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1/18/2017
1
RAINSCAPES ENVIRONMENTAL SITE DESIGN WORKSHOP
MONTGOMERY COUNTY, MD DEPARTMENT OF ENVIRONMENTAL PROTECTION WATERSHED MANAGEMENT DIVISION RAINSCAPES PROGRAM
JANUARY 18, 2017
HOMER S. GUDELSKY INSTITUTE FOR TECHNICAL EDUCATIONROCKVILLE, MD
RAINSCAPES.ORG
AgendaAgenda
Core Concepts of Environmental Site Design (ESD)
Stormwater, our Watershed and the MS4 Permit
Site Assessments for ESD
Rain Gardens and Conservation Landscapes: Design, Construction and Examples
Rebate Program
Questions
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CORE CONCEPTS OF ESD
Small scale vegetative practices integrated throughout the site, as close to the source as possible, to mimic pre-construction and natural hydrology
RAINSCAPES = LID = ESD = GREEN INFRASTRUCTURE
Old Approach to StormwaterManagement
Catch water at the bottom of the hill, concentrates water flow and pollution
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1. Healthy Soils and Native Plant Benefits • Organic matter increases
infiltration rate• Native plant roots open
up soil drainage structure
2. Decentralized Small Scale Design Approach• Slow it down, spread it
out and soak it in
3. Treatment Train Approach• Using multiple practices
together to manage stormwater
Core Concepts of Environmental Site Design
Infiltration!Soil is Mother Nature’s Filter
•The minerals in soil act as a filter.
•Soil is full of carbon from decaying plantsand animals. Carbon is a great filter.
•Healthy soil is full of micro organismsthat can help break down pollutantssuch as pesticides and petro-chems.
• Healthy de-compacted soilsinfiltrate stormwater faster
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Value of Using Native Plants
•Deeper roots – absorb more water and aids in soil de-compaction
•Use no fertilizer
•Use little or no pesticides
•Do not require watering after establishment
Why we care about roots!
Root systems play a large part in rainwater infiltration.
They store more water and create avenues for water to drain deeply into the soil.
(Courtesy of Mid-America Regional Council)
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Carex muskingumensisLobelia cardinalis
Provide Wildlife Habitat
Birds
Butterflies
Bees
Aesclepias tuberosaButterfly Weed
Cephalanthus occidentalisButton Bush
Ilex verticillataWinterberry
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Stormwater, Our Watershed and MS4
StormwaterRunoff
Rainwater that flows off impervious surfaces such as rooftops, driveways, roads and sidewalks picks up pollutants on the way, including chemicals from our lawns.
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What is in stormwater runoff?
Volume and velocity impacts!
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We cannot do this anymore….because it is damaging our watershed
An area of land that drains its stormwater into a body of water.
What is a watershed?
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Example Subcatchments
(aka drainage areas)
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19
There are over 1,500 miles of streams in Montgomery
County
Montgomery County
This is the Chesapeake Bay watershed
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1972
Clean Water Act
NPDES (National Pollutant Discharge Elimination System)
Permit Program
1987
MS4 (Municipal Separate Storm Sewer System) Permit
Program
Expanded Point Source discharge pollutant measures to require municipalities to get permits for stormwater runoff
discharge
2007
Maryland Stormwater Act
effective May 2010
Maryland StormwaterDesign Manual included a
new Chapter 5
requires environmental site design to the maximum extent
practicable
“ESD to the MEP”
Montgomery County
NPDES MS4
Permit =
Stormwater Discharge Permit
2010‐2015
Federal CountyState
What are we facing?
• Rain events have increased in intensity and may be changing drainage patterns
• Communities and homeowners confronted with large volumes of water from lot to lot drainage
What are you facing?
….Assessing a site for ESD
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Assessing Sites for ESD
Single FamilyMulti Family
Institutional/Pools
Some initial things to consider…
Identify Any Legal Requirements
• Home Owner Association Rules
• Local Ordinances
• Right-of-Way and Easement Locations
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Site Assessment Forms
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Step 1 continued
• What are you trying to accomplish? = Client Interview
• Solving an existing flooding / erosion problem = Solution can be involved ($$$) to handle the water that is coming through
• Preventing pollution = Solution can be more straightforward
…or combine both
• Where is the water coming from?
