Resilient Watersheds: Climate Adaptive Stormwater ...€¦ · 2018-11-02 · Excessive urban...

Resilient Watersheds: Climate Adaptive

Stormwater Management for Waters & Wildlife

Part Two:

Regenerative Stormwater Conveyance: Mill Creek Project Overview

***Thursday, October 11, 2018

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Cumberland River Compact Model Forest Policy Program 2

Logistics:

Participants are muted for audio quality

Use chat box for comments and sharing resources

Use Q&A panel for questions

Download slides and handouts from notes panel

Webinar recording will be shared

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Three-Part Short Course:

1. Adaptive Stormwater Strategies for Extreme Weather Resilience - Tues, Oct 2, 2018

2. Regenerative Stormwater Conveyance: Mill Creek Case Study - Thur, Oct 11, 2018

3. Getting Started with Local Adaptive Stormwater Management - Tues, Oct 16, 2018

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Resilient Watersheds: Climate Adaptive Stormwater Management

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Protect the health and enjoyment of the Cumberland River and its tributaries through education, collaboration, and action.

Build the capacity of communities to be climate resilient by sustaining water resources, productive forests, citizens’

wellbeing, and thriving economies.

Teach Restore Connect

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Gwen Griffith, DVM, MS

Model Forest Policy Program

& Cumberland River Compact

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Climate Solutions University (MFPP)

Adaptation planning director

Project manager

Climate adaptation

Watershed resilience

Adaptive stormwater management

Building Outside the Box (CRC)

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Steve Casey, PE, CPESC

Civil and Environmental Consultants, Inc.

Nashville, TN

Principal Engineer

Civil Engineer, Water Resources Focus

Stormwater Management & Erosion Control

Hydrologic Modeling / Basin Analysis

Floodplain Management

TN Erosion & Sediment Control Handbook

NPDES Compliance Services / MS4 Permits

Instructor, TDEC Level 2, Erosion Prevention and Sediment Control for Construction Sites

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Cumberland River Compact Model Forest Policy Program

Resilient Watersheds: Mill Creek Project

Project Collaborations: Williamson County Schools Nolensville High School University of Tennessee, Knoxville Civil and Environmental Consultants, Inc. Viking Products, Inc. Jones Company

Funding Partners:

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Topics:

Mill Creek Project Overview

Site Analysis & Stormwater Retrofits

Regenerative Stormwater Conveyance

Review Interactive Homework

Interactive Exercises Part 2

Session 2:

Regenerative Stormwater Conveyance: Mill Creek Case Study

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Increasing frequency of extreme weather impacting watersheds, wildlife, & water resources

Proactive measures to reduce and prepare for unavoidable impacts

Storms – Floods - Droughts – Wildfire

Changes will continue for decades

Why Resilient Watersheds?

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https://science2017.globalchange.gov

https://science2017.globalchange.gov/



Excessive urban stormwater runoff

Reduced groundwater recharge

Pollutants from lawns, parking lots, construction sites, chemicals, vehicles, sewer overflows, etc.

Streambank erosion

Stream modifications

More frequent, intense floods

More frequent, intense droughts

Impacts to Urban Streams from Built Infrastructure

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Warmer air and water temperatures

Heat stress and low dissolved oxygen

Frequent, intense rainfall & flood events

More extreme stormwater runoff volume

More water pollution and erosion

Reduced groundwater recharge

More severe drought events

More rain and less snow

Changes in seasonal timing for stream flow, plant, animal, and insect life cycles

Impacts to Urban Streams from Shifting Weather Extremes

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A Threat Multiplier

Photo: Jimmy Smith



The result of altered flow regimes, not just water quality:

Frequent flash flooding

Eroded, unstable water channel

Degraded water quality

Impaired aquatic habitat

Reduced biological diversity

Imbalance of aquatic species

Reduced base flow to stream

More intense drought events

Urban Stream Syndrome

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Mill Creek Watershed

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108 square miles, 69,000 acres

Rapid urbanization

Urban refugia for wildlife

Impairments: pathogens, dissolved oxygen, siltation, and nutrients

Frequent severe flooding

Federally endangered Nashville crayfish (Orconectes shoupi)

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Wide-scale use of multiple layers of watershed stewardship that restores a natural flow regime:

Land use planning and management

Low impact development practices

Stormwater policy, regulations, and program implementation

Green infrastructure and regenerative stormwater control that mimics natural hydrology

How to Cure the Urban Stream Syndrome?

