Geomorphology of Lowland Streams and Implications for Restoration

Transcription

1 Geomorphology of Lowland Streams and Implications for Restoration Faith Fitzpatrick US Geological Survey, WI Water Science Center, Middleton, WI February 2015 Rock River Coalition Fitchburg, Wisconsin

2 Glacial landforms = >>>> stream diversity \ Late Glacial Wisconsin Till landforms (Tazewell and Cary in Iowa; Woodfordian in Wisconsin and Illinois) Iowan Erosion Surface Tazewell Till Terminal Moraine from older glaciation Loess- Covered Pre-Illinoian Glacial Till Iowan Erosion Surface; Mainly on pre-illinoian Glacial deposits Driftless Area Illinoian Till Source: JC Knox

3 Flood Hydrograph Examples

4 Urbanization Effects on Flood Peaks Flood Peaks in ft3/mi Pheasant Branch Spring Harbor Storm Sewer Yaraha River Black Earth Creek Years

5 Spring Harbor storm drain Aging urban drains that cause downstream water quality issues, sedimentation, degradation of important habitats, = barriers in all directions

6 Hydrologic Longitudinal and Lateral Connections P Overland flow converging into a hollow P P P P Saturated zones Pipeflow Groundwater flow (Charlton, 2008)

7 Sediment Sources and Sinks

8 Extension of drainage networks and aggradation Original channel New channel Aggradation/new alluvium Aggradation Drainage divide Tip of new channel Tip of original channel

9 Marshall Former Wetland Extent in 1890s East of Madison, Wisconsin, Near Marshall Note That Channelization Already Was Common in This Watershed Large Goose Lake Slide: J.C. Knox Koskonong Creek

10 Marshall Circa 1950 Wetland Extent, East of Madison, Wisconsin, Near Marshall Small Goose Lake Slide: J.C. Knox Koskonong Creek

11 Little Menomonee Creek Incision/Bank Erosion from Ditching

12 1836 Government Land Office (GLO) 18 links 18 links = 12 ft

13 Year and source Length (ft) 1930 s LEI 3, air photo 3, air photo 2, air photo 2,690 Overlay of Channel Locations

14 Elevation in feet above NAVD xs 28 north floodplain flood chute Little Menomonee Creek Cross sections spoil pile est. bankfull water surface Distance from left bank in feet south floodplain 2008 bankfull 1 ft below old floodplain spoil pile on south side about 3.5 ft high 2008 channel width 8-10 ft

15 East Fork Cranberry River (Coniferous swamp)` Lenawee Creek CR01 CR EAST FORK LENAWEE Drainage area (mi 2 ) Base flow (cfs) % forest % barren/shrub 5 9 Reach slope

16 Whittlesey Creek, 50 year old willows on the main stem Whittlesey Creek, local scour when old willows fail

17 Longitudinal Profile Comparisons Photo of Cranberry River, White Cedar swamp Whittlesey Creek Willow plantings photo

18 Similar sediment/channel morphology story for northern forests. Meters Post Euro-American settlement sandy alluvium Large woody debris Thick vertical accretion with little soil development and coarse-grained texture THEN AND NOW WISCONSIN Bark River (beaver dam washout) Photo from Dennis Pratt Pre-settlement peat 2.7 Low-flow water level Bad River lower main stem Photo: Marie Peppler Marengo River middle main stem 2003 flood Whittlesey Creek lower main stem 2005 flood

19 Bad River at USGS streamgage

20 Halfway Creek Overbank Sedimentation (Fitzpatrick et al., 2009)

21 WI Driftless Area Upper Mississippi River Halfway Creek (Fitzpatrick, et al. 2009) Historical sedimentation (and erosion) rates have decreased by an order of magnitude over the last 75 years because of widespread adoption of soil conservation practices

22 Grant River little lateral connection, great conduit for runoff Depositional terrace ~10-yr recurrence interval ~1.5-yr recurrence interval Grant River nr Burton, WI; September 2007 Photo: Jim Knox The bankfull channel contains the flows that have a recurrence interval of about 1.5 years. This is a practical approximation of the channel-forming flow that forms the framework for stable channel design (Rosgen, 1996).

