HomeMy WebLinkAboutA REPLAT OF LOTS 11 AND 12 OF EVERGREEN PARK THIRD FILING - 53 90 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTDRAINAGE REPORT
MATUKA COURT PROJECT
LOTS 11 AND 12, EVERGREEN PARK, THIRD FILING
PREPARED FOR
FORT COLLINS HOUSING AUTHORITY
PREPARED BY
STEWART & ASSOCIATES, INC.
DECEMBER 6, 1990
e.
Matuka Court is an existing cul-de-sac located on the south side of
Conifer Street and about one quarter mile west of North Lemay Avenue.
The existing development of the site consists of 4 buildings, a paved
street and parking areas and some grassed area. The drainage is from
north to south, and there are no offsite flows from Conifer Street onto
Matuka Court because of an existing cross .pan.
The existing runoff on Matuka Court flows to the south end of the cul-
de-sac, and then under the sidewalk through an existing chase. The
flow is then overland in a gradual swale which takes it to the boundary
of the property. There is no drainage outfall from the south boundary
of the property, so as it exists now, the runoff just puddles, and
trickles or seeps away. There is a proposed future drainage way along
this south boundary line which will carry the water east to an existing
ponding area.
The proposed development is an additional 4 plex building which will
be placed at the south end of Matuka Court. This new building will
be located on the existing outflow Swale, so an underground pipe will
be required to carry the runoff from the cul-de-sac to the south boundary
of the property. We plan to construct an area inlet in the new parking
area lying north of the new building. The runoff from the cul-de-sac
will pass through the existing sidewalk chase, and then run in a concrete
pan to the new area inlet. This area inlet will also serve to pick
up runoff from the parking lots. An, overflow swale to the south between
the buildings will limit the depth of any possible ponding at the area
inlet to 1.50.feet. The outflow pipe from the area inlet drains to
the south boundary of the property. Since, at this time, there is no
outflow for the pipe, a temporary bubbler will be necessary until the
proposed future drainage way is constructed.
The area inlet and pipe line are sized large enough to carry the 100
year storm flow from Matuka Court.
We are not providing any additional detention, because a large existing
pond has been constructed for the Evergreen Park area. This pond is
---I ocated-about-f i-ve - -hundred -feet east of Matuka Court. The -proposed
future drainage way running east along the south boundary of the Matuka
Court site will drain to the existing detention pond.
We have calculated the flows from the developed Matuka Court basin.
The 100 year flow is 5.7 c.f.s., which can be carried by a double grated
area inlet and a 15 inch outlet pipe.
Phillip Robinson, P.E. & L. S.
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