Bioretention & Bioswales - Rutgers Cooperative Extension ...water.rutgers.edu/Recent_Presentations/141215_BioretentionBioswal… · CALL BEFORE YOU DIG •Free markout of underground

Jessica Brownwww.water.rutgers.edu

Raritan Township Presentation

December 15, 2014

Bioretention & Bioswales

Rutgers Cooperative

Extension

Water Resources

Program

http://www.water.rutgers.edu/

Water Resources Program

Agenda

11:00 Welcome and Introductions

11:05 Stormwater Management & Green Infrastructure

11:15 Bioretention and Bioswale Design

11:20 Bioretention and Bioswale Application (retrofits, construction)

11:35 Maintenance

11:55 Introduction to projects in the Neshanic Watershed

[Kyle Gourley, Project Manager]

12:00 Questions, Certificates, and Adjourn


Rutgers Cooperative Extension

Rutgers Cooperative Extension (RCE) helps the

diverse population of New Jersey adapt to a rapidly

changing society and improves their lives through an

educational process that uses science-based

knowledge.


The Rutgers Cooperative Extension (RCE) Water

Resources Program was created to help provided

solutions to New Jersey’s water resources problems.

It is a multi-disciplinary program that integrates

teaching, research, and extension and develops strong

partnerships.


Water Resources ProgramOur Mission is to

identify and

address

community water

resources issues

using sustainable

and practical

science-based

solutions.


• Chris Obropta, Ph.D., P.E.

• Jeremiah Bergstrom, LLA, ASLA

• Jessica Brown, E.I.T.

• Lisa Galloway Evrard

• Sara Mellor

• Kyle Gourley, E.I.T.

• Rosana Da Silva

• Chris Perez

• Michelle Hartmann

• Tyler Wibbelt


What is Stormwater?Stormwater is

the water from

rain or melting

snows that can

become

“runoff,”

flowing over the

ground surface

and returning to

lakes and

streams.


More

development

More impervious

surfaces

More stormwater runoff

10%20% 30% 55%

The Impact of Development on

Stormwater Runoff


The Urban Hydrologic Cycle


POINT SOURCE POLLUTIONNONPOINT SOURCE

POLLUTION

Environmental Health Perspective, National Institute of Health

Water Pollution Sources


Nonpoint Source Pollution (NPS)

• Associated with

stormwater runoff

• Runoff collects pollutants

on its way to a sewer

system or water body

• It cannot be traced to a

direct discharge point

such as a wastewater

treatment facility


Examples of NPS• Oil and grease from cars

• Fertilizers

• Animal waste

• Grass clippings

• Septic systems

• Sewage leaks

• Household cleaning products

• Litter

• Agriculture

• Sediment


TO MINIMIZE IMPACT OF

STORMWATER RUNOFF, YOU MUST

CONTROL RUNOFF FROM

IMPERVIOUS SURFACES


We must deal with impacts from impervious cover

Are there impervious surfaces that you can eliminate?

Are there impervious surfaces that you can harvest rainwater

for reuse?

If we can't eliminate it, can we reduce it?

If we can't eliminate or reduce it, can we disconnect it?

Are there conveyance systems that can

be converted to bioswales?


Green Infrastructure is ...

…an approach to stormwater management

that is cost-effective, sustainable, and

environmentally friendly.

Green Infrastructure projects:

• capture,

• filter,

• absorb, and

• reuse

stormwater to maintain or mimic natural

systems and treat runoff as a resource.


Lots of Options for Green Infrastructure SCMs

• Bioretention

• Cisterns

• Curbless

Parking Lots

Islands

• Downspout

Disconnect

• Grassed

Swales

• Green Roofs

• Wet Ponds

• Infiltration

Trench

• Narrow Roads

• Permeable

Pavement

• Rain Barrels

• Rain Garden

• Sand Filter

• Tree Planting

• Buffers

• Wetlands

• Dry Detention

http://cfpub.epa.gov/npdes

/stormwater/menuofbmps


Video


Bioretention Goals1. Restore/“mimic” predevelopment site hydrology

– Infiltration

– Evapotranspiration

2. Improve water quality

– Sedimentation, filtration, & plant uptake

– Microbial Activity

3. Add aesthetic value

– Plant selection

Photo: NCSU BAE Stormwater


What Does Research Tell Us?

