Guest Post: NVCC Rain Collection Project

By Dan Culligan

 A group of students from Naugatuck Valley Community College, together with NOFA, recently designed and constructed a rain collection system on the campus of NVCC. Under the direction of Jenna Messier (Organic Land Care Program Director: NOFA) and Mike Schwartz (Academic Assistant of Horticulture: NVCC), the students (Ben Carroll, Kyle Denny, and Dan Culligan) were responsible for organizing materials and constructing the system. The primary goal of this project was to capture as much runoff as possible from the impermeable surfaces on campus and keep it from entering into Welton Brooke, Hop Brooke, the Naugatuck River, the Housatonic River and ultimately Long Island Sound during a rain event. Of course a secondary benefit of the project was the utilization of the captured storm water for watering gardens around the campus, thereby diminishing the schools use of the municipal water supply.  

Wading across the pond to install downspout underneath walkway

The team installing pipe

            In planning for this project, the group took into consideration a number of environmental factors that would influence the design and placement of the rain water collection system.  One of the factors that had been considered was the surface from which the water is collected. This meant that ample water would need to collect on the surface during a rainstorm to justify having the system in that particular area. The location of the system was also critical; because it had to be in a place where the rain water runoff was entering a waterway that would eventually travel into the Long Island sound. The holding capacity of the collection tank and the distance it is away from the nearest waterway is also critical; in the event that the system reached full capacity and overflowed there needed to be ample distance and other permeable surfaces surrounding for the excess water to enter the ground first.

The way to calculate approximate amount of water runoff in gallons on any impermeable surface is to use this equation: Harvested Water = Catchment Area (ft2) x Rainfall Depth (in.) x 0.623 Conversion factor.  Although the goal is to reduce storm water runoff, other unintentional benefits exist. Water conservation is a positive outcome and is also especially important for large institutions such as NVCC due to the sheer volume of people attending the school. In 2010, there were approximately 7,000 students attending the college. A large student body combined with thirteen horticulture gardens, numerous landscaped areas, 4 greenhouses and the Tamarack Arboretum command a substantial amount of water usage.

The first step in the construction process was to choose a location where storm water runoff could be diverted and collected. Upon studying the existing layout of the campus, the decision was made to make use of an elevated concrete pedestrian bridge that was discharging nearly 100% of the storm water that hit it directly into Welton Brook, which is the body of water the bridge goes over.  The location and engineering of the bridge along with its surrounding topography made this location a very obvious place for a water catchment system to be installed and utilized. The bridge starts near the main entrance of the school and ends at the entrance to the student center building. The dimensions of the walkway are approximately 130’ x 12.5’. The bridge was equipped with drains to prevent water buildup on the surface and freezing in the winter. The problem was that the drains were open on the bottom and spilled out directly into or very near the edge of Welton Brook and the pond it creates right below the bridge. The group decided that utilizing the existing drain structures in this location was the most practical way to design the catchment system. Consideration was taken to optimize cost, labor intensity, and collection volume based on the surface area, the location of the walkway and the existing configuration of the drains. This arrangement allowed for a relatively simple and effective design.

Pipe under walkway that will bring water to 550 gallon catchment tank

Once the targeted area was established, the next step was to design the system itself and estimate the cost for materials. In a one inch rainstorm there is a potential of collecting over 1,000 gallons of water. The collection basin used was a 550 gallon plastic water tank, and the system was made predominately out of PVC pipe due to its availability and budget friendly pricing. Some simple drain pipe extensions were attached to each of the five existing drains on the bridge, and then tied into one single main drain line using elbow and Tee connectors. All fittings were glued together to ensure

security and maintain a water tight seal.  Metal straps were screwed into the concrete, which support the pipes under the drains. The actual construction of the project took the group approximately four days to complete, costing under $1000 in materials.

When the campus experienced its first rainstorm with the new system in place it was found that in less than a day of heavy rain the entire basin had been filled. This means that 550 gallons of storm water had been successfully withheld from entering the surrounding waterways which has been raising concern amongst environmentalists in recent years.  That stored water will now be used by the college to irrigate at least two of its horticultural gardens located within a garden hose length from the tank.

The team intentionally designed the system to allow for additional tanks to be joined to the one they installed in order to collect and store even more water.  During the primary survey of the campus there were also several other locations identified where impermeable surfaces come into close contact or discharge directly into Welton Brook.  These locations can easily be used in the future as sites for rain water collection systems. The team made a list of these locations and provided it to the campus director of facilities.

