Climate Change Adaptation and Stream Restoration. Jack Williams;

Transcription

1 Climate Change Adaptation and Stream Restoration Jack Williams; 1

2 Goals for this presentation Develop strategies for adapting streams to climate impacts by Thinking like a watershed Understanding climate change impacts to watershed function Building resistance and resilience to habitats and trout populations Preparing streams for flooding 2

3 What makes stream systems so special? Networked but easily fragmented Linear habitats Multi- dimensional connectivity Subjected to disturbances from aquatic and terrestrial environments 3

4 Watershed Function Receive store release water 4

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7 Important habitats for improving watershed function for stream resiliency Riparian areas Wetlands Mountain meadows Floodplains Stream channels Intermittent streams 7

8 Even small, intermittent streams can be crucial The importance of intermittent streams to developing cold-water patches in receiving warm rivers. Cold-water patches present at 53% (36 of 68) of tributary confluences even when surface stream channels were dry. Ebersole, J.L. et al Predicting the occurrence of cold-water patches at intermittent and ephemeral tributary confluences with warm rivers. Freshwater Science 34:

9 Kaushal et al. 2010: Rising stream and river temperatures in the U.S. Frontiers in Ecology and the Environment 8: s to 2007 Hudson River Delaware River Brandywine Creek Gunpowder River Potomac River Patuxent River Combination of increased urbanization and climate change 9

10 Increasing large storms: largest storm at each station increased average of 10% from

11 Change in heavy precipitation:

12 Response to Tropical Storm Irene and Repeated New England Flooding: 2011 Disturbances and human responses to disturbance extend across jurisdictions and far downstream

13 What does this mean for the Northeast? Warmer temperatures More heavy precipitation events Rising sea level average average Source: National Climate Assessment,

14 What to do? Increase resilience in trout populations and habitats Increase small populations Increase cold-water refuge habitats Improve habitat conditions Reconnect stream network Remove existing stressors Increase redundancy number and distribution of populations Resilience: the capacity of a system to respond to disturbance by resisting damage and recover quickly

15 Increasing stream resilience to disturbance Drought Floods Wildfire Disturbance Strategy Restoration Action Keep water in headwaters longer; connect and recharge aquifers; and increase refuge habitat Increase natural capacity of streamside habitats to absorb and dissipate increased flows Create large wet zones along stream that are resistant to burning; increase width of riparian and wet meadow areas 1. Restore headwater meadows and wetlands 2. Increase meanders 3. Increase the number and size of deep pools 1. Reconnect and restore floodplains 2. Improve culverts for higher flows 1. Increase width and lushness of riparian areas 2. Slow flows, remeander to increase shallow groundwater in meadows 3. Introduce beavers 15

16 Middle Farrer Brook culvert removal November 6 7, 2007 Before (looking upstream) 5 diameter CMP; 2.8 drop After (looking upstream) Road retired; valley fill removed Before (looking downstream) After (looking downstream) 16

17 Long Mountain Brook culvert replacement September 22 29,

18 Long Mountain Brook culvert replacement Before September 22, 2008 (looking upstream) 6 diameter pipe; 1.2 drop After September 29, 2008 (looking upstream) 22 x 8 embedded aluminum box 18

19 Lower Pike Brook culvert removal November 5, 2008 Before (looking downstream) 7 diameter pipe; 1.0 drop (at inlet) After (looking downstream) Road retired; valley fill removed Before (looking upstream) After (looking upstream) 19

20 Johnson Brook culvert remediation June 22 24,

21 Johnson Brook culvert remediation June 22 24, 2009 Before (looking downstream) 4 diameter pipe; 1.3 drop After (looking downstream) 26 clear span; pre-fabricated steel bridge Before (looking upstream) After (looking upstream) 21

22 Slide Brook culvert remediation May 12 26,

23 Slide Brook culvert remediation May 12 26, 2010 Before July 20, 2006 (looking upstream) 6 diameter pipe; 3.4 drop After May 26, 2010 (looking upstream) 42 clear span; pre-manufactured steel bridge 23

24 Upper Farrer Brook culvert remediation August 23 24,

25 Upper Farrer Brook culvert remediation Before August 23, 2010 (looking upstream) Two 2 diameter CMPs; 0.9 drop After August 24, 2010 (looking upstream) 26 clear span bridge installed upstream; fill removed 25

26 Project Design: Crow Creek, Idaho Yellowstone cutthroat Channel straightened for hay cultivation Loss of habitat, especially pools Increased summer temps More frequent flooding and erosion 26

27 Photo of Crow Creek just after diversion of water into new channel 27

28 Crow Creek Restoration Results Stream Gradient (%) Sinuosity Stream Length (ft.) Number of Pools Before ,304 9 After ,

29 Maggie Creek historically a large interconnected LCT system Decades of intense hot season grazing Fragmentation from culvert barriers

30 1993 BLM, Newmont Mining Corps and several and private ranches initiated the Maggie Creek Watershed Restoration Project (MCWRP) Goal: enhance 82 miles of stream and 2000 acres riparian habitat and acres of upland areas Fencing Prescription grazing Seeding/planting

31 Mainstem Maggie Creek

32 Remote sensing to document project effectiveness Open Range Consulting 32

33 BLM/TU on-the-ground monitoring Increased sinuosity Increased riparian vegetation Development of quality pools Improved channel substrates Narrowing and deepening of the stream channel Mainstem

34 Sediment capture has improved greatly Newmont Mines, Inc

35 One other very important partner

36 Lahontan cutthroat trout habitat in southeastern Oregon following Holloway wildfire: 245,505 acres burned Left: stream segment without beavers; right: with beavers 36

37 All culverts replaced in fall 2005 x Beaver was completely isolated = focal stream

38 Beaver creek before culvert removal

39 Beaver creek after culvert removal

40 Presence of larger, migratory Lahontans

41 We can improve water supplies through stream and wetland restoration Improving water quality by slowing flows, improving riparian function and decreasing erosion Improving timing of water delivery and lateseason stream flow by holding water in headwaters and mountain tops for longer periods Increasing resistance to floods and drought by reconnecting streams to floodplains and restoring wetlands 41

42 My thanks to the following BLM, Elko District U.S. Forest Service National Fish and Wildlife Foundation Open Range Consulting My co-authors Helen Neville, Amy Haak, Warren Colyer, Seth Wenger, Stan Bradshaw 42