gage 14299800, Nehalem R. near Vernonia: • Priority Date: 5/9/1973 • 7/1 – 9/30 rate = 5 cfs
Geology Volcanics / Intrusives: • Higher gradient, highly bisected drainage network • Larger substrate (pebbles and boulders) and fewer pools. Sedimentary: • Lower gradient, more secondary channels • Sandy substrate, pool rich.
Proposed 6th-field subwatershed summaries: • Coho distribution & Intrinsic potential • LWD & Riparian priorities • 303 (d) listed reaches • Barriers • Completed restoration projects • Landownership • Orthophotos as base map
Questions for TAC: • Sixth field watershed maps & summaries • Prioritization approach (based on summaries) • Deliverables: • Sixth-field maps (hardcopies) • Habitat survey summaries • GIS data for all Tier 1-4 data • Web-based tool for downloading digital data