1. September
2007
Reducing Stormwater Impacts in Heavily
Developed Areas; Winooski Rain Garden Project
Winooski Rain Garden Project
The Winooski Rain Garden project Project Preparation
was developed through a partnership between
UVM Extension Lake Champlain Sea Grant A flier was sent to all Winooski residents in
program’s NEMO program and the city of April as part of the town’s water bill mailing
Winooski. A study of the Morehouse Brook advertising the rain garden project. The pro-
found it to be severely impaired by stormwa- ject was also advertised in an article written
ter inputs just below Mallets Bay Avenue. about the project in the Burlington Free
Winooski, a historic city that is heavily devel- Press’s local section and through a live call in
oped, has little area to build traditional engi- program on the local cable access channel.
neered stormwater facilities. In the process of After receiving many emails and calls about
looking for an alternative way to reduce the the project a kick off meeting was held in late
May for interested residents. Site visits to North Street Rain Gardens
stormwater inputs to the Morehouse Brook,
potential garden locations were conducted by North Street rain gardens have about a
the rain garden project was developed to dem-
onstrate to residence and business owners the Emma Melvin. At the same time locations for 134,549 square feet watershed draining
low cost and low maintenance practice to the public gardens were reviewed by Emma into them. Twenty four percent of this
manage their stormwater runoff. Melvin and Erik Bailey.
area is covered by impervious surfaces
Rain gardens originate from the As part of the education component including houses, roads and driveways.
stormwater practice called bio-infiltration or of the project, in June, workshops were held
Not all of these impervious surfaces are
bio-retention. This practice mimics an upland on the function, design and installation of rain
gardens. These workshops were open to the asphalt or concrete, some are dirt and
forest’s natural functions of interception, infil-
public. All garden recipients were required to gravel drives.
tration, chemical transformation and ground
water recharge. Rain gardens have a two fold attend a workshop. Master gardeners inter-
These rain gardens were designed slightly
benefit; reducing stormwater flows and pro- ested in the project were also encouraged to
attend. As part of the workshop, the partici- oversized to compensate for the com-
ducing clean water. This project showed the
pants installed a rain garden at the Winooski pacted urban soils and somewhat larger
versatility of rain gardens as a small residen-
tial garden treating roof runoff, to a large pub- Wastewater Treatment Plant. Twenty three storms volumes (over one inch).
lic garden treating road runoff, to a small park people attended the two workshops held, and
eighteen people attend the project kick-off These rain gardens were functioning early
garden treating sediment laden stormwater
from a ball field, to the affects of a small gar- meeting. in April and infiltrated the spring snow
den on parking lot runoff. melt. They also captured water and sedi-
ment released during a water main break
The project was funded by the Ver-
mont Department of Environmental Conser- on North Street above the gardens.
vation 319 Non-point Source Pollution Pre- If the only surfaces within the watershed
vention Grant in June of 2006. Other partners
in this project include Winooski Environ- draining into the rain gardens were the
mental Leadership Board, University of Ver- impervious surfaces (~32,292 ft2) with a
mont Master Gardeners Program and Ver- precipitation of approximately 32.6 inches
mont Youth Conservation Corps. (storms less than 1 inch) during the time
period the rain gardens were functioning,
these gardens have treated 1,051,750 cubic
feet of stormwater, not to mention all the
sediment captured in the gardens.
2. Fence show aired early October.
Each of the larger gardens at
Landry Park was installed in a day. Each
was installed with a gravel entrance to dissi-
pate some of the erosive energy of the
stormwater as it enters the garden. An as-
phalt speed bump was also installed below
the curb cuts on the garden located along
North Street. These speed bumps were in-
Winooski Rain Garden Project stalled to help direct the stormwater in the
gardens. The gravel entrances were de-
signed to also allow for some water storage
and sedimentation for any thing being car-
Installation The next garden was installed on ried in the stormwater. Many of the plants
August 5, 2006 at Karen McCreas’ property used in these gardens were donated by mas-
Garden installation started on July on 103 North Street Winooski. This garden ter gardeners and others.