23 Northern lowland stream morphology Middle Branch Escanaba River near Humbolt, MI USGS streamgage October 2009 Riffle Cross Section 96 95? ~1.5-yr recurrence interval Elevation (ft.) Distance (ft.)

24 Middle Branch Escanaba River, October 2009 longitudinal profile Arbitrary elevation, in feet Bank height varies by > 1 foot? Water Surface Slope = Riffle-riffle slope = BANKFULL WATER SURFACE THALWEG Longitudinal distance from u/s end of reach, in feet

25 Dead River Comparison Restored vs. Natural Which river is better? Which river is more resilient to climate change? Which river is more stable?

26 Natural channel design too much focus on channel as stable conduit rather than it lateral connections?

27 Runoff Channels Balancing River Forces (Bull, 1991, Geomorphic response to climate change, p. 15; Lane 1955)

28 Benefits from stream/riparian/palustrine vegetation interactions Palustrine wetland vegetation (USGS; etlands/classwet/palustri.htm) Moderate temperatures Provide large wood Provide organic matter/carbon Stabilize streambanks Reduce sediment inputs Filters nutrient and contaminants Provides food Shelter (year round) Slows flow Ponded water, nonerosive settings

29 Beaver dams North Shore Lake Superior, MN

30 Threats to Lowland Stream Ecosystems Ditching (stream network extension) Channelization/straightening Increased fine sediment and nutrients from upstream areas Decreases in water table elevations (drought, irrigation withdrawals, high capacity wells) Decreased longitudinal connectivity for channel and riparian (culverts) Decreased lateral connectivity (monotonous banks) Natural and artificial levees Decreased floodplain micro-topography Invasive species Urban runoff

31 NEH-653

32 Blanding s Turtle Emydoidea blandingii (photo bios.niu.edu) Female Blanding's turtles often nest in agricultural fields. Wetland complexes and adjacent sandy uplands are necessary to support viable populations of Blanding's turtles. Calm, shallow waters, including wetlands associated with rivers and streams, with rich, aquatic vegetation are especially preferred. The Blanding's turtle is a late maturing, long-lived species unable to recover quickly from catastrophic events that reduce the population (Congdon et al. 1993). Their relatively low mobility, high juvenile mortality rate, and low reproductive potential are also limiting factors for population growth. Loss and degradation of upland and wetland habitats, and mortality on roads are great threats to the species (Sajwaj et al. 1998).

33 Solutions to Broken Connectivity Reduce runoff and sediment from headwater/feeder tributaries Slow the flow in ditches and gullies Increase infiltration quench the thirst of shallow groundwater systems Reduce erosion -- repair incised, eroding gullies (sediment sources) Practice soil conservation in ag fields

34 Solutions to Broken Connectivity Reduce sediment and P from headwater/feeder tributaries Repair, install sediment retention structures Designate sacrificial areas in easy to maintain areas Halfway Creek, Experimental Wetlands, Jim Nissen, U.S. Fish and Wildlife Service

35 Solutions to Broken Connectivity Remove longitudinal barriers Fix culverts Daylight connector channels, especially those that are blocking key habitat niches for aquatic and riparian species (tweeners) Repair lateral connectivity Remove accumulated legacy sediment and ditch spoils Reoccupy meanders Restore stream bank microtopography Remove invasive and plant native species, especially conscious of transition areas

36 Base-flow systems instead of runoff channels Example--Atlantic White Cedar rehabilitation in Chesapeake Bay tribs Sometimes created over the top of existing legacy sediment Direct connection between stream and floodplain Minimal disturbance to existing riparian vegetation Promote sediment and organic matter deposition Transform nutrients into biomass Sequester carbon Ann Arundel County; Berg, Biohabitats; Inc.; Keith Underwood & Assoc.