Aquatic Habitat Guidelines - Stream Restoration Guidelines Spawning Gravel Placement, nourishment, stabilization, and cleaning of spawning gravel Kozmo Ken Bates – Kozmo@AquaKoz.com Title of Section Goes Here

What makes spawning habitat? Aquatic Habitat Guidelines - Stream Restoration Guidelines What makes spawning habitat? Size distribution of substrate Permeability, compaction Hydraulics Depth, velocity, intergravel flow, upwell Water quality; dissolved oxygen Proximity to cover Self-sustaining Upwell figure Title of Section Goes Here

Impacts to Spawning Habitat Loss of substrate Hydraulics of channel incision, straightening, armoring Scour from floods or splash dams Removal or blockage of wood Recruitment blocked Blockage at dams Loss of source by bank armoring Intrusion of fines Single event or chronic Instability during spawning

Spawning Gravel – Other Impacts Loss of upwell flow when gravel bars lacking Loss of invertebrate productivity in compacted bed ll

Spawning Gravel Restoration Methods Direct placement - spawning pads Nourishment Trapping Stabilization Side channels (other technique) Cleaning

Geomorphic Context

Spawning Gravel Placement Aquatic Habitat Guidelines - Stream Restoration Guidelines Spawning Gravel Placement Direct placement - Pads Appropriate where gravel sources are lost Temporary fix unless hydraulics are appropriate. Tailout of drop structure or constriction with specific headloss Spring channel enhancement “Lost” implies there was gravel there naturally Title of Section Goes Here

Spawning Gravel Pads

Spawning Pads - Risks Displaces and affects other habitats “Attractive nuisance” Gravel is not hydraulically sorted or place and therefore unstable for spawning Gravel is not persistent in high energy areas Gravel may not be persistent over hard bed Potential low depth passage barrier

Spawning Gravel Nourishment Create gravel bluff or bar High flows distribute material “naturally” Applies downstream of gravel traps (dams) Restocking of bar or bluff is based on monitoring of bar (for quantity) or gravel downstream (for habitat) Can be appropriate above high energy channels to create pocket gravel

Washington Spawning Nourishment Sites Mitigation below dams Cedar River Green River Cowlitz River Spokane River

Cedar River Gravel Nourishment Downstream of Landsburg Dam About 1,000 cy to placed 2001-2006 except 2002 Material specified; generally 5 to 50 mm Placed as “gravel bar” to be washed downstream

Cedar River gravel nourishment plan 2 Downstream cross-sections Placement berm 1 Control cross-section 2002 Channel work City of Renton, Golder Associates drawing

City of Renton, Golder Associates photo

Cedar River Gravel Monitoring Care of fish Timing Snorkel surveys Erosion and sediment control Turbidity monitoring Gravel supplementation Sieve analysis of placed material Channel cross-sections at site and control Pebble counts at transects downstream and control

Results Cross-Section 3; 2001-2006 (my trend lines by eye) “Spawning gravel” 10 - 60 mm City of Renton, Golder Associates data

Results Cross-Section 4 2001-2006 (my trend lines) “Spawning gravel” 10 - 60 mm City of Renton, Golder Associates data

Aquatic Habitat Guidelines - Stream Restoration Guidelines Keswick Dam, Sacramento R Feeder bluff supplementation 100,000 cy gravel added at 8 sites Resulting Chinook redd Keswick Dam - During 1990 and 1991, the California Department of Water Resources placed 100,000 cubic yards of spawning gravel at eight locations in the 12 mile reach between Keswick Dam and Clear Creek. Anadromous fisheries in the Sacramento River Basin have suffered significant declines in the years since Shasta and Keswick Dam were completed in the 1940s. The reduction in fish populations are attributed to many causes including loss of spawning gravel habitat below Keswick Dam. One million cubic yards of spawning gravel are estimated to be needed to replace the loss, and the 1990's placements represented only the first phase of a larger spawning habitat restoration project. Feeder bluff Title of Section Goes Here

Green River Gravel Nourishment Corps 1125 project Now part of Howard Hanson Dam Bi-op for Chinook and bull trout Objectives Increase spawning for coho, Chinook, steelhead Reconnect side channels and floodplain Reverse bed armoring Restore natural gravel transport

Aquatic Habitat Guidelines - Stream Restoration Guidelines Other Project Parts Gravel Nourishment Loose wood Log jams Loose wood: 50% of large debris that accumulates in reservoir plus 50 to 70 tons of small debris 2 log jams associated with gravel placement. See aerial. Title of Section Goes Here

