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Aquatic Restoration Rivers Unit 6, Module 25 July 2003.

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Presentation on theme: "Aquatic Restoration Rivers Unit 6, Module 25 July 2003."— Presentation transcript:

1 Aquatic Restoration Rivers Unit 6, Module 25 July 2003

2 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s2 Objectives Students will be able to:  describe current statistics regarding the physical degradation, water quantity, and water quality of streams.  identify goals and considerations of stream restoration.  evaluate the factors that influence the dynamic equilibrium of streams.  provide examples of potential causes of bank erosion.  describe restoration techniques used to alter accelerated bank erosion.  identify potential causes and restoration measures for altered width/depth ratios in streams.  identify potential causes and restoration measures for altered sinuosity in streams.  identify potential causes and restoration measures for altered flow in streams.  identify potential causes and restoration measures for altered temperatures and dissolved oxygen levels in streams.

3 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s3 Overview  Introduction  Lake Restoration  Stream Restoration  Wetland Restoration

4 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s4 Restoration philosophy “ Process of returning a river or watershed to a condition that relaxes human constraints on the development of natural patterns of diversity.

5 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s5 Restoration philosophy Restoration does not create a single, stable state, but enables the system to express a range of conditions dictated by the biological and physical characteristics of the watershed and its natural disturbance regime” (Frissell and Ralph 1998)

6 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s6 State of the Streams Approximately 3.2 million miles (5.15 km) of streams in the U.S.  Only about 2% of streams remain in relatively undisturbed, natural conditions  Less than 1/3 of 1% preserved as national and scenic rivers (Echeverria 1989)

7 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s7 Physical Degradation 40% U.S. perennial streams affected by siltation Miles Percent Siltation265,00039.8 Bank erosion152,00022.8 Channel modifications143,50021.5 Migratory blockages 9,700 6.0 Bank encroachment 9,000 1.4 (Modified from Judy et al. 1984)

8 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s8 Water Quantity Issues 40% U.S. perennial streams affected by low flows MilesPercent Diversions Agricultural105,00015.8 Municipal 10,700 1.6 Industrial 3,290 0.5 Dams Water supply 30,800 4.6 Flood control 26,900 4.0 Power 24,800 3.7 (Modified from Judy et al. 1984)

9 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s9 Water quantity issues  Over 2.5 million dams in the U.S. (Johnston Associates 1989)  Only about 75,000 dams more than 6 feet tall (USACE 2002)  600,000 stream miles are under reservoirs (Echeverria 1989)

10 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s10 Water Quality Issues Over 41% of nation’s streams impacted by turbidity Miles Percent Turbidity277,00041.6 Elevated temperature215,00032.3 Excess nutrients144,00021.6 Toxic substances 90,90013.6 Dissolved oxygen 75,40011.3 pH 26,000 3.9 Salinity 14,600 2.2 Gas supersaturation 5,500 0.8 (Modified from Judy et al. 1984)

11 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s11 Stream restoration goal To alter biophysical processes and structures to promote a dynamic equilibrium with diverse abundant aquatic species and channel stability

12 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s12 Other stream restoration considerations In addition to in-stream habitat, current restoration projects should consider:  Geomorphology at a watershed scale  Inclusion of physical scientists (interdisciplinary)  Fluvial geomorphology, sediment transport, channel hydraulics, hydrology  Historical information to document the evolution of the channel  How processes have been altered by human activities in the watershed

13 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s13 Stream channel stability  “Morphologically defined as the ability of the stream to maintain, over time, its dimension, pattern, and profile in such a manner that it is neither aggrading nor degrading and is able to transport without adverse consequences the flows and detritus of its watershed” (Rosgen 1996)

14 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s14 Dimension: (cross section)  Width/depth ratio at bankfull stage  Entrenchment ratio  Width of flood prone area/bankfull width  Dominant channel materials  sizes or types Image: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by FISRWG.

15 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s15 Pattern (plan view)  Sinuosity  stream length/valley length  Meander width ratio (secondary measurement)  meander belt width/bankfull width Image: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by FISRWG.

16 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s16 Profile (longitudinal)  Slope  difference in elevation/stream length  Bed features (secondary measurement)  Description of characteristics such as riffle/pools Image: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by FISRWG.

17 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s17 Dynamic equilibrium Q s. D 50 in balance with Q w. S Q s = sediment load Q w = stream discharge D 50 = sediment size S = stream slope (Lane 1955) Image: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by FISRWG.

18 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s18 Dynamic equilibrium Qualitatively…variables are in balance at channel equilibrium. If one factor changes, the other variables change to reach a new equilibrium. Sediment load Sediment size Stream discharge Stream slope Image: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by FISRWG.

