PROGRAM OVERVIEW
• 2012: Public and private
partners engage state
legislature to fund program
• June 2012: LID Training
Steering Committee convened
• 2012‐2013: Washington State
LID Training Plan developed:
www.wastormwatercenter.org/
lid‐background
• 2014: Training program built
from state LID Training Plan
PROGRAM OVERVIEW
• 49 trainings in western and
eastern WA in 2014‐2015.
• 42 trainings in western and
eastern WA in 2015‐2016.
• 39 trainings offered in
western and eastern WA in
2017.
• Three levels: Introductory,
Intermediate, and Advanced.
• Statewide LID Certificate now
available.
PROJECT LEAD
ADDITIONAL TRAINING SUPPORT
OVERVIEW OF PROGRAM
CORE TEAM
Introduction to LID
for Inspection &
Maintenance Staff
INTRODUCTORY
INTERMEDIATE
ADVANCED
Intermediate LID
Design: Rainwater
Collection Systems &
Vegetated Roofs
Intermediate LID
Topics: NPDES Phase
I & II Requirements
Intermediate
LID Design:
Permeable Pavement
Intermediate
LID Design:
Hydrologic Modeling
Advanced Topics in
LID Design:
Bioretention
Advanced Topics in
LID Design:
Permeable Pavement
Advanced Topics in
LID Design:
Hydrologic Modeling
Advanced Topics in
LID Design: Site
Assessment,
Planning & Layout
Advanced Topics in
LID Design: Rainwater
Collection Systems &
Vegetated Roofs
Advanced Topics in LID
Design: Bioretention
Media and Compost
Amended Soils
OVERVIEW OF PROGRAM
Advanced Topics for
Long‐term LID
Operations:
Bioretention
Intermediate
LID Design:
Bioretention
Advanced Topics for
Long‐term LID
Operations:
Permeable Pavement
Intermediate LID
Design: Site
Assessment, Planning
& Layout
Introduction to LID
for Inspection &
Maintenance Staff
INTRODUCTORY
INTERMEDIATE
ADVANCED
Intermediate LID
Design: Rainwater
Collection Systems &
Vegetated Roofs
Intermediate LID
Topics: NPDES Phase
I & II Requirements
Intermediate
LID Design:
Permeable Pavement
Intermediate
LID Design:
Hydrologic Modeling
Advanced Topics in
LID Design:
Bioretention
Advanced Topics in
LID Design:
Permeable Pavement
Advanced Topics in
LID Design:
Hydrologic Modeling
Advanced Topics in
LID Design: Site
Assessment,
Planning & Layout
Advanced Topics in
LID Design: Rainwater
Collection Systems &
Vegetated Roofs
Advanced Topics in LID
Design: Bioretention
Media and Compost
Amended Soils
OVERVIEW OF PROGRAM
Advanced Topics for
Long‐term LID
Operations:
Bioretention
Intermediate
LID Design:
Bioretention
Advanced Topics for
Long‐term LID
Operations:
Permeable Pavement
Intermediate LID
Design: Site
Assessment, Planning
& Layout
Intermediate Site Assessment,
Planning and Layout
WESTERN WASHINGTON
Training Program
Statewide LID
INSTRUCTORS
JASON KING, RLA
ASLA LEED AP
Senior Landscape Architect
Key project experience: Stormwater design
for development, site design, green roofs,
stormwater art, ecological planning
DUSTIN ATCHISON, PE
Water Resources Project Manager
Key project experience: LID design, stormwater
master planning, stream and wetland restoration
design, hydrologic and hydraulic modeling
CURTIS HINMAN
Senior Scientist
Key project experience: Research
specialist in the performance and
design of LID practices.
AGENDA
introduction and regulations
345
LID site design process
site assessment and layout
site planning and infrastructure
exercises
trees
principles of LID site design
wrap up
AGENDA
introduction and regulations
345
LID site design process
site assessment and layout
site planning and infrastructure
exercises
trees
principles of LID site design
wrap up
LEARNING OBJECTIVES
1. Participants gain an intermediate level
understanding of overall site assessment with
particular attention to infiltration capability of
soils for roadway, lot and open space layout
within the LID context.
