progress report – design of native wetland nursery facility design of native wetland nursery...
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Progress Report – Design of Native Wetland Nursery Facility
For Metro’s Native Plant Center
Prepared by:Portland State Department of Civil and Environmental Engineering
Senior Design Class, 2009
Department of Civil and Environmental EngineeringSenior Design Class - 2009
2Native Wetland Nursery Design for Metro’s Native Plane Center
Project Overview• Native Plant Center is a Metro-operated nursery in Tualatin, OR• Located on south banks of Tualatin River• Cultivates native plants for Metro’s various habitat restoration projects• Project proposal is to expand the Native Plant Center by building a
wetland nursery facility in adjacent lot
ProposedWetlandNursery
Site
NativePlant Center
N
Department of Civil and Environmental EngineeringSenior Design Class - 2009
3Native Wetland Nursery Design for Metro’s Native Plane Center
Project Scope
• Design a series of shallow pools that will serve as planting beds for native wetland plants
• Supply pools using multiple water sources – surface runoff, Tualatin River water rights
• Pools will have overflow-protection system to guard against damage from extreme storm events
• Pools will have a water depth control system to accommodate growing requirements for different plant species
• Proposed facility must allow for access by personnel for planting and harvesting activities
• Cost will be significant in design considerations
Department of Civil and Environmental EngineeringSenior Design Class - 2009
4Native Wetland Nursery Design for Metro’s Native Plane Center
Feasibility Study
1. Survey – High resolution elevation contours, setback boundaries, water lines
2. Geotechnical – soil classification/distribution, water infiltration rates
3. Water runoff model – predict flow rates and volumes of water from various intensity storm events
4. Literature review – Overview current design provisions for constructed wetlands, relevant permitting issues and
constraints
Department of Civil and Environmental EngineeringSenior Design Class - 2009
5Native Wetland Nursery Design for Metro’s Native Plane Center
Survey
• Pools will be constructed by grading, requires high-resolution elevation data (elevation contours from Metro were insufficient for design)
• Survey conducted with Leica SmartPole™ GPS survey station– simple, quick alternative to total station survey– position resolution capable of 0.02 feet
(latitude, longitude, mean sea level) • Positions recorded then downloaded into
AutoCAD Land Development– Automatic generation of elevation contours from survey
data– Allow for 3D visualization of design and development of
grading plan
Department of Civil and Environmental EngineeringSenior Design Class - 2009
6Native Wetland Nursery Design for Metro’s Native Plane Center
Survey Results
Contours from Metro New GPS Survey Contours
10’ Contours 1’ Contours
Water linetie-ins
SepticSetback
Department of Civil and Environmental EngineeringSenior Design Class - 2009
7Native Wetland Nursery Design for Metro’s Native Plane Center
Geotechnical Investigation Field/Laboratory Tests• Soil samples for soil classification and compaction tests• Test infiltration rates on-site where pools will most likely be constructed
Infiltration Test Soil Sampling
Department of Civil and Environmental EngineeringSenior Design Class - 2009
8Native Wetland Nursery Design for Metro’s Native Plane Center
Geotechnical InvestigationResults• Soil is low-plasticity ML silt, uniformly
distributed• Measured infiltration rates –
0.052 in/min (sample A)0.058 in/min (sample F)
A
F
A
B
C
D
E
F
Soil collectionSites
(0 – 9 ft deep)
InfiltrationTests
Department of Civil and Environmental EngineeringSenior Design Class - 2009
9Native Wetland Nursery Design for Metro’s Native Plane Center
Surface Water Runoff Model• Pools will be supplied from
multiple sources – (water pump rights, runoff)
• Surface water runoff model will help establish how much water is available from storm events
• Surrounding areas were partitioned into different basins
• Rational model used to predict peak flowrates for 3 cases
Case I – runoff from Native Plant Center only
Case II – runoff from Native Plant Center and all surrounding areas
Case III – runoff from Native Plant Center and field to south
Model Case Basins
I 1, 2, 3, 4
II 1, 2, 3, 4, 5, 6, 7
III 1, 2, 3, 4, 7
Department of Civil and Environmental EngineeringSenior Design Class - 2009
10Native Wetland Nursery Design for Metro’s Native Plane Center
Surface Water Model - ResultsCase I - QLongest route
(time, min) 23.3 tc
i (in/hr) Q (cfs)Q2 0.9 2.37Q10 1.6 4.21Q50 2 5.26Q100 2.3 6.05
Case II - Q
Longest route (time, min) 41.4 tc
i (in/hr) Q (cfs)Q2 0.6 6.70Q10 0.9 10.05Q50 1.2 13.40Q100 1.5 16.75
Case III - Q
Longest route (time, min) 33.6 tc
i (in/hr) Q (cfs)Q2 0.7 2.79Q10 1.3 5.19Q50 1.6 6.39Q100 1.8 7.19
Department of Civil and Environmental EngineeringSenior Design Class - 2009
11Native Wetland Nursery Design for Metro’s Native Plane Center
Feasibility Summary• Survey –
– Elevation contours sufficient for grading design– Septic tank setback will prohibit construction of pool on north half of
proposal site• Geotechnical –
– Uniform soil type and distribution across site– Infiltration rates too high to allow for sufficient hydraulic residence
times for pool – amending soil with bentonite and soil compaction will be necessary
• Water Model – – Capture of water from neighboring sites may be costly and of low
quality– Predicted flow rates from Case I suggest that irrigation from Tualatin
River will be required to fill pools
Department of Civil and Environmental EngineeringSenior Design Class - 2009
12Native Wetland Nursery Design for Metro’s Native Plane Center
Tasks for Spring Term• Pool Design –
– Finalize specifications for decreasing infiltration rate (bentonite, compactions), Grading, overflow protection, water depth regulation, berm design
• Cost Estimates – – Addition of french drain for water runoff capture, irrigation piping,
possible on-site storage outside of pools• Final Proposal –
– Design drawings and specifications, budget, feasibility report
Class BeginsSite Plan - CADSpecificationsCost EstimationConstruction ScheduleConstruction BeginsConstruction ObservationClass Ends
Department of Civil and Environmental EngineeringSenior Design Class - 2009
13Native Wetland Nursery Design for Metro’s Native Plane Center
Special Thanks
• Marsha Holt-Kingsley – Metro Native Plant Center Coordinator• Brad Bogus, PE – Kennedy/Jenks Consultants• The survey guy <name>
Department of Civil and Environmental EngineeringSenior Design Class - 2009
14Native Wetland Nursery Design for Metro’s Native Plane Center
Questions?