19 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s19 How would the stream respond... if stream discharge (Qw) increased?  Width, Depth (Dimension)  Meander wavelength (Pattern)  Slope (Profile) if sediment load (Qs) increased?  Width, Depth (Dimension)  Meander wavelength? (Pattern)  Slope (Profile)

20 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s20 How would the stream respond... if stream discharge (Qw) increased and sediment load (Qs) decreased?  Width, Depth (Dimension)  Sinuosity, Meander wavelength (Pattern)  Slope (Profile)

21 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s21 Potential causes of bank erosion  Vegetative clearing  Channelization  Streambed disturbance  Dams  Levees  Soil exposure or compaction  Overgrazing  Dredging for mineral extraction  Woody debris removal  Piped discharge  Water withdrawal

22 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s22 Measuring bank erosion potential Measure the following variables then rate from very low to extreme  Bank height/bankfull height  Root depth/bank height  % root density  Bank angle (degrees)  % Surface protection  Soil stratification  Particle size Image: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by FISRWG.

23 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s23 Restoration Techniques for Accelerated Bank Erosion  Bank shaping  Fascines  Live Staking  Root wads

24 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s24 Bank shaping Purpose Alter the bank angle so that bank angle (degrees) that it is stable Efficacy Usually necessary before vegetation can be added to the bank Image: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by FISRWG.

25 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s25 Fascines  Live shrubs (willow) bundled together with rope  Purpose: Vegetate eroded banks providing stabilization and habitat (root density and soil surface protection) Image: Ontario's Stream Rehabilitation Manual.

26 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s26 Fascines  Efficacy Simple and works immediately because shrubs grow rapidly to hold soil in place Higher success if allowed to grow for one year before water rerouted Works well by itself for small streams

27 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s27 Live staking Purpose: Vegetate eroded banks providing stabilization and habitat (root density and soil surface protection) Efficacy Effective with small erosion problems or in combination with brush mattresses, fascines, or erosion control blankets Best if allowed to grow for one year before water rerouted Image: Ontario's Stream Rehabilitation Manual.

28 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s28 Live staking Image: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by FISRWG.

29 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s29 Root wads Purpose Deflects current away from unstable banks Provides complex instream cover for fish and substrate for aquatic macroinvertebrates Efficacy Effective with larger erosion problems Image: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by FISRWG.

30 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s30 Stream restoration case study #1 Vermilion River, Minnesota  Impact - bank erosion  Over 220 feet in length, 8 feet above water level in one spot  Receded over 6 feet in 1 year

31 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s31 Vermilion River restoration  Goals of 1997-2000 Restorations  Reduce the sediment load to improve downstream water quality  Create more productive fish habitat  Protect the adjacent property  Provide a demonstration project for other erosion problems on the Vermillion River

32 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s32 Vermilion River: Methods  Fascines  Rootwads

33 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s33 Vermilion River: Methods  Bank shaping  Boulder vanes

34 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s34 Live Staking

35 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s35 Vermilion River restoration  Evaluation  Property is protected  Valuable as demonstration projects  Clear objectives  But, were objectives based on stream morphology or just chosen because the techniques are new?  Unknown if fish habitat and sediment loads have been measured

36 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s36 Altered width/depth ratio Potential causes:  Vegetative clearing  Water withdrawal  Channelization  Streambank armoring  Streambed disturbance  Dams  Levees  Hard surfacing  Roads and railroads  Overgrazing  Reduction of floodplain  Dredging for mineral extraction  Bridges  Woody debris removal  Piped discharge

37 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s37 Altered width/depth ratio: restoration Wing deflectors: Purpose Reduces the width to depth ratio Forms scour pools and increases velocity and depth providing habitat Single wing deflectors can direct current away from eroding banks Image: Ontario's Stream Rehabilitation Manual.

38 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s38 Wing Deflectors Efficacy Effective, but require monitoring and maintenance Image: Ontario's Stream Rehabilitation Manual.

39 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s39 Potential causes of altered sinuosity  Channelization  Streambank armoring  Streambed disturbance  Dams  Levees  Hard surfacing  Reduction of floodplain  Land grading  Woody debris removal  Piped discharge

40 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s40 Sinuosity: restoration Carbon Copy Technique Restore stream to the pattern before disturbance Use historical aerial photographs May not be stable with current conditions Empirical relationships Measure bankfull width and discharge then calculate meander length and sinuosity Use if soil conditions have remained the same

41 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s41 Sinuosity: restoration Systems approach Analyze meanders on a watershed scale Evaluate geomorphology Compare to find dominant meander wavelength (Fourier analysis)

42 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s42 Potential causes of altered flow  Vegetative Clearing  Channelization  Streambank armoring  Water withdrawal  Dams  Levees  Soil exposure or compaction  Irrigation or drainage  Hard surfacing  Overgrazing  Roads and railroads  Reduction of floodplain  Land grading  Piped discharge

