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CES NW
April 18, 2002
Mr. Gary Lampella
Building Official
City of Tigard
13125 SW Hall Boulevard
Tigard, Oregon 97223
RE: Cook Park Expansion Phase 2
Plan Submittal and Alternative Method Approval
Dear Mr. Lampella:
As you are aware, today we are submitting revised Architectural, Mechanical and
Electrical drawings for the Restroom /Storage Building, Restroom /Concession Building
and the Maintenance Building for the Cook Park Expansion Phase 2 project. Revisions
have been made addressing review comments regarding 100 -year flood impacts to the
structures.
In summary these revisions include:
Structural
Added openings and /or louvers to allow equalization of flood waters. Elevation
drawings show 100 -year flood plain levels for each building.
Electrical
Moved main electrical systems and panels above the 100 -year flood plain elevation. All
light switches were changed to ceiling mounted occupancy sensors, above the 100 -
year flood plain elevation. Quick disconnects and drops are used for any electrical
fr`�/r'yl��a n�
service below the 100 -year flood elevation. A ladder has been adde- ozp ac e- ss
to mezzanine level and electrical panels.
Mechanical /Plumbinq APR 1 d ?O[i?
CYn U HUARD
Grease Hood in the concession stand is above the 100 -year flood l e va W at SION er
heaters have been moved to mezzanine level.
CESNW,INC.
15573 SW BANGY RD., STE. 300 LAKE OSWEGO, OR 97035
503.968.6655 TEL 503.968.2595 FAX www.cesnw.com
Alternate Method Approval
In order to protect the sanitary sewer system, the following procedures - will be added to
the City's Park shut down and opening procedures:
Shut Down
1. Water supply will be shut off to each building.
2. Compression plugs will be installed at the downstream manhole for each building.
On the maintenance building, this will also isolate the oil /water separator.
3. Electrical power is shut down at the park.
Park Opening
1. All sewer lines are cleaned each year at opening. If a flood event has occurred, the
downstream manholes will be cleaned, compression plugs removed and sewer service
lines cleaned to each building.
Magnetic Locks on Restrooms
According to the suppliers, there are no UL approved magnetic lock sets available for
use in flood prone situations. The magnetic lock sets are a critical component to the
operation of the park and there are no other alternatives available. The City proposes
to replace any lock set damaged during a flood event as an alternate method.
If you have any further questions in this regard please give me a call.
Sincerely,
CESNW, INC.
/Of%
Anthony Weller, P.E., P.L.S.
Vice President
cc: John Roy, Property Manager, City of Tigard
Phil McCurdy, Phil McCurdy Architects
U 6 ,4 A
DIRECTOR'S INTERPRETATION h
RE: CONSTRUCTION WITHIN THE FLOODPLAIN (CHAPTER 18.775 /SENSITIVE LANDS)
BACKGROUND �- � kf w 1)
The Development Code Chapter 18.775 establishes standards for building in the floodplain.
Section 18.775.040 establishes general provisions for floodplain areas. Section
18.775.040.A. says: "Permit review. The appropriate review authority shall review all permit
applications to determine whether proposed building sites will be safe from flooding." The
Building Official has been historically considered the appropriate authority, working for the
Community Development Director.
Section 18.775.040.M. concerns Nonresidential Construction. It says that "New construction
and substantial improvements of any commercial, industrial, or other nonresidential structure
shall either have the lowest floor, including basement, elevated to the level of the base flood
elevation, or together with attendant utility and sanitary facilities, shall:
1. Be flood - proofed so that below the base flood level the structure is watertight with
walls substantially impermeable to the passage of water;
2. Have structural components capable of resisting hydrostatic and hydrodynamic loads
and effects of buoyancy;
3. Be certified by a registered professional engineer or architect that the design and
methods of construction are in accordance with accepted standards of practice for
meeting provisions of this subsection based on their development and /or review of the
structural design, specifications and plans. Such certification shall be provided to the
Building Official as set forth in Subsection 18.775.030.E.2.; and
4. Nonresidential structures that are elevated, not flood - proofed, must meet the same
standards for space below the lowest floor as described in 18.775.040.L.2. Applicants
flood - proofing nonresidential buildings shall be notified that flood insurance premiums
will be based on rates that are one fool below the flood - proofed level (e.g., a building .
constructed to the base flood level will be rated as one foot below that level)."
Other sections of Section 18.775.040 also relate to construction in the floodplain:
E. Resistant to flood damage. All new construction and substantial improvements,
including manufactured homes, shall be constructed with materials and utility
equipment resistant to flood damage.
F. Minimize flood damage. All new construction and substantial improvements, including
manufactured homes, shall be constructed using methods and practices that minimize
flood damage.
G. Equipment protection. Electrical, heating, ventilation, plumbing, and air - conditioning
equipment and other service facilities shall be designed and /or otherwise elevated or
located so as to prevent water from entering or accumulating within the components
during conditions of flooding.