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… …. climate adaptive stormwater management is a component of adaptive management to address trends in weather extremes of temperature and precipitation

… regenerative stormwater management restores natural hydrology to optimize watershed function and ecological health

Watershed Resilience:

What do we mean by adaptive or regenerative stormwater management?

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Mill Creek Resilience Project Goals:

Increase climate resilience of Mill Creek waters and wildlife, a priority urban stream

Demonstrate a suite of restoration and regenerative stormwater control measures that address impacts of weather extremes and development

Provide education at all levels from elementary, middle, and high school students, to training of professionals, elected officials, businesses, educators, and landowners

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Short Course Learning Objectives:

Increased awareness of impacts of extreme weather and development on aquatic habitat & water resources

Understand the methods and benefits of climate adaptive stormwater control measures

Catalyze replication of regenerative stormwater conveyances at the watershed scale necessary to protect stream health from development and extremes of temperature and precipitation

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Mill Creek Conservation Opportunity Area

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Endangered Nashville Crayfish (Orconectes shoupi)

Project Site

Nashville

Threats:

Stormwater runoff

Sedimentation (construction)

Stream modifications

Bioaccumulation of contaminants

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Mill Creek



Mill Creek Project Overview

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Nolensville High School Campus

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Mill Creek Headwaters

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Mill Creek

Nolensville High School Campus

Mill Creek Headwaters

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Bioretention Zone #1 – Parking Island

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Before

After



Bioretention Zone #2 – Lawn Drain

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Before


One Regenerative Stormwater Conveyance (RSC)

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Before

After



Green Way & 2 Foot Bridges

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Numerous sites for planting trees and vegetation in buffer zones

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PRESENTATION TITLE HERE 30

Project Co-Benefits Educational Programs

• Working with Williamson County Schools,

principals, teachers, facility managers, and

developers

• Classroom and outdoor programs

• River Talks – Public lectures

• Public site tours and signage

• Professional training workshop

• Virtual short course

• MS4 regulatory compliance

High School

Middle School

Elementary School

Co-Benefits


Questions?

Comments?

Observations?

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Civil and Environmental Consultants, Inc.

Nashville, TN

Stormwater Retrofits at Nolensville High

School

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Questions to explore opportunities for local implementation

Handout provided with questions and resources to investigate

Share your findings in the third and final webinar

Regenerative Stormwater Local Questions – Part 2

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What are the anticipated priority climate risks for your region?

What are your local weather trends now and future projections?

What are the exacerbating stressors for your community or jurisdiction? Population? Impervious cover?

Who are local resilience leaders and what is already being done to address your climate risks and non-climate stressors?

Regenerative Stormwater Local Exploration – Stage 1

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1. What are the priority climate risks identified for your region? List the top 3-5 issues. Are you feeling the impacts now? How? What non-climate stressors exacerbate these risks?

Fourth National Climate Assessment: Regional Summarieshttps://www.globalchange.gov/nca4

EPA State Summaries – (EPA archived website)https://archive.epa.gov/epa/climate-impacts/climate-change-impacts-state.html

Your State Climatologist

State or local climate adaptation plans or reports

Regenerative Stormwater Take Home Exercises

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https://www.globalchange.gov/nca4

https://archive.epa.gov/epa/climate-impacts/climate-change-impacts-state.html

Climate Change in Tennessee

Rising Air Temperatures - Average up 2 Fahrenheit since 1970 More evaporation and drier soil conditions between rainfall Droughts more severe and prolonged – 2007, 2012, 2016 Lower Water Levels – Impacts habitat, reduces shipping and TVA power generation

Rising Water Temperatures – Impacts aquatic life, lower oxygen, thermal stress, and algal blooms

Increased Flooding - Heavy rainfall more frequent and intense Chattanooga flood of 2003 / Nashville flood of 2010 Increases pollution and damages water quality

Agriculture – longer growing seasons, heat & drought reduce crop yields, stress livestock Forests – tree composition will change, increased damage from disease and insects Human Health – heat waves, air quality problems, food, water, and insect-borne disease

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TDOT Extreme Weather Vulnerability Study

Selected Risk Findings: Extreme Weather Floods and Landslides, Heat Waves and Drought Trend Analysis Upward Damage to InfrastructureChanging Construction Specifications



2. What are your county level weather trends and projections for temperature and precipitation changes through 2100?

Number of extreme heat days over 95 degrees F now? In 2050? In 2100?