2. Participants gain an intermediate level
understanding of appropriate layout for
roadway, lot and open space to protect site
hydrology and create livable and attractive
developments.
3. Participants will gain an intermediate level
understanding of techniques to protect native
soil and vegetation during site development.
LOGISTICS
SCHEDULE
• 8‐hour training with two
breaks
• Lunch on your own
• Sign in and sign out
OTHER LOGISTICS
• Restroom location
• Food
• Turn off cell phones
• Q&A at end of each section
LID Principles: Pre‐developed forest
INTRODUCTION & REGULATIONS
2012 LID Technical Guidance Manual for Puget Sound
LID Principles: Developed condition
INTRODUCTION & REGULATIONS
2012 LID Technical Guidance Manual for Puget Sound
LOW IMPACT DEVELOPMENT (LID):
Stormwater Management Strategy
INTRODUCTION & REGULATIONS
• Site design & planning techniques
emphasizing conservation
• Use of small‐scale & distributed
engineered controls to closely mimic
pre‐development hydrologic processes
• Minimizing the concentration of
stormwater
• Careful assessment of site soils and
strategic site planning to best use those
soils for stormwater management
LID Principles: Site Design And Planning
INTRODUCTION & REGULATIONS
• Minimize disturbance
• Reduce impervious
surface
• Protect and restore
native soils and
vegetation
• Manage stormwater
close to the source in a
system of distributed
practices
• Disconnect impervious
surfaces
Traditional
LID
LID BMPs: Small‐Scale Engineering Controls
INTRODUCTION & REGULATIONS
• Infiltration
• Filtration
• Storage
• Evaporation
• Transpiration
Synonyms for LID BMPs:
Green Stormwater Infrastructure (GSI), Integrated Management Practices (IMPs), and On-Site Stormwater Management BMPs
Conserve or regain
pre‐developed hydrologic
functions
Western WA NPDES Permit
National Pollutant Discharge Elimination System (NPDES) Municipal Stormwater
Permits (2013‐2018 permit cycle)
Municipal Stormwater Permittees in Washington State
Phase 1 Permittees
Western Washington Phase
II Permittees
Eastern Washington Phase II
Permittees
Seattle
Tacoma
Clark County
King County
Pierce County
Snohomish County
82 Cities
5 Counties
18 Cities
5 Counties
Secondary Permittees: Approximately 45; such as ports and universities
To see a listing of permittees visit
http://www.ecy.wa.gov/programs/wq/stormwater/municipal/MuniStrmWtrPermList.html
INTRODUCTION & REGULATIONS
NPDES PERMIT LID REQUIREMENTS:
Implementation Timeline Varies By Permittee
INTRODUCTION & REGULATIONS
Review and revise development related codes, rules & standards (i.e. adopt the
2012 Stormwater Manual)
Timeline for updating local codes
Phase I
Per Section S5.C.5.b of
the Phase I Permit
Phase II
June
2014
June 30,
2015
Dec. 31,
2016*
June 30,
2017
June 30,
2018
Most
Permittees
Lewis Co. and
Cowlitz Co.
City of
Aberdeen
Per Section S5.C.4 of the Phase II Permit
* = Or GMA update deadline
Onsite SW Management BMP
Flow Control
Credit
Treatment
Credit1
Soil Amendment
Dispersion
Retaining & Planting Trees
Rainwater Harvesting
Bioretention3
Permeable Pavement3
Vegetated Roofs 3
DEFINITIONS
Subset of On‐site Stormwater Management BMPs used to meet MR #6 or MR #7
(may also be used to meet MR #5)
1 Meets basic, enhanced and phosphorus treatment when infiltrating through soil per Ecology treatment requirements
2 Where permeable pavement is over soils meeting the suitability criteria or a treatment layer is included
3Also considered SW Treatment & Flow Control BMPs/Facilities (additional requirements in regard to long term
inspection, operations, and maintenance apply)
INTRODUCTION & REGULATIONS
Q&A
1/26/15
AGENDA
introduction and regulations
345
LID site design process
site assessment and layout
site planning and infrastructure
exercises
trees
principles of LID site design
wrap up
The typical construction approach is to strip, cut,
fill and pound.
