The Nash Stream Project: Restoring River Processes and Connectivity
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The Nash Stream Project: Restoring river processes and connectivity Jim MacCartney, Principal, River Solutions LLC John Magee, Fish Habitat Biologist, NH Fish and Game Department 1 • Watershed area: 115 km2 (44 mi2) • Stream length: 21+ km (13+ mi) • 3rd and 4th order • Nine major perennial tributaries • Ownership: > 90% public • Landscape/vegetation: glaciated with mixed forest • Minimal infrastructure • Native salmonid: EBT 2 History • Working forest • 1852 to present 3 Dam break – May 1969 Flow 4 Flood of record USGS 01130000 Upper Ammonoosuc River near Groveton, NH 800 700 /s 3 600 500 400 300 200 Annual Peak Streamflow in m 100 0 1941 1951 1961 1971 1981 1991 2001 2011 Year 5 1969 flood footprint 6 Impacts of flood • Loss of LWM and channel complexity • Disconnected floodplains • Depleted riparian forest • Habitat fragmentation - impassable culverts 7 Water quality impairments Section 319 nonpoint source Non-pollutant Solutions • Habitat degradation • Remediate undersized culverts • Hydrologic modification • Restore natural river processes • Channel morphology • Instream habitat • Floodplain connection 8 Watershed plan • EPA-approved alternative ‘a-i’ (geomorphic based) • Determined causes of channel instability • Delineated and characterized 95 segments • Identified restoration options • Condition of eight geomorphic and habitat features, including pools, wood, and riparian vegetation 9 2005 comprehensive fish survey 2005 stream crossing assessment (AOP) 2007 geomorphic assessment Instream restoration designs Placed Placed Mid- Mobile Chop and Boulder wood on- wood in- channel wood Treatment of choice Needs Segment Needs (threshold) Appropriate treatments Scores drop clusters bar Rock weirs channel log jams additions Access (suggested by model) total Chop and drop, Placed wood on-bar, Placed 17 Wood wood in-channel, Mobile wood additions All Needs 52.6 40.2 54.6 5 Pick from list 17 Recommended 4.6 3.0 4.8 4.6 Bang-for-buck 11.6 4.1 3.9 6.2 Chop and drop, Boulder clusters, Rock weirs, Pools, Wood, Placed wood in-channel, Bank cutting/Flow 16I Meanders diversion, Mobile wood additions All Needs 79.2 55.4 72.0 81.9 72.0 3 Pick from list 28 Recommended 9.8 5.8 6.8 10.0 8.8 Bang-for-buck 11.6 5.9 4.0 3.9 6.2 Boulder clusters, Rock weirs, Placed wood in- Pools, Wood, channel, Bank cutting/Flow diversion, Mobile 16H Meanders wood additions All Needs 64.2 85.2 95.2 84.0 5 Pick from list 35 Recommended 5.8 6.8 10.0 8.8 Bang-for-buck 5.9 4.0 3.9 6.2 Boulder clusters, Placed wood on-bar, Bar apex boulders, Bar apex log jams, Placed wood in-channel, Mid-channel log jams, Trim Pools, Wood, boulder bar/bkf bench, Bank cutting/Flow Meanders, diversion, Floodplain lowering, Mobile wood 16G Adjustment additions All Needs 63.2 76.8 93.8 122.8 82.8 5 Pick from list 34 Recommended 7.2 9.6 11.8 16.0 10.4 Bang-for-buck 5.9 4.1 3.9 3.5 6.2 Riparian plantings, Breach or remove berm, Boulder clusters, Rock weirs, Placed wood in- channel, Bank bioengineering, Trim boulder Flows, Pools, Wood, bar/bkf bench, Bank cutting/Flow diversion, 16F Adjustment, Canopy Floodplain lowering, Mobile wood additions All Needs 67.4 90.6 99.9 88.4 5 Pick from list 37 Recommended 9.0 12.2 14.7 13.2 Bang-for-buck 5.9 4.0 3.9 6.2 13 Restoring natural channel processes • Mimic nature (random, not neat or orderly) • Match width, depth, slope and substrate • Use native materials similar to those nearby (color, type, composition, species) • Avoid/minimize anchors, cables, and synthetic fabrics • Keep all of the pieces; do no harm 14 Slide Brook culvert remediation May 12—26, 2010 Pre-replacement – looking upstream Post-replacement – looking upstream July 20, 2006 May 26, 2010 Horseshoe Brook culvert replacement May 6—10, 2013 16 Restoration using large woody material: Why use large wood? • Restore channel complexity • Form • Pool frequency, size, quality • Encourage meanders • Build bars • Function • Less rigid material than rock (adjustable) • Diversity of fish habitat, cover • Organics for macroinvertebrates • Dissipate energy • Process • Range of flow regimes: slow/deep, fast/shallow, etc. • Sorting of bed materials • Sediment storage 17 Wood-boulder clusters (at different flows) 18 Tributary wood additions Engineered log jams 20 Engineered log jams Mobile wood additions • Machine-harvested and placed • Excavator with thumb • Easy access points • Sound, whole trees—rootwad upstream • Various elevations in and across channel 22 Wood deployment 23 Transport at high flow mwv 24 25 Major accomplishments Retired four stream crossings (middle Farrer; lower Pike; two unnamed tributaries) Replaced nine culverts (Columbia Rd. (3); upper Farrer; Horseshoe; Johnson; Long Mountain; upper Pike; Slide) Restored 7.8 miles mainstem (Nash Stream Road Bridge to West Side Road) Replenished 4.8 miles large wood (East Branch; Emerson; Johnson; Long Mountain; Pike) 26 Section 319 funded restoration work • Culvert replacement • Upper Farrer; middle Columbia Rd.; Horseshoe; upper Pike; Slide • Road relocation (0.3 miles) • Instream restoration (7.8 miles) • Mobile wood additions; log jams, channel diversion weir; wood-boulder clusters; large wood placements • Large wood replenishment • Emerson Brook and Johnson Brook • Post-construction monitoring 27 Funding sources Year Source Amount 2004; 2005 NH Charitable Foundation (2) $38,000 2005 Trout and Salmon Foundation $10,000 2005 Ammonoosuc Chapter TU $2,500 2006-2017 Upper Connecticut M&E Fund (5) $674,300 2006 TU Embrace-A-Stream $10,000 2006 Fish America Foundation $12,000 2006 NRCS Wildlife Habitat funds (WHIP) $145,805 2006 NH Division of Forest and Lands $22,000 2006-2015 NH Fish and Game Department (3) $195,000 2007; 2010 NHDES - §319 Nonpoint Program (2) $319,856 2011 Second Congregational Society $254 2011 Wirebelt, Inc. $800 2012; 2015 Eastern Brook Trout Joint Venture (2) $100,000 2015; 2016 NHDES - Aquatic Resource Mitigation Fund (2) $20,000 2017 Basil Woods Chapter TU $2,500 TOTAL $1,553,015 Project partners • NH Council Trout Unlimited • NH Fish & Game Department • NH Division of Forest and Lands Contributors and technical assistance • Ammonoosuc & Basil Woods Chapters TU • Second Congregational Society • Field Geology Services • Trout and Salmon Foundation • Fish America Foundation • Upper Connecticut River MEF • Natural Resource Conservation Service • USDA Forest Service • New Hampshire Charitable Foundation • US Fish and Wildlife Service • NH Department of Environmental Services • Wirebelt, Inc. 29 Photo by Dianne Timmins, NHFGD [email protected] | [email protected] 30.