29 at Jim and Carole Foster’s property, 57 treated approximately the same size roof but
Cedar Street, Winooski. Ten master garden- Two rototillers, one loaned from
the rain water was directed to the garden by
ers volunteered for this garden installation. the Winooski Parks Department and one
a sloped drip line armored with cobble. This
The installation started with a short explana- rented from Essex Equipment were used to
garden was also installed by master gardener
tion of a rain garden, the design and steps of un-compact soils in all the of the gardens.
volunteers. Due to the high use and the common nature
the installation. This garden treated approxi-
mately 500 square feet of the Foster’s roof. of urban soils, they were of poor quality and
highly compacted. Replacement soils were
The garden dimensions were purchased from Intervale Compost. These
marked off with wooden pegs and string soils were used in the upper garden located
prior to the installation. The master garden- along North Street.
ers started by digging a one and a half foot
deep kidney shaped bowl with gently slop- The next garden installed was for
ing sides. The excess soils were used in cre- the Michael Dabb's’ property at 217 Mallets
ating a small berm on outside curve of the Bay Avenue. It was a unique garden given
planting bed. After the digging was fin- that it crossed underneath the front fence and
ished, the gardeners leveled the bed and the was tiered. The upper tier was the main
berm. Compost was mixed with native soils garden and the lower tier was for overflow.
to create the rain garden soil medium. Two The upper tier had an earthen berm but the
by four wood planks were laid out during lower tier had reinforced wooden wall.
planting to minimize soil compaction.
The public gardens at Landry Park
Some of the plants in this garden were installed August 7-11 by the Vermont The Dabb’s garden was designed to capture runoff
were donated by master gardeners Youth Conservation Corps crew. The town
from 2/3 of the roof . There was a lower tiered garden
(approximately 3 out of the 15 planted). The installed to capture any overflow from the top garden.
of Winooski excavated most of the gardens
garden was mulched with approximately two and created the curb cut for the entrance of
inch layer of aged mulch from the Intervale the gardens prior to installation. The town
Compost. The rain water was directed to also transported to the site all the gravel used
this garden through an extension pipe at- for the garden entrances and the walkway
tached to the rain gutter. The entrance of the from the baseball field. The compost and
garden was lined with pebbles to protect mulch was delivered to the site by Intervale
from erosion and to better disperse the wa- Compost.
ter.
On August 7, the first day at
Landry Park with the VYCC crew, Andrew
Gordon from the University of Vermont’s
Across the Fence TV program, came and
filmed the installation and interviewed Eric
Bailey from the city of Winooski, Sally
Dean, the master gardener involved in the
project and Jim Foster, a garden recipient.
On that same day, a reporter and photogra-
pher from the Burlington Free Press inter-
viewed the VYCC crew members and the
project coordinator Emma Melvin. This
article appeared in the Burlington Free Press
the following day August 8. The Across the
3. The rain water was directed to the Vermont Farm Show and is currently dis-
garden through an extension pipe connecting played at the State Extension office in Col-
to the down spout. A small rock pile was chester. The Across the Fence show and
created at the end of the extension pipe to the brochure is also available now on the
dissipate the flow into the garden. Approxi- Lake Champlain Sea Grant webpage. The
mately eight volunteers helped install this project was also spotlight in a presentation
garden. made to the New England Conservation
The last garden installed in the fall Districts at their annual meeting in Febru-
was at the Nocito property at 4 Pine Grove ary. A workshop on incorporating rain
Terrace. This garden infiltrated one fourth gardens and other low impact development
of the roof and was adjacent to the back strategies focused the Winooski Rain Gar-
deck. The garden was adjacent to the gutter den Project was presented at the Town Of-
and required little directing. This garden ficials Education Conference spring of
comprised mostly of bushes, most interest- 2007.
ingly blueberry bushes and some herbaceous Educational signs were designed
flowering plants. by the Maja Smith with the LCBP Wayside Rain Garden Sign to be posted at the public rain
Visits were made to the installed Exhibit Program. This fall the signs will be gardens.
gardens to assess for any problems and en- posted at the public gardens explaining the
sure proper functioning in the fall and the stormwater impact on streams and how rain was removed early enough by Emma Melvin
gardens function and reduce these impacts. and the volunteer master Sally Dean to incur
following spring and summer.
