Post on 18-Aug-2015
Who we are Nancy Rottle - Director, University of Washington
Green Futures Research and Design Lab Mason Bowles - Senior Ecologist, Ecological Restoration
and Engineering Services Section, WLRD Matt MacDonald - Student, UW Masters of Landscape
Architecture Program; Staff Member, UW Green Futures Lab
Sally Abella – Senior Engineer, Freshwater Assessment
Group, Science and Technical Support Section, WLRD
Floating Wetlands presentation outline
• What are floating wetlands?
• Why do they matter?
• How do they work?
• Where are they already?
• How is King County involved?
• Where else could they be used?
What are floating wetlands? Constructed ecosystems that mimic naturally occurring wetlands
biomatrixwater.com naturalhighsafaris.com
In some cases, they are naturally occurring wetlands, e.g. bogs
Evans Creek, Redmond
What are floating wetlands? Constructed ecosystems that mimic naturally occurring wetlands
Floating Island International
British Library
Hicklin Lake, West Sea0le
Photo: Matt MacDonald
Floating frame or foam mat
Growing media
Native wetland plants
Andrea Haynes
• Sequester carbon • Improve water
quality
• Create habitat
• Tolerate fluctuating water levels
• Can be configured to existing aquatic urban environments
Andrea Haynes
Why are floating wetlands an important new technology?
• Improves water quality and provides habitat
• Scalable and cost effective with minimal maintenance
• Can be configured to existing urban and rural aquatic environments
• Increases wetland area without requiring additional land
Why are floating wetlands an important new technology?
• Improves stormwater pond polishing efficiencies
• Not compromised by water level fluctuation
• Relies upon biotic processes to manage pollutants (biofilms)
• An innovative BMP gaining broader acceptance
Spiral Island 1, Joyxee, Mexico
What are the shortcomings of floating wetlands?
• Lower dissolved oxygen (DO) may occur underneath mats
• Sizing criteria still being refined
• Organic litter needs to be removed if managing for nutrients
• May attract waterfowl
• More frequent stormwater pond sediment removal
What are the immediate benefits of floating wetlands?
• Increases aquatic shading • Traps sediments • Competes for nutrients • Mitigates metals and toxicants • May control temperatures • Contributes to food chain • Provides habitat complexity
What are the long-term benefits of floating wetlands?
• Shoreline protection
• Habitat restoration
• Beautification
• Water quality improvement
• Climate adaptation and mitigation
Water Quality Improvement
Floating Island International
Biofiltration: Water Quality Improvement
Floating wetlands: • Reduce total suspended solids (turbidity) • Reduce total phosphorous • Reduce ammonia • Reduce total nitrogen • Reduce bio-chemical oxygen demand (BOD) • Remove heavy metals
References- tinyurl.com/FloatingWetlandsSeattle
Plant and Insect Habitat
pichost.me/1620939/
Fish Habitat
Floating Island International
Wildlife Habitat
Floating Island International
Shoreline Protection
Floating Island International
Climate Adaptation and Mitigation
Floating Island International
Beautification
Turenscape
Shade & Cover
Turenscape
BioMatrix
Shoreline Restoration
Installed
Mature
How do floating wetlands work?
tinyurl.com/FloatingWetlandsSeattle
Some Literature Reports
What do floating wetlands cost?*
• Port of Vancouver, WA $0.85 sq. ft. • KCDOT Lower Stensland Creek $1-14 sq. ft. • Phytolinks $20 sq. ft. • Biomatrix $32 sq. ft. • Biohaven $40+ sq. ft.
*not including costs of design, permitting,
maintenance, and monitoring
Where are floating wetlands already in use?
Worldwide Distribution
Yingri Lake, Jinan, China
Floating Island International
Queensland, Australia
SPEL Environmental
Louisiana Gulf Coast
Floating Island International
Baltimore Harbor
The Waterfront Partnership, photo by Adam Lindquist
Baltimore Harbor Proposal
San Francisco
Andrea Haynes
Opportunities Study
Andrea Haynes
Pacific Northwest
Port of Vancouver, WA (2015)
Matt Graves
Hicklin Lake, West Seattle (2013)
Photo: Matt MacDonald
Floa>ng water quality islands in Hicklin Lake, White Center
Sally Bartley Abella Science and Technical Support Section King County Water and Land Resources Division
Where is Hicklin Lake and its islands?
|
A brief(!) history of Hicklin (Hicks, Garre0) Lake: • Open water wetland dredged for storage capacity for golf course in the 1930s.
