Pike River Restoration Adaptive Design: Restoring Structure and Function in an Urban Floodplain - from cabbages to cordgrass Alice Thompson, PWS & Heather Patti, PWS
Pike River Re-imaginedfrom Cabbage to Cordgrass: The government tells us we need flood control and comes to straighten the creek in our pasture. The engineer on the job tells us the creek is now able to carry off more flood water, but in the process we have lost our old willows where the owl hooted on a winter night and under which the cows switched flies in the noon shade. We lost the little marshy spot where our fringed gentians bloomed. Aldo Leopold, The Round River, 1953
Phase 1 & 2 Phases 1-9 5.2 river miles
Phase 3 & 4
Phase 6-9
Phase 1 2003 Goals: Flood abatement Ecosystem services: prairie/wetlands/stream biodiversity shade, stability, structure, wildlife/fish habitat & conveyance
Newly graded soils 2003-04 native seed, root stock, coir logs, bare root shrubs & trees outside of floodway
2004-2006 planted bare root stock shade, stability, structure, conveyance
2004 algae mats inhibit shrubs buttonbush 6 years later
5-7 years to develop shade over stream 2005 2006 2011
Sand bar willow Phase 1 5 years and 8 years after installation Sandbar willow 2015 2009 2012
Prairie cordgrass
Trees and Time 2011 Bur Oak bare root stock planted 2004-7 years later Swamp white oak 1 year on Pike Green ash saved on bank -2 years post construction
Design Constraints within an Urban Setting Sewer/ water Methane Chlorine Payne & Dolan Steele Branch stormwater ATC corridor ATC corridor overhead- can not raise grade more than one foot need access to maintain lines (no wetland) Underground interceptor sewer line Exposed methane pipe Steele Branch Storm pipes on NW end (design weir to collect sediment ) Ditch with SC Johnson Cooling water (chlorine) Desire to manage stormwater with ponds /pike spawning /wildlife use
Phase 4: Concept Designs-stakeholders meeting- 2006
Phase 4 Implementation SCJ Cooling H2O Steele Branch
Sediment Trap Photo: Bill Sasse
1/2010 January, 2010
Phase 4 2015-5 + years after construction
50 % Design to 100 % Design ox-bow feature GW
Off line ox-bow 2009-2011 Repeated in Phase 6 B constructed in 2012
Phase 6 off line ox-bow August, 2013 March, 2013
Phase 6 low flow and flood stage
In stream Habitat Constraints Woody Structure/stability vs. Flood water Conveyance Because no trees in floodway, used: Shrubs Prairie cord grass/prairie grasses Wood in-stream habitat structures Rock & gravel for riffles Deeper fish habitat holes
2011 2009
2009 2010 burrito wrap banks 2011 Prairie seed Saved pocket of mature trees
Phase 8 Construction of fish habitat
Fish habitat in stream
Phase 7 Construction 2015 Before After After
Phases 8 & 9 Under Construction by Detroit District US Army Corps of Engineers
Phases 8 & 9 Under Construction
September, 2012 Prescribed burn April 2015 Management includes prescribed burns and herbicide control of targeted invasives September, 2015
Urban Recreational Trail
Summary Flood abatement issues were accomplished through an adaptive design process An ecological focus was prioritized within the constraints of an urban river corridor Now a highly valued recreational and ecological asset to the community
Acknowledgements Village of Mount Pleasant Stormwater Commission (Bill Sasse, Tony Beyer, Steve Houte, Sonny Havn) Dr. Timothy Ehlinger, UW-Milwaukee US Army Corps of Engineers Wisconsin DNR GAI Consultants, Inc.