• Property owner’s downspouts,
• uphill neighbor’s roof, • or both?
• How much water? How fast?
Steps to a RainScapes Site AssessmentStep 2
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Single Family Home
Are you looking at somethinglike this?
Or something like this? Homeowner roof and lot to lot drainage
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Steps to a RainScapes Site AssessmentStep 3Identify impervious surfaces and note direction of flow
Single Family Home
LOOK FOR SINGLE SOURCE OPPORTUNITIES
Multi-Family
Do the downspouts drain on gradeor are they piped underground?
Where do they daylight?
Are they functioning/clogged?
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LOOK FOR MULTI-SOURCE OPPORTUNITIES
Multi-Family
Project determination
• Is the water draining to open lawn areas or heavily treed areas?
• What is the slope of the property?
Open lawn space and more level sites = Rain Gardens (no utilities and must pass a perc test)
Heavily treed lots and steeper grades = Conservation Landscape
Lots of pavement = Permeable pavers
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Residential Rain Garden
Water flow
Possible Rain Garden
- Change landscape practice: have plantingsextend to bed edge instead of trench, usegroundcover such as sedum ternatum, heuchera, tiarella.
Must pass a perc test- Call Miss Utility- No tree roots impacted
RAIN GARDEN = open lawn areas
Must pass a perc test
Call Miss Utility
No tree roots impacted
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Permeable paver retrofit project.Rebate requires certified contractorthrough Interlocking Concrete Paver Institute (ICPI) specializing in PICP.
(Permeable interlocking concrete pavers)
Rain garden project
Direct downspout water runoff to rain garden. Size for the amount of roof or other impervious surface runoff the rain garden is handling.
Possible Rain Garden
Permeable Pavers
Permeable Pavers
PossiblePermeable Pavers
This house is at thebottom of the hill
A LOT OF WATER COMING IN AND NOT MUCH SPACE TO DEAL WITH IT
Rain Garden Rules: Fence lines and foundations 10’ away
Except…
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Conservation Landscapes for steep slopes and sites with
slopes and trees need Check Dams
Series of swooping stone check dams with small boulders and cobble slow and spread water flow into new plantings betweenthe check dams
Lots of paved surface & not much green space = Permeable Paver Retrofit
MUST BE PICP CERTIFIED THROUGH ICPI
(interlocking concrete paver institute)
Creating “Green Islands” in your parking lot
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TREATMENT TRAIN = COMBINING 2 OR MORE ESD PRACTICES ON ONE SITE
Church Property HOA Property
Commercial / Institutional Scale Site Assessment
Check dams
PUTTING IT ALLTOGETHER
Residential Treatment Train….
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SHEET FLOW OFF PARKING AREA
TREATMENT TRAINS
INSTITUTIONAL/POOLS=
LARGE PARKING LOTS
Overflow directthrough garden
AFTER THE SITE ASSESSMENT…
WHAT NEXT?
perhaps you want to do a rain garden…
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First do a perc test…butCall before you dig!
Miss Utility811
national call before you dig line
http://www.call811.com/
PERC TEST STEP 1:
To find out how fast your soil drains, do a perc test.
Break up the soil with a digging bar.
STEP 2:
Remove the soil with a post hole digger.
Use a trash bag to contain the soil.
STEP 3:
Dig a 2 foot deep by 1 foot wide hole OR
Dig as deep as you will excavate.
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STEP 4:
Fill hole to the top with water.
Record the time when hole is filled.
STEP 5:
Cover the hole for safety purposes.
STEP 6:
Check the hole and record how long it took to empty.If hole drained in less than 36 hours, repeat steps 1-5 in same hole.
•Site did not pass a perc test•Underground utilities running through the site•No place to overflow•Too steep
DESIGN A CONSERVATION LANDSCAPE•Minimum of 250 sq. ft./ 350 sq. ft. commercial, multifamily
•Replacing existing turf, invasive plants or solving an erosion problem
•Must have an impervious surface draining to the site
•75% natives, cultivars OK
Perc test passed!!! OK FOR DESIGNING A RAIN GARDEN
Perc test failed!!!