Number of extreme rain events > 3 inches in 24 hrs. now? In 2050? In 2100?

NOAA Climate Explorer

https://toolkit.climate.gov/tools/climate-explorer

NOAA National Centers for Environmental Information / State Summarieshttps://statesummaries.ncics.org/ (2014)

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Regenerative Stormwater Take Home Exercises

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https://toolkit.climate.gov/tools/climate-explorer

https://statesummaries.ncics.org/

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https://crt-climate-explorer.nemac.org/

County Level Observations and Projections

***Temperature Precipitation

Heating/Cooling Growing Days

Williamson County, TN - Temperature

Annual # of days with maximum temp above 100˚F

< 20 days thru 2000 / 60-80 days by 2050

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Williamson County, TN - Precipitation

Annual # of days with rainfall > 3 inches

< 1 days thru 2000 / 2-4 days by 2050

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3. What are the non-climate stressors for your community or jurisdiction? Population trends? impervious cover?

U.S. Census population trends https://www.census.gov/

Impervious cover percentages and trendsUSGS National 100-meter land cover map https://nationalmap.gov/small_scale/mld/impe100.html

Regenerative Stormwater Local Exploring – Stage 1

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https://www.census.gov/

https://nationalmap.gov/small_scale/mld/impe100.html



Town of Nolensville, TN - 37% growth since 2010

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4. Who are local resilience leaders? What is already being done to address your climate risks and non-climate stressors?

Local government agencies or programs

Nonprofit environmental, health, or social justice organizations

Business leaders


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TN State Wildlife Action Plan (SWAP)

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TN Precipitation & Temperature Forecasts

Average Total Annual Rainfall Increase from 50.1 inches to 53.6 inches

Extreme Heat Baseline1961-2000

Mid-Century2046-2065

Avg. Summer Temp 88.5 F 94.8 F

Highest 7-Day Avg. 94.9 F 101.9 F

# Days Above 95 F (Annual)

10 days 59 days

# Days Above 100 F (Annual)

1 day 16 days

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Take a drainage detective walk around your building and document where the stormwater runoff goes. Any problems? Improvements?

Ask a civil site engineer the pros and cons of an inverted parking lot island for bioretention.

Identify a small stream with signs of urban stream syndrome, delineate the drainage basin, and consider restoration strategies.

What do you know about the NPDES stormwater permit for your community? Does the stormwater committee consider climate projections in permit decisions?

Consult NOAA Atlas 14 for the rain depth of your local 100 year / 24 hour design storm.


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Drainage basin delineation to the Mill Creek

project site 3.22 sq. mi.

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Three-Part Short Course:

1. Adaptive Stormwater Strategies for Extreme Weather Resilience - Tues, Oct 2, 2018

2. Regenerative Stormwater Conveyance: Mill Creek Case Study - Thur, Oct 11, 2018

3. Getting Started with Local Adaptive Stormwater Management - Tues, Oct 16, 2018

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Upcoming Speakers

Catherine Price

Education Program Manager

Cumberland River Compact50

Jon Hathaway, PhD, PE

Civil & Environmental Engineering

University of TN, Knoxville

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Webinar #3: October 16, 2018

Getting Started with Local Adaptive Stormwater Management

Priorities, processes, and partners

Watershed hydrology - scaling up to watershed scale

Co-benefits of green infrastructure approach

Potential funding sources

Interactive exercises wrap up 51


Questions?

Comments?

Observations?

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Gwen Griffith, DVM, MS [email protected]

Jon Hathaway, PhD, PE

[email protected] and http://hathaway.utk.edu/


[email protected]

Catherine Price,

[email protected]


mailto:[email protected]


http://hathaway.utk.edu/



Resilient Watersheds: Climate Adaptive Stormwater ...€¦ · 2018-11-02 · Excessive urban...

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