SOURCE: The University of New Hampshire Stormwater Center, December 2011

To

tal S

usp

en

de

d S

olid

s

Tota

l P

hosphoru

s


Dis

solv

ed I

norg

anic

Nitro

gen


The System

Bioretention Cell

1 2

3

Media

Gravel Layer

Drainage

Bowl

Underdrain

Mulch Layer


Swales

Photo: NCSU BAE Stormwater, Eve Brantley


Swale Function

Pollutant Removal & Small Volume Control

Typically doesn’t provide

active volume capture or

peak flow attenuation

Passive volume control -

depressional areas, check dams,

pervious surface


Swale Characteristics

• SHWT should be >1’ below footprint

• Steep slopes not recommended, high velocities - <5%

• 0.5ft of freeboard recommended

• Mowing Maintenance or Landscaped areas

• Overflow


Bioretention

Bioretention Function


Bioretention Media

• Specialized

• 85-88% Sand, 8-12% fines, 3-5% organics

– Washed, Medium Sand (USGA greens mix not necessary)

– Fines – Clay and/or Silt

• 8% - 2 in/hr. infiltration rate

• 12% - 1 in/hr. infiltration rate (nitrogen removal)

– Organics – pine bark has been successful

• Purchase or Mix Yourself

– Pre-mixed is a more thoroughly mixed and has better

performance

– Ask before you buy


Gravel Depth and

Media Layers

• Media (@ least 1’)

• 4” Washed Sand

• 2” Choking Stone

• 6” Washed #57 Stone

Media

Washed Sand

Washed #57 Stone

>2 ft

Water Table

Choking Stone

Photo: NEMO (2010)

Water Resources ProgramMedia Depth

Depends on two components:

1. Target Pollutant

2. VegetationNutrients

3 ft

Metals and Oils

1ft

Pathogens

2ft

Temperature

4ft

Photo : Center for Watershed Protection (Pathogens), http://www.pavements4life.com/QDs/Images/Environment/1/6.jpg (Temperature)

Vegetation

Photo : http://www.ocoee.org/Departments/PU/images/sod.jpg (sod), http://www.lilylandscapes.com/Perennials/perennial_garden.gif (perennial), freefoto.com (tree),

> 2ft

> 3ft

http://www.pavements4life.com/QDs/Images/Environment/1/6.jpg

http://www.ocoee.org/Departments/PU/images/sod.jpg

http://www.lilylandscapes.com/Perennials/perennial_garden.gif


Underdrains

• Perforated PVC pipe

• 6” – centers recommended (perforations)

• Should be placed in permeable “sox”

Photo: Rob Brown, NCSU BAE


Internal Water Storage (IWS) Bioretention• Requires a 90-degree PVC upturned elbow, at least 12” below bowl

surface

• Forces elevated outlet

• Promotes exfiltration and ET

• Significant volume reductions

• Allows for denitrification

Photo: NCSU BAE Stormwater, Hunt et al., Rob Brown, PhD.


CALL BEFORE YOU DIG

• Free markout of underground gas, water, sewer, cable, telephone, and electric utility lines

• Call at least 3 full working days, but not more than 10 days, prior to planned installation date

• Do not place rain garden within 5’ horizontally and 1’ vertically from any utilities


Construction Tips

• Complete Survey and Stakeout and have

materials on-site before beginning construction

• Excavate in dry soil conditions (if possible)

– 1 week of dry, sunny, warm weather

• Don’t let it rain on exposed cut

– Could cause surface sealing

• Stabilize drainage area prior to adding media

– Could cause sedimentation and clogging

Maintenance


MAINTENANCE MEASURES

Monthly TASKS:

1. Watering

2. Weeding

3. Inspecting *

ANNUAL TASKS:

1. Mulching

2. Pruning

3. Re-planting

4. Removing sediment

5. Soil Testing

6. Harvesting Plants

7. Replacing materials

(stone, landscape fabric)


Preventative Maintenance

• Infiltration is most important

– need to avoid soil compaction

during construction

• Remember soils should have

adequate infiltration rates

(well- drained)