Debris jams Nourishment bars Nourishment bars USACE photo

Monitoring Intensive monitoring for five years Background for management of 50-year project

Gravel Monitoring Questions Are gravel berms effectively providing spawning gravels each year? What is the rate of gravel transport through the reach? How does gravel size affect transport? How is substrate composition changing downstream? What is the effect of gravel nourishment on Chinook and steelhead spawning? Log jam and loose wood monitoring also

Geomorphology Monitoring Changes in channel morphology? Change in water surface elevation? Channel migration? Localized storage of spawning gravel? Signs of bank erosion? Due to any or all three activities.

Spawning Monitoring Activities Aquatic Habitat Guidelines - Stream Restoration Guidelines Spawning Monitoring Activities Low flow / spring survey of gravel berms Post high flow / visual inspection of gravel berms Photo points Survey cross-sections Pebble counts Gravel patch mapping / aerial photo analysis Side channel water levels (G) Fall spawner survey Habitat mapping (H) Hydrology Patch composition is estimated by eye – that’s somewhat of a problem especially as project and gravel age – now looking more at total gravel volume moving through sites – field crew has calibrated their eyes at sites upstream of gravel placement Title of Section Goes Here

See recommendations for future monitoring

USACE photo

Photopoint 17 Looking downstream at ELJ2 Sept 2003 July, 2005

Aquatic Habitat Guidelines - Stream Restoration Guidelines Before after shots Models greatly underestimated entrainment of gravel – 50% of gravel scoured in two events lower than median flow – 90% scoured before design flow of 1.5-year event More gravel will be needed more frequently Will build bars higher – approaching idea of bluffs Title of Section Goes Here

Aquatic Habitat Guidelines - Stream Restoration Guidelines Also seeing side channel inundated more frequently USACE photo Title of Section Goes Here

USACE contact

Aquatic Habitat Guidelines - Stream Restoration Guidelines Risks Fish spawning on fresh gravel – Green River Material transported at low events Constriction of channel changes hydraulics locally 1 Green River - high flows in Sept and Oct – flow sheets across bars - pinks spawning material and then bar eroded – Solution: build higher mounds to keep flow off top of bar during spawning – compare that to bluffs Considering placement during winter – trade-off of spawning on fresh gravel vs placement during incubation 2 Green River gravel moving through pretty fast – more gravel will be needed more frequently – have placed 4,000 cy per year - total authorization is 3 times that. This year will put in 8,000 cy. Changed gravel spec from 4 to 5 and now going from 4 to 6. 50% Some material was transported 2 miles in 2 years Title of Section Goes Here

Spawning Gravel Trapping Outlet cr

Cedar Cr Fish First project

Cedar Cr Fish First project

Risks Installation of trapping structures Backwater effects

Spawning Gravel Cleaning Cleaning of in-place channel bed Mechanical Hydraulic Temporary solution Use only if one-time sediment effect or source is remedied High cost Not a current practice

Spring channels

Spawning Gravel Cleaning “Gravel Gertie” Jets clean to 12” deep Fines decreased 3 to 78% Siltation partially confined in hoods

Spawning Gravel Cleaning Other Cleaning Mechanisms Maybe drop this slide

Spawning Gravel Cleaning Effects High level of disturbance Flattens and lowers streambed Temporary “attractive nuisance” of unstable bed Impact is limited with smaller equipment Removes invertebrates Re-colonized within weeks Water quality impacts moves some of the sediment downstream

Spawning Gravel Complementary Techniques Restore channel profile, floodplain connectivity Remedy sources of fines Add roughness to trap gravel Debris, boulders, drop structures Add structure to distribute and sort gravel

Spawning Gravel Restoration Uncertainties Aquatic Habitat Guidelines - Stream Restoration Guidelines Spawning Gravel Restoration Uncertainties Uncertainties are high for placement Depends on flow events Uncertainty low for supplementation Monitoring required K Bates Title of Section Goes Here

Spawning Gravel Monitoring

Aquatic Habitat Guidelines - Stream Restoration Guidelines Last thoughts To be sustainable, spawning gravel is the right combination of Gravel source Hydrology Hydraulics It’s tough to improve on natural spawning habitats. Without all 3, it’s not spawning habitat. Title of Section Goes Here