• King County purchased in the 1940s and created Lakewood Park, including swim beach and fishing dock.
• Combined sewer system split into two systems in late 1950s – old lines used for storm water and rerouted into Hicklin Lake.
• High bacterial counts found in the 1960s beach closed recurrently; becoming permanent in 1991.
• Flooding during winter storm events. Pump installed to control water levels; water goes to Puget Sound.
• WDFW fish stocking ended in 1992. Dock dismantled 2012.
• Nuisance and toxic algae concerns result in first alum treatment in 2005, followed by a second treatment in 2011. Floa>ng islands in 2013.
Floa>ng islands project – the dry details: • Friends of Hicklin Lake asks for floa>ng islands as an alterna>ve to future alum treatments.
• Island suitability was inves>gated: water quality benefits, habitat enhancement, costs, maintenance.
• Funding leveraging a WDOE algae control grant with supplementary King County project funding, affording two islands of 600 a2 each and WQ monitoring for two years.
• Biomatrix Water / Herrera Environmental selected to provide pladorms and direct installa>on in July 2013.
• Plan>ng design by King County staff, combining sedges, rushes, and bulrush with willows and na>ve ornamentals such as Nootka Rose, Ninebark and red-‐twig dogwood. (FOHL request : make them pre0y!)
Installa>on: a community event • King County staff and contractors, • Washington Conserva>on Corps team, • KC Youth Source interns, and • University of Washington students
The lake level was LOW! Note lack of emergent vegeta>on around shoreline.
Installa>on: anchoring in place
Maintenance and lessons learned: • Annual weeding in late spring sufficient; check-‐back in fall. • Mortality less than 10%, mostly small sedges planted high. • The shrubs will need to be pruned regularly. • Blown-‐in weeds can establish quickly. • As the plants grow, it’s harder to maintain the plants … need chest waders to get on the islands.
• Ducks deterred by fencing, but do rest on the edges. • Kids throw rocks! Center placement helps.
Water quality monitoring: Important dates: April 2005 first alum; May 2011 second alum; July 2013 floa>ng islands
Dynamic media columns: • Inert material to create underwater surface area like root
systems. • Can remove and squeeze material off to measure N and P content. • One column from each island, June and September in 2014. • Measurements from one column in Fall 2013 produced similar
values. • NOTE: Observa>on of large root systems at the edges suggest
that more biofilm may be on living roots than on the columns.
Total N Total PEast island 6/10/2014 11.85 1.67
9/16/2014 66.56 10.24Increase % 562 613
West island 6/10/2014 9.94 1.379/16/2014 54.75 8.71Increase % 551 635
Total mg / media column
Metals and water quality standards:
exceeds or could exceed acute standardexceeds or could exceed chronic standard
0.50 red, bold font indicates <MDL
A745-‐1m Element 5/14/13 6/11/13 7/8/13 8/20/13 9/17/13 10/15/132013 hardness 20.3 21.4 22.1 20.8 21.2 18.5
pH 6.58 6.82 7.6 9.29 6.72 6.74 2013Deg-‐C 18.4 20.8 24.0 22.8 19.5 12.0 > chronic > acute median
Arsenic As 1.36 1.75 2.31 3.03 2.63 1.53 0% 0% 2.31Cadmium Cd 0.05 0.05 0.05 0.05 0.05 0.05 0% 0% 0.05Chromium Cr 0.38 0.34 0.37 0.31 0.40 0.44 0% 0% 0.37
Copper Cu 4.17 3.03 3.97 3.05 3.92 4.29 60% 40% 3.92Lead Pb 2.63 2.83 2.82 3.04 2.8 2.17 100% 0% 2.82
Nickel Ni 0.92 0.88 1.25 0.82 0.99 0.98 0% 0% 0.98Selenium Se 0.50 0.50 0.50 0.50 0.50 0.50 0% 0% 0.5
Silver Ag 0.04 0.04 0.04 0.04 0.04 0.04 0% 0% 0.04Zinc Zn 24.1 21.1 27.6 6.74 21.6 25.7 20% 0% 21.6
Element 5/13/14 6/10/14 7/15/14 8/19/14 9/16/14 10/14/142014 hardness 21 21.5 22.6 22.3 21.4 20.7
pH 7.79 7.31 7.24 9.26 7.38 6.18
Deg-‐C 17.8 21.4 25.4 23.4 18.6 16.1 > chronic > acute median change
