sw solutions green infrastructure 2-day training in coos bay
TRANSCRIPT
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Stormwater Solutions Workshopin Coos Bay, OR on Feb 13 & 14, 2017
BROUGHT TO YOU IN PARTNERSHIP BY:
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
About MeMaria Cahill, Green Girl Land Development Solutions LLC
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
About Green Girl
Technical Writing/Editing, Graphics
Technical Assistance/Design Advice, Drafting
Workshops/Education & Outreach
Facilitation & Ecocharrettes
Construction Inspection (ODOT Certified)
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Low Impact DevelopmentLand Use Applicability
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Definitions: Low Impact Development
Low Impact Development is a pattern of land development that relies on a collection of techniques (aka Best Management Practices or BMPs, which are carefully selected) that preserve natural resources and collect and clean stormwater runoff to protect and improve water quality and availability.
Depending on BMPs, LID is great for resiliency (climate change, flooding, landslides, stream bank erosion, and saltwater intrusion).
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Definitions: Best Management Practice
The EPA defines a best management practice (BMP) as "a device, practice, or method for removing, reducing, retarding, or preventing targeted stormwater runoff constituents, pollutants, and contaminants from reaching receiving waters.”
Is there really a best BMP?
How many doyou see here?
At least 4: Vactor truck, green street, trees, narrow street
Nope!
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Site-scale Treatment Train
“Diverse and redundant systems are inherently more resilient.”1
1 Development Strategies for Promoting Coastal Resiliency & Sustainability
Minimize Impervious Area: Narrow street
Trees
Stormwater Planters in between trees?
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Choose the Best mix of BMPs for your site
BMP Suitability Matrix
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
BMP Suitability MatrixColumn Headings Close-Up
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Annual Water Balance Model: A Framework forWatershed Health, BEFORE Development
25% baseflow(infiltration)
50%
ev
apo-
tran
spira
tion
0.5% runoff
100%
ave
rage
An
nual
rain
fall
25%
gro
undw
ater
(infil
trati
on)
HERE INWESTERN OREGON
National average = 5%
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Annual Water Balance AFTER DevelopmentExample: EVERYWHERE
0” baseflow(infiltration)
redu
ced
evap
o-tr
ansp
iratio
n
100%
rain
fall
year
ly a
vg98% runoff
2% e
vapo
-ra
tion
Redu
ced
infil
trati
on
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
“Before” & “After” Runoff Compared
0.5% runoff
98% runoff
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Runoff Volumes: A Watershed Perspective
Natural WatershedUrbanized or Working Landscape Watershed
Slide from Stamberger Outreach Consulting
= HYDROMODIFICATION
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
LID BenefitsRunoff Volume from a Watershed Perspective
Erosion ->
Turbidity ->
Impacted Habitat ->
Very Real Recreational & Economic Impacts
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Water Quality BEFORE Development
Some sediment
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Water Quality AFTER Development
Sediment (air particulates)Nutrients
FecesOther debris
Runoff volume
Sediment/turbidityHydrocarbons
Heavy metals (particles & soluble)Other chemicalsRunoff volume
Sediment/turbidityfertilizerspesticidesherbicides
Runoff volume
16
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Real Community Value
http://bit.ly/GC-GH “Social equity and community contribute to resilience.” 1
1 Development Strategies for Promoting Coastal Resiliency & Sustainability
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Stormwater HierarchyLevel 1
1. Lay out the site to minimize impacts to natural resources and to minimize impervious areas (Runoff Prevention).
Courtesy of NEED Development
“Simple, passive, and flexible systems are more resilient. 1
1 Development Strategies for Promoting Coastal Resiliency & Sustainability
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Minimize Impervious Area: Shared Parking Spaces BMP
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Photo credit: Joseph Dewey
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Minimize Impervious Area: Minimize Pavement Widths BMP
Oregon Department of Land Conservation and Development’s Model Development Code for Small Cities (Smart Growth principles included!): ttp://www.oregon.gov/LCD/TGM/pages/modelcode.aspx4
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Minimize Impervious Area: Minimize Front Setbacks BMP
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Minimize Impervious Area: Share a Driveway BMP
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Minimize Impervious Area: Minimize Building Footprints BMP
Great example: Not ALL BMPs suitable for ALL stakeholders
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Minimize Impervious Area: Minimize New Pavement BMP
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Limit Disturbance: Construction Sequencing BMP
Starts in planning!