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RAIN GARDENS AND CONSERVATION LANDSCAPE DESIGN AND CONSTRUCTION
Sizing your Rain Garden and Conservation Landscape:
Measure your roof /drive area
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Sizing Chart Calibrated for Montgomery County, MD
• Assumes 6” of ponding, SF is media footprint
• ‘1 foot planting bed’ refers to planting media depth
• The numbers in the colored area indicate inches of rain captured/ treated/ stored in a 24 hour time period
• Double the media footprint when using this chart to size you Conservation Landscape
• Need to treat at least 1.2 inches of rain
• We would request at least 2 given our recent
• rain events
Ponding vs. Soil Media Footprint
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INSTALLING RAIN GARDENS
Soil Replacementvs.
Soil Amended
THE WATERFORD EXPERIMENT
Soil ReplacementRain Garden
VSSoil Amended Rain Garden
175 sf media foot print, IA=780 sf12” planting depth, 3” mulch layer, 6” ponding
290 sq ft media foot print, IA= 2580 sf12” planting depth, 3” mulch layer, 6” ponding
Both sites passed a perc test, drained within 24 hours/2 fills
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Hauled 2 truck loads of soil away4 hours to get ready for planting
Excavated 21”Hauled soil away
21” excavation=
12” planting depth 3”mulch layer 6”ponding depth
SOIL REPLACEMENT RAIN GARDEN
SOIL AMENDED RAIN GARDEN
No soil hauled away,2 hours to get ready for planting
9” excavation=
3” mulch layer 6”ponding depth
12” planting depthTilled in 2” compost
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THE WATERFORD EXPERIMENTFIRST RAIN EVENT AFTER INSTALLATION
SOIL REPLACEMENT COMPOST AMENDEDVS
AFTER ONE YEARCompost amended garden
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Soil replacement garden
AFTER ONE YEAR
Rain Gardens
xcavate 11”6” PONDING3” MULCH
2” COMPOST
12” DEEP COMPOST AMENDED
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Drain pipe
Swale
Splash blocks
Downspout
Berm
Gutters
Rain Gardens
Bottom of pipe should be above the max ponding depth!!!!
You may need to move the down spout water to the rain garden.
Must be 75% native plants, cultivars OK!
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Using Trench Drains, Dry Stream Beds and Linear Dry Wells to Direct the Water Flow
Must stabilize berm slopes, this is a little steep
With lot to lot drainage,should oversize your rain garden
Sheet flow
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Area is too steep for a rain garden,
Best practice is
CONSERVATION LANDSCAPE WITH
CHECK DAMS
Planting in swales =be careful, how much water is coming through and how fast?
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Check Dams-How big, how many and how far apart?
Slope/Velocity, VolumeAsthetics
RAIN GARDEN PLANTER
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Rain Garden Planter
Before After
Before After
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Plant by Moisture Type in Rain Gardens:Right Plant in the Right Place
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MATURE
SIZE
MATTERS
PLANT
PLANTING FOR EASY MAINTENANCE!