Identical signs will be posted at rain gardens no damage to the plants. Sediment depos-
Two rain garden tours were con- installed by Otter Creek, Poultney Met- ited into the garden is the largest mainte-
ducted in the fall of 2006 for interested mas- towee, and Rutland. nance issue with the North Street gardens.
ter gardeners, state employees, university
Maintenance Few of the drive ways located in the water-
faculty and students. 17 people attended the shed draining into the rain garden are gravel
tours. Two more tours were given in April All gardens were visited early or dirt. It is quite apparent that these drive-
2007 for the master gardeners and a Ver- spring to see if any damage was incurred ways are contributing enormous amounts of
mont Technical College horticultural class. over the winter. All gardens were function- sediment entering into the gardens. The
An presentation was made to the ing properly and were infiltrating spring driveways can be identified by the type of
Winooski City planning and development snow melt. gravel that appears within the garden. Large
review boards about the project and rain Plants were added to the North stones were added to the entrance to stabi-
gardens encouraging them to consider rain Street gardens. The North Street gardens lize the entrance. Much of the smaller
gardens and Low Impact development as a were impacted by a water main break above gravel was transported into the garden after
solution to manage the towns stormwater. the gardens on North Street that washed in the larger storms and the water main break.
large amounts of sediment. This sediment The gravel and sediment built up at the en-
An educational how- to poster was
covered the lower two gardens about 2 1/2 trance of the gardens were removed as part
created for municipalities and others inter-
inches deep. The upper garden received less of the route weeding. Mulch was stockpiled
ested. An informative brochure was created
sediment with only a thin layer of sediment at the city wastewater treatment plant and
about the project and was distributed at the
over sections of the garden. This sediment was used to mulch all the public gardens.
Residential Rain Gardens and Master Gardeners
This project pur- generously donated many of the plants used within the rain gar-
pose was to dem- dens installed in this project. This highly respected and active
onstrate the uses of group planted the seed of rain gardens in their local communi-
rain gardens as a ties. Stemming from this partnership a rain garden workshop
viable tool to man- was presented at the Annual Association of Professional Horti-
age stormwater in culturist meeting and rain gardens and the Winooski project was
an ultra urban envi- featured on the cover page of the Living Section of the Burling-
ronment. By part- ton Free Press in July 2007. As part of this projects partnership
nering with the master gardener program has been working with Lake Cham-
Master Gardeners plain Sea Grant to develop a plant list suitable for Vermont rain
program, this project was able to reach master gardeners gardens.
throughout the state and within Chittenden County. Master gar- Special thanks to Nancy Hullet, Sally Dean, Marc Conpanion,
deners helped the home owners choose the proper plants for Tage Lilja and Ann Pearce.
their garden and how to maintain a healthy garden. They also
4. dens, the total rain fall was used since resi-
dence noted that their rain gardens never
filled. For the Public gardens only storms 1
inch or less were used in the calculations.
Though rain gardens did infiltrate snow melt
this was not included in the calculations.
Winooski Rain Garden Project
Garden edging was added to the gardens to in which the stream drains into prior to it
reduce the weeds within the garden. Sally being piped underground. With the means
Dean has adopted the North Street garden available no flow measurements could be
made directly upstream of the North Street Figure 2. Winooski Rain Gardens
and has helped maintain these garden this
Infiltrated Stormwater
summer with Emma Melvin. She will con- rain gardens to assess the actual decrease in
tinue this maintenance in the following stormwater flow entering the stream. Esti- Garden Drainage Infiltrated
mates were made of decreased stormwater area Rain
years.
for each rain garden for the functioning pe- Foster 500 ft2 19,495 ft3
All plants that were planted at these riod of the garden by calculating the rain fall
gardens survived this year and will be moni- Dabb 850ft2 26,928 ft3
tored next year. Figure 1. Precipitation After Rain
Gardens Installed McCrea 500 ft2 18,020 ft3
The other Landry Park gardens Rain
were damaged during park construction. No Events Nocito ft2 7,920 ft3
maintenance was completed on these gar- Gardens Inches Above 1
Installed Date of Rain Inch North Street 32,292 ft2 1,051,750 ft3
dens due to the continued construction and
inability of the city securely say that these Aug-07 1.46 b
Wastewater 600 23,394 ft3
Jul-07 6.29 2
gardens would be maintained and restored Treatment
Jun-07 2.26 b
after construction.
