Report (9) 15575 SW Sequoia
Parkway Suite 140
Portland, OR 97224
90
CONSULTING August 31, 2004
ENGINEERS, INC
City of Tigard
13125 SW Hall Blvd
Tigard, OR 97223
Attn: Hap Watkins
Building Division
Re: Tigard High School Renovation Project Stormwater Facilities
CUP2004 -00001 `�
Dear Hap:
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The engineering design for stormwater quality at Tigard High School incorporated the following:
1. A single new filter catch basins manufactured by Stormwater Management, Inc. to provide
water quality for the new impervious area. (It should be noted that an alternate (existing)
area was selected for the new basin in lieu of the actual new paving. The new paving was
mostly courtyard sidewalks with multiple small drains. A larger paved vehicle area was
selected as an opportunity to provide water quality in a more needed area.)
2. For the construction access road into the site from SW 85 a filter grass strip was provided
for biofiltration of runoff from the road. Detention was provided by 300 linear feet of
underground perf pipe and a flow control manhole.
I visited the site at various stages of construction and confirm that the installation of the quality and
detention facilities are in conformance with the design and specifications.
Sincer:
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Mark Wharry, P.E.
Principal
c: Brian Greenwood / DOWA
Craig Marcus / Cornerstone
O:\2403 TTSD- TigardHS \DOCS\LETTER \083105hw wpd
503 / 226 -3921
fax: '226 -3926