PRINCIPLES OF LID SITE DESIGN: Conventional
Site Development Practices and Impacts
• Compaction can extend 24”+ with
heavy loads on wet soils.
• Compaction usually in top 6‐8
inches of soil for tractors weighing
less than 10 tons/axle.
• Track vs tires inflated to higher
pressures…compaction appears to
increase with increased tire
pressure.
PRINCIPLES OF LID SITE DESIGN: Conventional
Site Development Practices and Impacts
U of Missouri and Minnesota Extension
Management of large clearing and grading operations is expensive
and time consuming.
PRINCIPLES OF LID SITE DESIGN: Conventional
Site Development Practices and Impacts
and Impacts
PRINCIPLES OF LID SITE DESIGN: Conventional
Site Development Practices and Impacts
• Stream biota significantly
reduced at SS levels of 50‐80
mg/L (Corish 1995).
• Schueler reported median TSS
concentrations of 4,145 mg/L
leaving construction sites with no
TESC and 283 mg/L with TESC.
PRINCIPLES OF LID SITE DESIGN: Value of
Native Soils and Vegetation
• 23.92 acres
• 103 Lots (4,143 sq ft
ave.)
• 15 acres (63%) Open
space
• Effective impervious
area approaching 0%
PRINCIPLES OF LID SITE DESIGN: Value of
Native Soils and Vegetation
1/26/15
Hydrologic modeling comparing a conventional development and the
flow reduction benefits from individual practices for a low impact
development design.
Detention storage
reduced (ft3)
Detention storage
required (ft3)
Conventional development
270,000
Low impact development
• reduce development envelope
• and use bioretention
• and use minimal excavation foundation
• and use 20’ wide permeable road
Total
‐149,019
‐40,061
‐7,432
‐29,988
‐226,500
43,500
PRINCIPLES OF LID SITE DESIGN: Value of
Native Soils and Vegetation
PRINCIPLES OF LID SITE DESIGN: Value of
Native Soils and Vegetation
BMP T5.30 Full Dispersion
• 65/10/0.
• Sliding dispersion scale.
PRINCIPLES OF LID SITE DESIGN: Urban
Development and Small Lots
Possible but challenging to conserve and protect native soils and vegetation
in dense development settings
Danielson Grove/Triad and Associates
It takes a village…and fines
to protect trees and soil.
• Contractor training
• Bonding/fines
• Signage
PRINCIPLES OF LID SITE DESIGN : Protecting
Native Trees and Soil
• Conventional street design
increases drainage network
and efficiency.
• Local street right of ways
can constitute over 25
percent of the typical urban
watershed.
• Streams with buffers
constitute about 10 percent
of this sample watershed.
PRINCIPLES OF LID SITE DESIGN: Road
Networks
PRINCIPLES OF LID SITE DESIGN: Road
Networks
• Home
• Planned Development
• Community
• Watershed
• County/City
• Region
PRINCIPLES OF LID SITE DESIGN: Scale of
Analysis
PRINCIPLES OF LID SITE DESIGN: Regional
Planning
Avoid open-space fragmentation
15,000 sq. ft. lots
5,000 sq. ft. lots
site planning and protection
PRINCIPLES OF LID SITE DESIGN: Regional
Planning
Project by project cluster
development
Regional cluster development
Project vs. regional clustering
PRINCIPLES OF LID SITE DESIGN: Regional
Planning
Project vs. regional clustering
Arterials
PRINCIPLES OF LID SITE DESIGN: Small
Contributing Areas
Q&A
AGENDA
introduction and regulations
345
LID site design process
site assessment and layout
site planning and infrastructure
exercises
trees
principles of LID site design
wrap up
1. Project baseline/charter
2. Develop basis of design
3. Develop team and engage
stakeholders
4. Site inventory and analysis
5. Site assessment and develop Site
Plan
LID SITE DESIGN PROCESS: Overview
• Project Scope
• Project Schedule
• Construction
• Plant Establishment
• Construction Budget
• Jurisdiction and Code Requirements
• Sustainability Goals defined
• Maintenance Capabilities
LID SITE DESIGN PROCESS: Project
Baseline/Charter
• Project Background
• Specification and drawing format
• Sustainability requirements
• Property restrictions and easements
• Permitting and point of compliance
• Site Civil
• Frontage and Right‐of‐Way requirements
• Civil grading criteria
• Utility criteria
• Landscape Design Criteria
• Existing tree preservation
• Buffers
LID SITE DESIGN PROCESS: Develop Basis of
Design
• Owner/Developer
• Public agency reviewers
• Land use Planners/Zoning
• Transportation
• Utility department
• Stormwater Management
• Other
• Architect
• Civil Engineer
• Surveyor
LID SITE DESIGN PROCESS: Develop Team and
Engage Stakeholders
• Landscape Architect
• Geotechnical Engineer
• Wetland/Biologist
• Arborist
• Outreach
• Community stakeholders
• Fire & Police Department
• Owner’s contractor
• Funding partners
• Maintenance staff
• Other?