Protects soil resources by preventing compaction
Includes:Fencing! Fencing! Fencing!Haul roadsPhasing clearing & constructionCommon setbacksEquipment & grading choices
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Conserve Fast(er) Draining Soils BMP= Infiltration Testing
For protected and developed areas. Infiltration testing needed for:•Cluster Development BMP•Porous Pavement (Runoff) BMP•Infiltration Rain Garden or LID Swale BMP•Infiltration Stormwater Planter BMP•Drywell BMP•Soakage Trench BMP•Vegetated Filter Strip (VFS) BMP•Downspout Disconnection BMP
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Limit Disturbance: Conserve Fast(er) Draining Soils BMP
Infiltration rate in inches per hour
Guides site layout and where other BMPs are located
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Limit Disturbance: Cluster Development BMP
Courtesy of AHBL
“Resilience transcends scales.”1
1 Development Strategies for Promoting Coastal Resiliency & Sustainability
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Consider connectivity
“Resilience transcends scales.”1
1 Development Strategies for Promoting Coastal Resiliency & Sustainability
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Limit Disturbance: Tree Protection BMP
Individual tree LOTS of ways to kill a tree in “Pitfalls and Common Mistakes”
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Limit Disturbance: Minimal Foundations BMP
Great for flood prone areas and high groundwater tables
Photo courtesy of Taylor White, Flickr
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Limit Disturbance: Minimal Foundations BMP
In Massachusetts, one study found significant NFIP savings to a particular approach
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
Development Strategies for Promoting Coastal Resiliency and Sustainability
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Limit Disturbance: Minimal Foundations BMP
Hierarchy Level 1: Lay out site to minimize impervious area and limit disturbance
FEMA’s Homeowner’s Guide to Retrofitting
One sea level/climate adaptation method: Flow through basements
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Stormwater HierarchyLevel 2
2. Prevent runoff by intercepting, evaporating, and/or infiltrating rainfall. (Runoff Prevention)
Step 2 Intercept runoff and evaporate and/or infiltrate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Water Quality and Land UseWhy Runoff from Lawns Cannot be Ignored
Courtesy of Pat Lando, Lando Landscape Architects
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Water Quality and Land UseWhy Runoff from Lawns Cannot be Ignored
Created Table 8-1 of the Pennsylvania Stormwater Best Management Practices Manual & Table B5 of Center for Watershed Protection publication “Urban Stormwater Retrofit Practices”
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Restored Soil BMP
REQUIRED on every new and re-development in Western WA. Great for retrofits, too (see left)
Hierarchy Level 2: Intercept runoff and evaporate and/or infiltrate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Restored SoilLawn Areas
from Soils for Salmon website
Hierarchy Level 2: Intercept runoff and evaporate and/or infiltrate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Restored Soil BMPPerennial Garden Areas
Hierarchy Level 2: Intercept runoff and evaporate and/or infiltrate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Revegetating Everywhere
Courtesy of Serena (Flickr)
Hierarchy Level 2: Intercept runoff and evaporate and/or infiltrate
Salt tolerant vegetation stabilizes fill added to address bank erosion.Photo: MA Office of Coastal Zone Management.
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Depaving Existing Pavement BMP
DURING
AFTER
Hierarchy Level 2: Intercept runoff and evaporate and/or infiltrate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Contained Planters BMP and Vegetated Roofs BMP
Step 2 Intercept runoff and evaporate and/or infiltrate
Hierarchy Level 2: Intercept runoff and evaporate and/or infiltrate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Vegetated Roofs Monitoring
This roof is only 69% covered, yet peak flow reduction (i.e. flood storm management) is 96% annually!
City of Portland’s 2013 Monitoring Report
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Porous Pavement BMP
Port of Portland installed 35 acres of porous asphalt
Hierarchy Level 2: Intercept runoff and evaporate and/or infiltrate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Porous Pavement BMPHierarchy Level 2: Intercept runoff and evaporate and/or infiltrate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Stormwater HierarchyLevel 3
3. Reduce runoff using BMPs with surface storage (i.e. ponding) that infiltrate and to a lesser extent, intercept and evaporate runoff and the rainfall they receive.
Remain
ing runoff
“Find and promote resilience in nature. 1
1 Development Strategies for Promoting Coastal Resiliency & Sustainability
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
One Term for 3 BMPs: Vegetated Stormwater Facilities
Includes Rain Gardens, LID Swales, & Stormwater Planters PRIMARILY BECAUSE they all have pond storage (i.e. “ponding”)
“Locally available, renewable, or reclaimed resources are more resilient.” 1
1 Development Strategies for Promoting Coastal Resiliency & Sustainability
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Rain Garden BMPHierarchy Level 3: Reduce runoff with ponding facilities that infiltration AND evaporate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
LID Swale BMPHierarchy Level 3: Reduce runoff with ponding facilities that infiltration AND evaporate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Stormwater Planter BMPHierarchy Level 3: Reduce runoff with ponding facilities that infiltration AND evaporate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Sizing Facilities for Climate ChangeHierarchy Levels 3 - 6
“Resilience anticipates interruptions and a dynamic future. 1
1 Development Strategies for Promoting Coastal Resiliency & Sustainability
Excel Models Available on the Stormwater Solutions Website•SBUH shape, but calculates peak flows over 10 minutes periods using the rational method. •Then volumes are infiltrated based on design storm, infiltration rate, and facility size•NOT ALL BMPS REQUIRE HYDROLOGIC MODELING
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Elements of LID for Ponding BMPsBMP-Scale Treatment Train: One Example
2 Pretreatment inlet basin captures
sediment and slows flows/reduces
erosion
Old Pretreatment inlet left in place, but could’ve been
removed after 2 was installed.