• Fewer varieties in larger groupings
• Mature size matters
• Clump grower vs “Naturalizer”
• Start with the appropriate container size for the project
Have a hand watering schedule for 6 weeks3x a week for 2 weeks2x a week for 2 weeks1x a week for 2 weeks
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Important to space ground cover layer plants to fill in
within a year without overgrowing the space
Do native cultivars have the same benefits for pollinators as straight species? It depends
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Graphics from Designing with Natives by JRogers
Runoff control and so much more
Graphic from Designing with Natives by JRogers
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Other benefits to the environment
Plant selections based on plant communities
Try to create or emulate a specific habitat, like woods, wetland, or meadow
Physical/ aesthetic layout based on client’s style preferences
Upland meadow species
Wet meadow/ woods edge species
Wet meadow/ stream edge species
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EXAMPLES
Conservation Landscape in a swale
Water flow
Rain Garden overflow to Conservation Landscape
Rain Garden
Berm
Conservation Landscape
Water flow
(40)
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Water Flow
Treatment Train =
stone check dams, planted dry stream to 2 tier Rain Garden
Eastern Red Cedar
Blue Eyed Grass
Penstemon Husker Red
Dwarf Crested Iris
River Birch
False Blue Indigo
Aster ‘Alert
Creeping Phlox
Dry Well
In tune with residential aestheti
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Front yard conversion torain garden and conservation landscape
Congregational site
Before After
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Treatment trainCaptures drainage from 3 lots
Very compacted turf
Conservation landscape and dry wells plus underdrainedrain garden above
Front Yard as Front Porch: Transformation
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Excessive road drainage = large dry well with CL
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REBATE PROGRAM
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RainScapes Techniques in Action
RainScapes RewardsIncentive Program
Rebates for single family residences: $2,500 per property with lifetime project caps
Rebates for multi-family/commercial / institutional:$10,000 per propertywith lifetime project caps
All County property owners outside of municipalities Rockville, Gaithersburg and Takoma Park are eligible for rebates
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Rewards Rebate Program: Rain Gardens
• Residential: $1,200 per garden or a square foot amount based on soil depth , which ever is greater
• Commercial : $2,500 per garden or a square foot amount based on soil depth, which ever is greater
Sized for 1.2” rainfall volume minimum
75% plants must be native
Site must pass a perc test
Rewards Rebate Program: Conservation Landscaping
• $2.00-$3.00 per square foot/microberms
• Minimum 250 square foot conversion of turf area or invasive species.
• Impervious surface must drain into site
• 75% Native Plants
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Rewards Rebate Program:
Tree Canopy• Will eventually shade or cover
impervious surface-reduces heat pollution
• 10’-15’ away from permanent buildings
• Tree is on our published canopy trees list
• Planted between September 15 and April 30th
• Root flare is exposed• $200.00/tree
Rewards Rebate Program:
Permeable Pavers• Installed by a certified ICPI
contractor with an additional certification in PICP
• Replaces existing impervious surface
• A downspout filter must be used if the downspout is connecting into the pavement.
• If downspout is connected to the system add $4.00/sq ft for impervious surface that downspout is handling
• 1,200 or $4.00 a square foot IA treated.
• Whichever $ amount is • greater.
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Rewards Rebate Program:
Pavement Removal• $4 per square foot for
conversion to a conservation landscape
• $2 per square foot for conversion to turf.
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Rewards Rebate Program:
Green Roofs• $10/ SF
• Minimum 250 square feet
• Must be on an existing roof
Rewards Rebate Program:
Rain Barrels and Cisterns• $1.00 per gallon
• $250 maximum per property for rain barrels; $500 maximum for cisterns
• must capture 200 gallons min. for rain barrels, 250 gallons min. for cisterns
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Rewards Rebate Program:
Dry Wells• $1.00 per gallon
• $600 per property
• May be linear drywell OR conventional dry well
• DIY or contractor installed
Easy Application process….• Fill out on line application (15 minutes!!)
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• We will come out for a preliminary site inspection before you start work meet with you and your client
• Locate/verify possible project sites
• You will need to contact miss utility, any required perk test results and submit a plan for our review and approval to start
• You will need to be PICP certified through the ICPI if installing permeable Pavers
EASY APPLICATION PROCESS
• Contact us when you are finished for final inspection
• Submit copies of receipts and signed POA (property owner agreement)
• Rebate check in 4-6 weeks
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Check out our website for more info on designs
www.rainscapes.org
Water Quality Protection Charge (WQPC)Credit Program
Once you install a RainScapes project you are eligible to applyfor WQPC credit toreduce this annualcharge (included with your property taxes)
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NGICP
LEED
SITES
CBLP CERTIFICATION
MONTGOMERY COLLEGE
www.rainscapes.org
Adam Ohl
RainScapes Principal Administrative Aide
240‐777‐7702
RAINSCAPES PROGRAM CONTACT INFO:
RainScapes Team
Carla Ellern ,RLA, ASLA, LEED AP BD+CRainScapes [email protected] 240‐777‐7756
Donna Evans, LEED GARainScapes [email protected]‐777‐7798
Pamela RoweRainScapes [email protected]‐777‐7714
Ann English, RLA, ASLA, LEED AP BD+CRainScapes Program [email protected] 240‐777‐7759