May-07 1.95 b
The gardens located at the waste- Apr-07 3.79 1.27
water treatment plant were re-mulched at the Mar-07 Sediment and gravels washed into the rain garden
entrances at North Street. This is removed as part of
beginning of the season and weeded through Dec-07 3.84 1.74 the season maintenance.
the season. Most plants in these gardens Nov-07 2.62 b
came back this season. Nocito Oct-07 6.25 1.96
Dabbs Sep-06 3.22 b
Stormwater Reduction McCreas &
Landry Park Aug-06 4.36 1.5
Some stream flow monitoring was
Fosters &
completed after the garden installations.
Waste Water
Morehouse Brook is piped under ground for Treatment
much of its length. It is first piped under Plant Jul-07 2.95 b
ground at the industrial park near the head Total
waters and is piped under North Street and Rain 38.99
Landry Park. The flow measurements were and multiplying it by the drainage area of the
made at the point the stream reappeared rain garden (Figure 2). The precipitation
from underground just lower left corner of data used for this calculation was taken from
Landry Park and where it day-lights again at the NOAA National Weather Forecast Of-
Mallets Bay Avenue. Upstream measure- fice webpage for Burlington (Figure 1). The
ments were made but were hard to compare time period used does not include periods
to the downstream measurements due to the during the winter when the gardens were
industrial park’s stormwater detention pond filled with snow. For the residential gar-
5. Nocito garden has an assortment of shrubs including
summer sweet and blueberry bushes.
Winooski Rain Garden Locations
Public Garden Locations:
Landry Park-
3 gardens on North Street along Park fence
1 gardens within park adjacent to bleachers
1 garden within park adjacent to baseball field
dugout
Winooski Wastewater Treatment Plant-
2 gardens adjacent to parking lot
Private Garden Locations:
217 Mallets Bay Avenue
57 Cedar Street
103 North Street
4 Pine Grove Terrace
This project was funded by a Vermont Agency of Natural
Resources, Department of Conservation Non-point Source Pollution
Control Grant, and by the CSREES USDA New England Regional
Water Quality Project, award number USDA 00-51130-9775.
Survey Results and Comments
1) Have you seen pooling in your garden? Nocito: We love our garden! It performs great!
McCreas: Yes, I have seen pooling, but only in the middle of a 4) Have you talk to other people about rain gardens?
very heavy rain storm (remember, I also funnel water from the
McCreas: Yes, I talk to people about the rain garden ...... and
back roof into the garden, AND we built it a tad larger than was
thanks for the Free Press referral!
originally anticipated).
Foster: Constantly, a couple who I have talked to has put one in
Foster: No standing water at all.
or have plans too. People who talked to ask more questions about
Nocito: There has not been any pooling in our garden.
putting one.
2) Have all the plants survived? Nocito: Yes we have talked with other people about our garden.
McCreas: I lost one plant over last winter. 5) Do people ask you about your rain garden?
Foster: All survived
McCreas: Thanks to the Free Press article, lots of people ask me
Nocito: All of our plants survived beautifully
about my rain garden.
3) Are you satisfied with the gardens performance? Foster: No neighbors this year but neighbors on each side asked
McCreas: The garden is wonderful - it also supported a large last summer.
gaggle of bird-planted sunflowers all summer. The best display of Nocito: People cannot see ours unless they are in our backyard,
sunflowers I have EVER had. but typically if I bring it up they ask more about it.
Foster: Absolutely
6. Winooski Rain Garden Project,
protecting our waterways through gardening
Picutres taken during the Winooski Rain Garden
Porject.
University of Vermont
63 Carrigan Drive
Burlington, VT 05405
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Address
City, State Zip