Gather existing analysis, inventories, and historic information:
Soil surveys and analyses
Historic records of altering wetlands/ stream channels
Aerial photos
Maps and site reconnaissance to verify topography
Location of groundwater protection areas and/or well head
protection zones
Descriptions of local site geology
Site reconnaissance and characterization
Characterize hydrologic, geologic and biologic conditions
Used to inform overall design and location of infrastructure
Investigate steep slopes and landslide hazards near project site
LID SITE DESIGN PROCESS: Site Inventory
and Analysis
NPDES Permit Minimum Requirement #1
Preparation of Stormwater Site Plans:
Use site‐appropriate development
principles to retain native vegetation
and minimize impervious surfaces to
the extent feasible.
Local codes will change to incorporate
certain LID principles.
Prepare a Stormwater Site Plan for
local government review
LID SITE DESIGN PROCESS: Stormwater
Site Plan
Minimum Requirement #1 Preparation of Stormwater Site Plans
LID SITE DESIGN PROCESS: Stormwater
Site Plan
1. Analyze
Existing Site
Conditions
2. Preliminary
Site Layout
3. Off‐site
Analysis
4. Determine
applicable Min.
Requirements
5. Prepare
Permanent
Stormwater
Control Plan
6. Prepare
Construction
SWPPP
7. Complete
Plan
8. Check for
Compliance
1. Site Analysis: Collect and Analyze Information on Existing Conditions
(Volume 1, Section 3.1.1)
• Survey
• Soils Report
• Professional (on‐site sewage designer OK if only MR #1 ‐ #5)
• Surveys, test pits, borings
• Ksat field tests or grain size analysis
• Depth to restrictive layer – need winter data
• Lateral flow assessment (MR #1 ‐ #9)
• Vegetation survey of any protected areas
LID SITE DESIGN PROCESS: Stormwater
Site Plan
LID SITE DESIGN PROCESS: Stormwater
Site Plan
• Small Commercial: one small‐scale PIT
• Large Commercial: small‐scale PIT every 5,000 sq. ft.
• Residential: small‐scale PIT at each potential site
• Per 200 feet for long, narrow layout; e.g. road ROW
• Groundwater thru wet season – adequate clearance?
• Correction factor for native soils: CFv = 0.33 to 1
• WWHM guidance
• Legal Documentation
Site Procedures and Design Guidance for Bioretention/Rain Garden
(Volume 3, Section 3.4)
LID SITE DESIGN PROCESS: Stormwater
Site Plan
Stormwater – related Site Procedures and Design Guidance for
Permeable Pavement (Volume 3, Section 3.4)
• Sites where only MR 1 – 5 apply:
• Infiltration test per 5,000 sq. ft./wet season ground water
• Commercial sites where MR 1 – 9 apply:
• Small‐scale PIT per 5000 sq. ft.; at least 1 per site
• Residential sites where MR 1 – 9 apply
• Small‐scale PIT per 200 ft of road & every lot
• Criteria for reduction of test frequency
• Groundwater thru wet season
LID SITE DESIGN PROCESS: Stormwater
Site Plan
• Assignment of Infiltration Correction Factors
• Soil Suitability Confirmation
• Project…