Arsenic As 0.847 1.16 1.72 2.14 2.18 1.83 0% 0% 1.83 <Cadmium Cd 0.05 0.05 0.05 0.05 0.05 0.05 0% 0% 0.05
Chromium Cr 0.33 0.29 0.23 0.23 0.33 0.32 0% 0% 0.29 <Copper Cu 3.65 3.08 2.86 3.53 3.13 3.10 60% 0% 3.10 <Lead Pb 1.23 1.3 1.31 1.24 1.95 1.69 100% 0% 1.31 <Nickel Ni 0.804 0.78 0.66 0.67 0.62 0.765 0% 0% 0.67 <Selenium Se 0.50 0.50 0.50 0.50 0.50 0.50 0% 0% 0.5Silver Ag 0.04 0.04 0.04 0.04 0.04 0.04 0% 0% 0.04
Zinc Zn 25.9 7.6 10.8 8.43 9.83 9.27 0% 0% 9.27 <
% above standardJune-‐October
June-‐October% above standard
Future of the project and the islands: • Recently catalogued as a KC stormwater facility. • Remove tenacious reed canary grass plant: drowning and black
plas>c? • Monitor water quality into the near future to clarify direc>onal
changes from year-‐to-‐year variability. • Follow biofilm nutrient sequestra>on on dynamic media columns. • Sample root mass for biofilm nutrients? • Evaluate planted species for ul>mate size, growth rate, and ease
of maintenance. • Evaluate island structural components for longevity and durability. • Add to our Frisbee and rock collec>ons.
KCDOT Novelty Hill Road Improvement Project
Lower Stensland Creek Wetland Mitigation
• Created 2,912 linear feet of stream channel and 3.45 acres of riverine wetlands
• Installed 3.3 acres of native riparian and wetland buffer vegetation
• Created 0.25 acres of permanent open water • Deployed 1800 sq. ft. of floating wetlands
(.04 acres)
Lower Stensland Creek, Redmond, WA
Stensland Pond Preliminary Temperature AnalysisJuly 11, 2007
00:00:00 06:00:00 12:00:00 18:00:00 00:00:00
TEM
PE
RA
TUR
E (o C
)
14
16
18
20
22
24
26
28
30
32Stensland CreekWest Pond UpperWest Pond LowerModel - No shade Model - 25% Shade Model - 50% Shade
QUAL2K Temperature Model
• Model predicted that project with no shade would increase downstream temperatures by 4.3 oC at the outlet of the pond network for daily average temperatures
• With 25% shade, model predicted increases of 0.8oC • With 50% shade, model predicted decreases of 3.1oC
MacDonald Floating Wetlands Thesis, Redmond, WA
(in progress)
Thesis Goals sampler
• Design floating wetlands to mimic a greater array of wetland conditions and habitats
• Test Pacific Northwest plants for suitability
• Design FWs for lasting nutrient and carbon storage
First Prototype
Matt MacDonald
Shoreline Edge
Matt MacDonald
Emergent Vegetation
Matt MacDonald
Fully Submerged
Matt MacDonald
Fully Submerged
Matt MacDonald
Fully Submerged
Matt MacDonald
Overhanging Canopy
Matt MacDonald
Overhanging Canopy
Matt MacDonald
Overhanging Canopy
Matt MacDonald
PNW Plant Species
Matt MacDonald
~30 species used to date
Lasting Nutrient Storage
Matt MacDonald
harties.za.org
Lasting Nutrient Storage
Matt MacDonald
Open Water (Oxygen Exchange)
Matt MacDonald
How is the University of Washington involved with
floating wetlands?
Green Futures Lab
Urban Shorelines
Past Present Future
Matt MacDonald
Where might King County use floating wetlands?
• Detention ponds and water quality treatment • Urbanized wetlands • Hardened shorelines • Levies (trees no longer permitted)
Matt MacDonald
depts.washington.edu/wet/
Why do floating wetlands matter?
• Provide wetland functions, structures and processes
• Can be configured to existing aquatic environments
• Scalable and cost effective
“The best way to predict your future is to create it.”
-Abraham Lincoln
Questions?
Mason Bowles Professional Wetland Scientist Mason.Bowles@kingcounty.gov Sally Abella Senior Engineer, Limnologist Sally.Abella@kingcounty.gov Nancy Rottle Assoc. Professor, Director of Green Futures Lab nrottle@uw.edu Matt MacDonald floating wetlands enthusiast and designer macdon.matt@gmail.com
tinyurl.com/FloatingWetlandsSeattle (lots of links and other goodies!)
Matt MacDonald
Matt MacDonald
Overhanging Canopy
Matt MacDonald