Villages CC 1-3-CS 910617June 17, 1991
Ms. Shohre Daneshmand. P.E.
Acting City Engineer
City of Coppell
255 Parkway
Coppell, Texas 75019
RE:
Proposed Gazebo
118 Winding Hollow Lane,
Coppell, Texas
Dear Ms. Daneshmand:
At the request of my client, Larry Howe, I have reviewed the following
information <copies attached) pertaining to his intention to construct a
gazebo on the re~erenced property:
1)
Detail of the proposed six-sided structure (10 feet across at the
center o~ two opposing sides>,indicating 4×4 wooden pier supports at
each corner and at the center. Open steps will be located on one side
o~ the structure.
2) Boundary survey plat of the subject property~
Figure VI-7 from the preliminary floodplain study prepared by Albert
H. Half~ Associates, Inc.,
Onsite observations o¥ the general area of the proposed structure
revealed the following:
1)
The owner has recently removed a 50" diameter tree from the
northeast corner of the property. The stump has been removed to a
point that it is flush with the ground. The owner has indicated his
intention to remove an additional tree, 12" in diameter, at the
southeast corner of the property.
2)
proposed for the structure is 574.4, indicating that the 100 year
water surface elevation of 576 will produce a depth of 1.6 feet at
this point.
A natural gas transmission main (50' easement) crosses the back
0ortion of the property diagonally northwest to southeast. The line
has been located on the ground by Lone Star Gas Co.
4)
A 48"diameter storm pipe runs west to east under the property line
common to the subject property and the property to the south. A 7.5'
p. o. box 334 coppell, texas 75019 {214) 241-0336
Ms. Shohre Daneshmand, P.E.
June 17,1991
Page 2
drainage easement runs along the south property line for this
purpose.
Based on my review and above observations, the loss of cross section area
for flood flow due to the piers and steps of the proposed gazebo, will be
adequately offset by the removal of the two trees. With the following
provisions, the proposed structure will not pose a threat o~ increased
flooding during the 100 year and lesser floods:
1)
Lone Star Gas Co. has indicated that the structure must be located
outside of it's easements. The structure should also be located
outside of the drainage easement.
2)
The bottom o~ the lowest horizontal structural member o~ the gazebo
should be located 1.0 foot above the 100 year ~lood elevation. This
corresponds to an elevation o~ 577.07 for which a survey marker has
been place in the general location.
The bottom of the gazebo should not be enclosed with permanent
attachments~ but rather be left open to permit flow under the
structure.
The piers should be constructed o~ rot-resistant materials and be
placed a minimum of 5.0 Seer into the ground. The piers should be
concrete encased. The pier holes should be over-excavated to allow
a minimum concrete cover of 1" at all points~ and the upper one foot of
each hole should be over-excavated to permit a minimum cover o~ 2.5".
For example, ~or piers which are 4x4 (5.5" × 5.5", ~inished), the upper
one foot of the hole should be 10" in diameter, with the lower portion
being 7" in diameter.
you have any questions, please do not hesitate to call.
Sincerely,
O'BRIEN ENGINEERING
cc: Mr. Larry Ho~e