Reynoldsburg Rain Garden
Mark McKenzie
Center. The garden is located just off the Northeast side of the
parking lot north of the Senior Center building. There is a little
shed at the northeast edge of the parking lot and the rain garden is
just to the east of the shed.
Just looking at it, I have some questions. The garden is situated near
what appears to be the high point of that piece of land. I can't see
where anything will drain into the rain garden. The parking lot slopes
down to the west. The Senior Center building is separated from the rain
garden by the parking lot and there doesn't appear to be any piping to
carry rainwater from the roof to the garden.
When I stopped by on Tuesday, there was a small diameter garden hose
running from the Senior Center to a sprinkler in the garden. I have
no idea what the rate of flow was or how long they had been watering the
garden, but at the time of my visit there were several inches of
standing water in the bottom of the bowl of the garden.
I thought I understood the principles of rain gardens. After seeing
Reynoldsburg's rain garden I must have been thinking wrong. Can anyone
else make sense of this?
Thanks,
Mark
Kurt Keljo
Inasmuch as I helped design the rain garden, perhaps I can be of help. The parking lot has its own watersheds and does not all flow in one direction. Much of the flow is to the north and west. However, there is a section of the parking lot that does flow to the northeast. There may be some water from the roof that flows in that direction as well, but it is hard to tell for sure.
The garden at the Senior Center is designed to receive the rain water that flows from that NE corner of the parking lot. There will be a drain intercepting the flow that will direct the water into the garden. The hope is that the garden will reduce the puddle that forms at the low point of the sidewalk--perhaps even eliminate it at times. There are times when there is enough rain to cause Blacklick to back up into the flood plain. At other times, water seems to just collect in the flood plain there. Under those conditions, the rain garden will not help. It will only help when a significant portion of the water in the puddle comes from the parking lot.
When water does flow into the garden, it is designed to drain within 24 hours. Even if the garden is filled to the edge (approximately 8" deep), the water should percolate into the soil within 24 hours. That way, any mosquito eggs laid in the water would not have time to hatch. The size of the garden should allow it to contain the water during the vast majority of rain storms in Central Ohio. The size of the drainage area and the speed with which the water drains into the ground determines the size of the garden. It was a bit hard to determine how large an area actually drains to that corner of the lot, so it will be interesting to see whether or not the size is appropriate.I am curious to see how it will function, once it is all finished.
Hopefully, this helps explain things a bit in the meantime.
Kurt
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Mark McKenzie
Conceptually, something is wrong here. Check for yourself, it is
easy to do.
Take a carpenter's level and check the slope of the parking lot and
then step off the area. The paved area of the parking lot with any
eastern slope is less than 400 square feet. Even this area, however,
has about a five to one ratio of north to east slope. This is just the
area directly south of the little shed at the northeast corner of the
parking lot. Also, compared to the paved area of the pathway
(not parking lot) leading down to the puddle region, the east sloping
parking lot is insignificant.
With so little runoff entering the "rain" garden, I have no doubt that
it can handle the water. I do have some concern that an already
overloaded Parks and Rec staff can keep up with the "garden"
maintenance.
Now I wonder where the drain is going to be installed and how large the
drain will be.
Mark