COMMON BUT NOT RECOMMENDED! HIGH
MAINTENANCE!
3 – 6 Rain garden treats and infiltrates runoff
1 Drainage area is swept regularly & is
maintained with coal-tar free asphalt
sealant
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
High Flow Bypass
1. Runoff flows into
inlet
2. Runoff fills stormwater
planter
3. Water backs up to this gutter elevation
4. Runoff bypasses to
next available facility
“Simple, passive, and flexible systems are more resilient.” 1
1 Development Strategies for Promoting Coastal Resiliency & Sustainability
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Safe Overland Route for the Very Large Storm
GREAT to see what a
safe overland
route!
HORRIBLE example of a
dispersion BMP!
• The term means a location where flows won’t go very often (i.e only during very large storms) and will protect infrastructure from damage.
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Stormwater HierarchyLevel 4
4. Reduce runoff using BMPs with underground storage that infiltrate runoff.
Remain
ing runoff
Hierarchy Level 4: Infiltrate runoff underground
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Porous Pavement (Runoff) BMPSizing Infiltration Facility
Roof area and sidewalks drain to rock trench below porous pavement
Porous Pavement
Extent of additional rock trench to manage runoff from roof and
sidewalks
Hierarchy Level 4: Infiltrate runoff underground
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Porous Pavement (Runoff) BMP
Siting and sizing of porous pavement (runoff)
•=
Siting and sizing of other infiltration facilities like rain
gardens
=
Hierarchy Level 4: Infiltrate runoff underground
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Porous Pavement (Runoff)Grants Pass Porous Pavement Demonstration
Take it away William Fletcher!
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Drywell BMP
Different infiltration rates likely to occur throughout depth. This is an Underground Injection Control.
Photo courtesy of Howard’s Excavating, New Buffalo, MI
Hierarchy Level 4: Infiltrate runoff underground
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Soakage Trenches BMPHierarchy Level 4: Infiltrate runoff underground
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Stormwater HierarchyLevel 5
5. Reduce runoff using flow-based BMPs without storage (i.e. conveyance) that infiltrate lower volumes and to a lesser extent, intercept and evaporate runoff and the rainfall.
runoff
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
WQ Conveyance Swale BMP
Flow based facility requires modeling by a qualified licensed engineer.
Hierarchy Level 5: Mostly treat water, but some might infiltrate and evaporate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
WQ Conveyance Swale BMP
WQ Conveyance Swale is NOT:
Hierarchy Level 5: Mostly treat water, but some might infiltrate and evaporate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Dispersion: Vegetated Filter Strip BMP
ODOT developing sizing method for infiltration. Currently only limited infiltration,mostly treatment.
Hierarchy Level 5: Mostly treat water, but some might infiltrate and evaporate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Dispersion: Vegetated Filter Strip BMP
Photo courtesy of WADOT
Hierarchy Level 5: Mostly treat water, but some might infiltrate and evaporate
ODOT has a new methodology for this.
Take it away William Fletcher!
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Dispersion: Downspout Disconnection BMP
Lots of meaningless and unvetted ways have been tried in Portland:
Hierarchy Level 5: Mostly treat water, but some might infiltrate and evaporate
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Stormwater HierarchyLevel 6
6. Improve the water quality of runoff, without significantly reducing the volume, using a lined BMP or proprietary device.
runoff
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Stormwater Planter BMPHierarchy Level 6: Only treat water (Infiltration and evaporation volume little to none.)
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Lined Vegetated Stormwater BMPs
Photo courtesy of Lee Munson, City of Portland
Hierarchy Level 6: Only treat water (Infiltration and evaporation volume little to none.)
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Creating an LID Project
Low Impact Development is an iterative process.
Collaboration during the entire process can reduce costs significantly!
Stormwater Solutions Workshop –Coos Bay, OR - Feb 13, 2017
Maria CahillPrincipal & Green Infrastructure Consultantc [email protected] Certified Women Business Enterprise (WBE) & a Registered Benefit Company in Oregon
Thank You for Your Attention!