43 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s43 Altered Flow: Restoration Dam Removal Sediment Needs treatment if contaminated Concentrations of nutrients in sediment probably high Hard to predict what will happen when dam removed Stream type will evolve after dam removal

44 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s44 Dam removal 1. Breaching of dam 2. Temporary coffer-dams built to work behind 3. Sediment removal 4. Disposal of timbers off-site

45 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s45 Increased Water Temperatures and Reduced Instream Oxygen Concentrations Potential Causes  Vegetative Clearing  Channelization  Streambank armoring  Water withdrawal  Dams  Levees  Hard surfacing  Overgrazing  Reduction of floodplain  Dredging for mineral extraction  Woody debris removal  Piped discharge

46 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s46 Altered Temp and DO: Restoration Revegetation of riparian areas Site preparation: Possibly re-grade bank Control existing exotic species Check the soil conditions (lack of nutrients) Tillage and mulching may increase planting success and decrease weediness Best management practices such as fencing livestock

47 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s47 Revegetation Method: Use a reference site Determine species diversity, horizontal and vertical structure of canopy, sub-canopy, understory, and ground-layer Determine which plants will recolonize site naturally Small existing plant populations, seed bank, nearby populations of wind and animal dispersed species a reference site

48 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s48 Revegetation Planting techniques Final density, multi-stage, dense initial, or accelerated succession  Works well as a community stewardship project

49 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s49 Revegetation Other considerations Landscape connectivity to existing habitats Increase in woody debris could be positive How will nutrient cycles be impacted? Image: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by FISRWG.

50 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s50 Revegetation Management Vital to water plants Continue to control exotic species Consider impacts of herbivores Two years after planting

51 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s51 Stream restoration case study #2 Weminuche River, CO  Drains 30 mi 2 in southwestern Colorado  Shows how observation and understanding of stream classification and historical information helped set specific goals to create channel stability based on the stream type

52 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s52 Weminuche River, Colarado Impacts of 1978 riparian vegetation removal (government cost-share program increasing grazing areas) caused channel instability  Width/depth ratio increased form 14 to 35  Meander width ratio decreased from 10 to 2  Down valley meander migration rate increased approximately 8 feet/year  Increased sediment supply (erosion) and decreased transport capacity led to excessive bar deposition (aggradation)  Meander length and radius of curvature increased (sinuosity decreased)  Fish habitat and aesthetic values decreased  Poised to cut through banks to create new main channel

53 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s53 Weminuche River, Colorado  Funded as a mitigation  Goal of 1987 restoration  Return stream function and channel stability to benefit brook trout  Techniques  Recreated dimension, pattern, profile of a stable stream type  Studied pre-disturbance features, developed empirical relationships

54 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s54 Weminuche River, Colorado  Evaluation  Channel stability returned  Width/depth returned to 14  Slope from 0.01 to 0.005  Sinuosity returned to 2.0  Meander wavelength established at 10 bankfull widths  Meander radius of curvature at 2.8 bankfull widths  Willow transplanted along streambanks  Great example of considering stream morphology instead of just addressing bank erosion in small sections

55 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s55 Stream restoration case study #3  Merrimack River, New Hampshire & Massachusetts  Drains 5010 mi 2 in NH and MA flowing to the Atlantic Ocean  Demonstrates a watershed approach to stream restoration of point and non- point pollution

56 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s56 Merrimack River, MA and NH  Impact from human use  1930s contamination from pollutants such as raw sewage, paper mill waste, tannery sludge  Too polluted for domestic water supply uses  One of the 10 most polluted streams in nation

57 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s57 Merrimack River, MA and NH  Passing of the Clean Water Act of 1977 (water quality standards) and formation of the Merrimack Watershed Council brought about restoration actions:  84 wastewater treatment plants constructed  Majority (~85%) of industries complying with federal standards  Suspended solids decreased (by 1/3 in one reach), coliform bacteria and organic loading concentrations reduced, dissolved oxygen levels increased

58 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s58 Merrimack River, MA and NH  Future goals of the Merrimack Watershed Council  Improve the protection of present and future water supply  Improve water quality through…interagency cooperation on water quality issues  Continue work on flow issues  Promote growth management within the Watershed  Continue to improve access to the River and the acquisition of open space

59 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s59 Merrimack River, MA and NH  Evaluation  Good example of a watershed scale restoration with cooperation between multi- state agencies and organizations  Reminder that some industries still not in compliance with water quality standards set in 1977  Shift from a point pollution focus to non-point and water quantity issues

60 Developed by: Peichel, Reed Updated: 7/14/03 U6-m25-s60


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