              The work done at NVCC shows how a small investment can make a big difference.  This hopefully can serve as an example for other institutions, industrial buildings and residential homes to not only reduce the amount of runoff going into Long Island Sound but also to be better stewards of the water resources they have available to them for free, which can be applied to a multitude of creative uses. Through the construction of this system students of the college who are being trained for the green industry now have a great example of how a storm water collection system works and the benefits of including similar systems in their own projects in the future.

550 gallon tank that will catch rain water from walkway above campus pond

Downspout leading to catchment tank

   

Rain Garden is Finished at Three Rivers Community College

Sediment capture at front of rain garden

We completed the rain garden at Three Rivers Community College on Saturday, June 6th and it came out perfectly!
When Jenna and I arrived, the first thing we noticed was the sediment capture behind the curb cut. As water from the adjacent parking lot enters the rain garden, sediment is deposited on the flagstones and the water freely flows into the basin.


 Planting went very smoothly as the bio infiltration soil media was very easy to work with. Once we started, it only took a couple of hours to get everything in the ground. We gad a good work crew including Jenna and myself, Diba Khan-Bureau and her two children, and students Bobbi DesRoche, Chelsea Dubreuil, Nic Tedesco, Michael O'Connor, Troy Wood, and Jennifer Messerly. All the plants were purchased from Petie Reed of Perennial Harmony Garden Center in Waterford.

You can view Jenna's design and plant list below

The work crew for the day!

One thing that we did not anticipate was a deer issue! Jenna spotted some deer tracks in the garden before we started working which can be a huge problem! We decided that we had to put some deer fencing up after we finished up the rain garden to protect our plants.

Putting up deer fencing around completed rain garden

We will be checking in on the rain garden every couple of weeks and the students at TRCC will be caring for the rain garden throughout the summer while they work on their raised-bed vegetable gardens.

Garden design and plant list below:

Rain Garden Excavation at Three Rivers Community College

Yesterday was excavation day at Three Rivers Community College. Jenna Messier, Mike Deitz, the contractor Jim Benjamin Sr., his son, Jim Jr., and I were there all day to prep the site for the June 6th planting. Professor Diba Khan-Bureau and a few of her students were on site in the afternoon to watch and document the project.

Mike overseeing the dig!

At TRCC, we had to make a curb cut, dig the basin, install an overflow pipe, and create a sediment barrier. The goal of this project is to divert storm water from the adjacent parking into the rain garden and away from the storm drain.

Here are some highlights from yesterday:

The first step in the excavation process was removing soil to create the depression where storm water will be stored for a short period of time before draining into the ground. For this specific site, we excavated about 14 inches below grade, since we had electrical conduit at 18 inches below grade.

Jim Jr. making the curb cut

Secondly, we made the curb cut. This particular cut was strategically placed next to the storm drain so that all of the storm water from the adjacent parking lot would enter the garden before it reaches the drain.

Mike again! Installing the platform

We then built a platform at the entrance of the curb cut and installed cement patio blocks to catch sediment from the parking lot before it can enter the garden. This will allow for easy clean-up in Spring, by taking a flat shovel and scooping out the sand from the winter maintenance.

Drainage pipe!

After installing the platform, we laid an over-flow pipe at the base of the garden that will drain excess water into an adjacent wooded area in the event of a large rain storm that will discharge more water than the garden can handle.







Lastly, we filled in the basin with beautiful soil making sure to keep a slight depression that will temporarily store storm water!

The rain garden is ready for planting on June 6th!

Jenna and Mike discussing some last-minute details

We will be putting together a full step-by-step PDF which will show the entire process and can be used by anyone for teaching or practical purposes. 

Rain Garden Progress at Naugatuck Valley Community College

Jenna and I just checked in this morning at NVCC to see how the rain garden plants were coming along. It finally rained last night. Fortunately, Mike Schwartz of NVCC has been watering to plants and helping them establish due to the lack of rain. I'm glad to say that the plants are growing well and establishing themselves. The front of the rip rap has accumulated significant sediment which indicates that storm water is flowing into the garden. However, one problem presented itself -- the entire garden was full of golden rod!

The front of the rip rap with sediment from the rain storm

Large view of rain garden with milk weed and golden rod

Common Milk Weed

The golden rod presents some advantages and disadvantages in the rain garden. On one hand, they do add more plants to the basin and its banks so that more water will be diverted from the storm water outlet. The milk weed is great to have as they provide a habitat for monarch butterflies. On the other hand, the plants that were chosen for the garden must now compete for sunlight, soil, and water. Jenna and I did a couple hours of weeding to give our selected plants more room. We'll check in again in a month or so. We are hoping that as the grasses, ferns, and other plants establish themselves more, the golden rod will be less of an issue.

