Northlake WE P10C-CS 990211 MEMORANDUM
To: Mike Martin, P.E., Assistant Directoxeof Engineering
From: Doug Stevens, Engineering Technician
RE: Drainage problem at 413 Willet Drive/f'lorq4x!v,J~
Date: February 11, 1999
On Tuesday, February 9, 1999 I received a phone call from Darrell Michiels of 413
Willet Drive complaining of mud and water that had washed into his garage and swimming
pool during a heavy rain on the previous Saturday night. Upon meeting Mr. Michiels at his
resident, I observed the alley adjacent to his property made an approximate 90° bend coming
off a fairly steep grade. Physically it did not appear that the alley had been constructed
properly around the outside of the bend as to contain the water as it made it turn. Therefore, I
took pictures of the alley and of the mud both inside Mr. Michiels garage and pool and
explained to Mr. Michiels that I would return to shoot elevations in the area of question.
Attached you will find a copy of the alley profiles for alley "G" and the drainage area
map for Northlake Woodlands East No. 10C, a copy of the standard detail for an alley, and a
copy of the elevations that were shot. Upon viewing the elevations, several points should be
brought out.
1. The starting elevation was established from the invert elevation of alley
"G" profile at Station 6+31.80. That elevation was 462.23.
2. At the widest point in the bend of the alley the standard details require a
10" (0.83) difference from the centerline invert. The actual difference
observed is only 0.24 or not quite 3".
3. In addition, we did not observe adherence to the 5" (0.42) invert
requirement at any point within the range of our study.
4. Mr. Michiels driveway also falls away from the alley allowing the water
to continue on it path of least resistance. There exists an expansion joint
5-foot away from the alley. This would allow a small area of his
driveway to be rebuilt if necessary.
5. It should be noted that Northlake Woodlands Phase 10C is still in it
maintenance period until May 1, 1999. The paving contractor was Site
Concrete, Inc.
Mr. Michiels called on Wednesday to say he was sending you and Greg Jones a letter
explaining his situation. I did explain to Mr. Michiels, in the field, that the city would not be
responsible for damage and more likely it would be the contractor or developer. If you should
need additional information on this matter, please contact me.
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DOUG $. - INSTR.
GARRETH C. - ROD
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NOTE:ALLEY PAVING TO BE PLACED IN SHADED AREA
WHEN SCREENING ,LL IS ALONG PROPERTY LINE. 6' VARIES
INSIDE.~'EDGEI' i'"'~-°[ OUTSIDE ED
15' OF /IJ. LE~Y-~J OF ALL[
/---PROPERTY LINE /--SCREENING WALL
§ ~ SECTION A-A
'-0 ~ /---INVERT
'
, & __ PROPERTY LINE
PROPERTY
r'~= 7~e- 9°e
L__'~____ 40' RADIUS ~-- : O'-
TYPICAL
'"'~TH A B
#) -
I0' 2.5' 6.0' : B E! _
I~" 4.0' 7.5' ~ i -- i
w
16' 2.0' 8.0' A I0' A
ALLEY TURN 75°-90°
ALLEY TURN 60°-