HomeMy WebLinkAboutUpdated Plan email 2.28.2020
Grant, Kelly
From:Daniel A. Ojala PE, PLS <downcape@downcape.com>
Sent:Friday, February 28, 2020 11:27 AM
To:Grant, Kelly
Cc:Priscilla@downcape.com; 'A. M. Wilson Associates'
Subject:Giglio SE83-2125
Attachments:17-147 Giglio Site Plan rev 2-27-20.pdf
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RE: SE83-2525 Giglio
Dear Commission Members:
Attached is a revised plan responsive to the Commission’s requests, and also responds to the
AM Wilson letter dated 2-25-2020.
Please note that the roadway in this area is pitched from North to South, and there are
hundreds of feet of street drainage running past and onto the sites.
There have been historic drainage problems in this area, and a very high seasonal
groundwater level which had contributed to wet crawlspaces and the drainage issues due
in part to sump pump discharge.
In general having a yard lower than the street invites road runoff onto the properties, raising
the grades slightly adjacent the layout is suggested to prevent street runoff from entering the
private properties adjacent the roadway surface.
As can be seen on the Site Plan revised 2-27-2020 we have extended the rear grouted
cinderblock retaining wall to blend in with the existing rear grade and created a larger grass
lined swale on the locus side of the wall to ensure the runoff from the rear of the property is
properly infiltrated onsite. There is no need to remove the wall and fill, this will only recreate
the same set of condition a couple feet lower, and closer to the adjusted groundwater.
We are removing the paved driveway, pulling it back a full 8’ from the lot line and replacing
with pervious gravel, and creating a three to one slope down to a six inch deep swale along
the lot line between the retaining wall and the front lot line.
To ensure the runoff is clearly demarcated between the properties, a rigid plastic landscape
edging is proposed with a three inch reveal in this area.
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This edging will help deflect the abutters sump pump discharge which is inches from our
property, and will help ensure this discharge does not enter the swale on locus and overload
the swale.
A section through the swale is shown for clarity. Since only a tiny amount of walk and slope is
pitched into this swale, the size is adequate to ensure this small amount of runoff stays on
locus.
The roof is connected to subsurface leaching, and a deep gravel base under the concrete
footing on the grouted and reinforced cinder block retaining wall helps ensure runoff stays
on our side of the wall.
Although not a conservation issue, please note it is proposed the cinder block retaining wall
will be finished with a solid capstone and the face of the wall finished in stucco which is the
same material as the abutters house, so the aesthetics should match nicely.
I would also note that the recent loam placed on this abutting property is compacted and
holding water, it should be scarified and seed added and watered sufficiently to germinate
a healthy lawn which would significantly increase the infiltration in that area.
Daniel A. Ojala PE, PLS
down cape engineering, inc.
939 Main St. Yarmouthport, MA
1-508-362-4541 x106
1-508-362-9880 fax
downcape@downcape.com
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