As for the rain garden plants themselves, they are starting to look very nice. Some have even started to bloom!

Baptista australis in bloom

Ostrich Fern

Tall Panic Grass

Joy Pye Weed

Bio-retention media

Here is some helpful information from Rich Simcich of Agresource Inc:

When designing a bio-retention an architect or engineer must calculate the volume of water the basin must filter for a 50-100 year storm. The square footage, depth of the media, and soil physical properties must be considered. Agresource will meet any specification for raingarden or Bio-retention soils but provide our own bio-retention media that works well in New England. See attached analysis.  

It consists of 50% uniform coarse sand, 20% sandy loam and 30% leaf compost. The proportions are put together and mixed with a mechanical mixer which will produce a media that will infiltrate greater than 2 inches per hour and contain 2.5% to 6% organic matter. The choice of sand is the key. The fines fraction of the media, particle that pass .15mm sieve, must be less than 20% to reduce compaction and increase infiltration. The organic matter content in the soil is important to nourish plants and break down hydrocarbons commonly found in storm water runoff. Too much compost can reduce hydraulic conductivity. There is a balance of particle distribution or soil texture and organic matter content.

Bio-retention basins that drain too quickly will not remove contaminates they were design to remove and will not support plant life during dry summer months. If you have any question please call me to discuss.

Rich Simcich

Click here for specification manual

Preparing for Excavation at Three Rivers Community College

Looking east toward the garden

Jenna and Mike

We are in the process of planning the rain garden at Three Rivers Community College. Mike Deitz of UConn NEMO (Non-Point Source Education for Municipal Officials) has come up with a cross section diagram and an overhead diagram of the rain garden.

Jenna went out to TRCC to meet with Mike Deitz and the contractor last week. After looking at many site maps, we found electric lines marked within the area of the rain garden so they had to dig a trench to see if wires were indeed present.
                                                    

Found the conduits. Do not try this at home!

This is one of the less sexy parts of the job!

Sure enough, 18 inches below the soil, there were two conduits--one for the electric lines and one for the security lines. The contractor now knows where to avoid when installing the drainage pipe at the basin of the garden (around 14 inches deep).

There are many steps prior to installing a large rain garden in an area that has pre-existing  infrastructure. Like Naugatuck Valley Community College, students will be designing the garden and choosing its plants. Prior to meeting with the students, Jenna went out to Perennial Harmony Garden Center in Waterford to get inspired and look at plant choices. Here is a picture of Petie Reed, AOLCP, and her partner, Rich, owners of the garden center .

Petie and Rich from Perennial Harmony

Cross section of rain garden

Rain garden area in green

The Rain Garden at NVCC is Complete!

Students planting

We finished planting the rain garden at Naugatuck Valley Community College on Monday, April 28, 2015 and it came out beautifully! We worked with the diverse and well thought out plant selection and design that the students had created earlier in the semester. All of the plants came from Earth Tones Native Plant Nursery and Landscape. A few of those plants included Baptista Australis (Blue Wild Indigo), Hibiscus Moscheutos (Rose Mallow), and Panicum Virgatum (Switch Grass). Unfortunately, we will not be able to see the plants in bloom for another several months. For now, they are still coming out of dormancy as you can see from the picture below with Jenna.  Make sure to keep reading this blog to see pictures of the rain garden after the plants have bloomed! Jenna and I will be heading up to NVCC periodically to check on the rain garden's progress!

Baptista Australis (Blue Wild Indigo)
 in bloom

Jenna in front of completed rain garden

Hibiscus Moscheutos (Rose Mallow)
 in bloom

Plants laid out before planting

Planting went fairly quickly as all the students in the class came down to help. Prior to the student's arrival, Jenna, Mike, and I created a type of rip rap out of river jacks to slow water coming into the rain garden from the curb cut. Mike had laid out all the plants in their intended spots prior to planting and had created very nice rock formation near the inflow and outflow pipes of the garden. After all the plants were in their places, we covered them with pots (its very easy to lose the little plugs once they are planted) and mulched the entire rain garden.

Rip rap from curb cut to rain garden

Rock formation at outflow pipe

We are so pleased with the way everything came out. Now go out and plant your rain gardens!

Jeremy