• Inspect sod or plants before

planting

• Conduct a soil test (especially

when laying sod) to determine

soil fertility


Swales – Preventative Maintenance

• Site Selection

– Seasonally high water

table should be 2’

below the bottom of the

system

– Swales should not carry

constant flows or flows

during dry weather,

bioretention shouldn’t

stay wet past 48 hours


• Construct and vegetate swales prior to surrounding

area grading and paving

• Paving areas surrounding the swale will result in high

velocity runoff volumes causing plant mortality

during plant establishment

– May depend on time of year

– Summer not a great time to install plants


Plant Establishment

• Irrigation is needed 2-3

times a week for up to 2

months

– During EXTREME

DROUGHT

• More often in summer

months and during a

drought

• Fall best time to plant

perennials


June 2010 June 2011


• Avoid using high velocity

volumes when watering

• Need to erosion resistant

matting if seeding the swale

• Sod should be kept moist for

first 2-3 weeks

• Every other day – 4”– May need to calibrate irrigation system to

determine time needed

• Biggest mistake is that

people water too often for

short periods of time


Swales – Erosion Control

• High velocity runoff volumes will cause excessive erosion

• Repair ruts or holes resulting from gully formation

• Re-seed, sod, replace plants, and/or use erosion control

matting to cover bare areas

• Want run off to sheet flow into the system, if possible


Mulch Layer

• Triple or double

shredded

• Aged a minimum of 6

months, 1 yr is better

• Should be 3” deep at all

times

• Keep mulch 6” from

tree and shrub trunks

• Holds in moisture and

can cause root rot if

kept too deep

• Prevents substrate

compaction

• Prevents weeds

• Traps sediment =

pretreatment to prevent

clogging

• Metals accumulate in

the top 1 to 2”

Triple Shredded Mulch


Turf Maintenance

• Mowing

– But grass should never be cut

below design depth

– Rule of thumb is no lower than

5”

– Should never remove more than

1/3 of the leaf at a time

• Remove clippings to avoid clogging

• Re-plant swale as needed for

dense growth


Pruning perennials and ornamental grasses

• Herbaceous – die back in winter

• Leave seed heads or cut back

• Can deadhead or remove spent blooms and will encourage

more flowering

• Native grasses – cut down to a few inches when dormant


Sediment and Trash Removal

• Remove sediment or debris

that has accumulated in or

around inlet and outlet

structures (Annually)

– Avoid transport of re-

suspended sediments during

large storms – this can

choke out vegetation

– Also prevents sediment

buildup that causes

damming or sandbars that

may inhibit flow patterns

• Inspect for source of

sedimentation


Watershed Protection and Restoration

Plan for the Neshanic Watershed

Proposed Designs:

• 2 Roadside Ditch Retrofits

• 2 Detention Basin Retrofits

• 16 Residential Rain Gardens

• 5 Commercial/Business Rain Gardens

2014/2015 Outlook:

• Rain Garden at Liberty Village Outlets

• Roadside Ditch Retrofit on Kuhl Road

• Two Rain Gardens at East Amwell

School

• Rain Garden/Swale at Shoprite of

Flemington

• Seven Residential Rain Gardens

(mostly in Flemington Borough)

• Continue searching for more project

locations

• North Jersey Resource Conservation and

Development was awarded grant by NJDEP -

Rutgers is assisting with design work

• Neshanic Watershed is a 31 square mile area

of mixed land use within the Raritan River

Basin

• Includes Flemington Borough, Raritan

Township, Delaware Township, and East

Amwell Township

• Many streams are impaired based on New

Jersey State standards for surface water

quality in the parameters of phosphorus, total

suspended solids, copper and aquatic life

• Implementing green infrastructure can

alleviate these impairments


Hamilton High School West Video

Rutgers Cooperative Extension


www.water.rutgers.edu

Jessica T. R. Brown, EI

[email protected]

Kyle Gourley, EI

[email protected]

http://www.water.rutgers.edu/

mailto:[email protected]

mailto:[email protected]

Documents

Bioretention & Bioswales - Rutgers Cooperative Extension ...water.rutgers.edu/Recent_Presentations/141215_BioretentionBioswal… · CALL BEFORE YOU DIG •Free markout of underground