H. Water supply systems. All new and replacement water supply systems shall be
designed to minimize or eliminate infiltration of floodwater into the system.
Page 1 of 2
Anchoring. All new construction, all manufactured homes and substantial
improvements shall be anchored to prevent flotation, collapse, or lateral movement of
the structure.
J. Sanitary sewerage systems. New and replacement sanitary sewerage systems shall
be designed to minimize or eliminate infiltration of floodwater into the systems and
discharge from the systems into floodwater.
DISCUSSION
The above standards include terms such as watertight, flood - proofed, substantially
impermeable, resistant to damage, minimize damage, prevent accumulation and minimize or
eliminate. Building practices vary and numerous alternatives exist to address such
terminology. The Uniform Building Code Appendix Chapter 31, "Special Construction,
Division 1, Flood Resistant Construction" has specific design and alternative specifications
that are nationally recognized in minimizing damage from flood water.
INTERPRETATION
The City of Tigard will utilize the Uniform Building Code Appendix Chapter 31, "Special
Construction, Division 1, Flood Resistant Construction" to address the structural requirements
of Section 18.775.040.
James N.P. Hendryx
Director of Community Development
Date
I: \curpin\ dick\ letters \interpretation_construction within the floodplain.doc
Page 2 of 2
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City of Tigard CIT O F TIGARD
13125 SW Hall Blvd Ave.
Tigard, Or 97224 . ORE
RE: Cook Park Expansion Phase II, Maintenance structure
The City of Tigard Building Division has reviewed the submitted building plans for the above
referenced address in accordance with the Oregon Structural Specialty Code (OSSC), 1998
edition and the Uniform Fire Code, 1997 edition as amended by Tualatin Valley Fire & Rescue.
Plans have been submitted for the construction of a Maintenance Building, housing, office,
storage and restroom on the first floor with a storage mezzanine above. Proposed construction is
in the flood plain of the Tualatin River. No cutting or welding is allowed do to occupancy class.
1) Buildings or structures erected with in a flood hazard zone shall have the lowest floor
including basement floors, located at or above the base flood elevation.
Exception: floors of buildings or structures that are used only for building access,
means of egress, foyers, storage, and parking garages may be below the base
flood elevation.
Plans currently show the finish floor elevation at 121.45' and the base flood elevation for the site
is 125.73'. The proposed structure is 4.28 feet below the base flood. Therefore limiting the use or
occupancy to one of the above permitted uses. Remove the office and restroom from the first
floor.
2) Protection of mechanical and electrical systems: Electrical equipment and heating; air
conditioning and other service facilities shall be either placed above the base flood elevation
or protected. Installation of electrical wiring and outlets, switches, junction boxes and panels
below the base flood elevation shall conform to the provisions of the electrical code for such
wet locations.
3) Enclosures below the base flood elevations shall be provided with vents, valves, or other
openings that will automatically equalize the lateral pressure of the waters acting on the
exterior of the wall surfaces. The bottom of the opening shall not be higher than 12 " inches
above the finished floor. Current plans and engineering do not address vents or any other
means to resist lateral pressure.
4) Elevation certification: A land surveyor, architect, or engineer licensed by the state shall
certify that the actual elevation in relationship to the base flood with the bottom of the lowest
floor or horizontal structural member.
5) . The mezzanine floor system has been designed for a 100 -psf live load. According to table 16-
A the mezzanine floor shall be designed to 125 -psf live load.
6) Provide engineered building plans for the metal building.
13125 SW Hall Blvd., Tigard, OR 97223 (503) 639 -4171 TDD (503) 684 -2772
7) Plans show combustible framing with in the structure. Draft and fire stops are required at
ceilings/floor and every 10' horizontally and vertically.
8) Overhead doors shall remain in the open position when equipment is running or provide
mechanical ventilation for the removal of fumes.
Current plans do not show compliance with code please revise and resubmit plans showing
compliance with
•
. If you have any.questions regarding this review, please contact me at (503) 369 -4171 ext. 392.
Sin y,
D.. 1 nes
' Examiner
Cc: Hap Watkins, Supervising Inspector
Building Inspectors
File
3/1/02 =d �r
City of Tigard CITY' OF TIG
13125 SW Hall Blvd Ave.
Tigard, Or 97224 OREG
RE: Cook Park Expansion Phase II, Maintenance structure
The City of Tigard Building Division has reviewed the submitted building plans for the above
referenced address in accordance with the Oregon Structural Specialty Code (OSSC), 1998
edition and the Uniform Fire Code, 1997 edition as amended by Tualatin Valley Fire & Rescue.
Plans have been submitted for the construction of a Maintenance Building, housing, office,
storage and restroom on the first floor with a storage mezzanine above. Proposed construction is
in the flood plain of the Tualatin River. No cutting or welding is allowed due to occupancy class.
1) Buildings or structures erected with in a flood hazard zone shall have the lowest floor
including basement floors, located at or above the base flood elevation.
Exception: floors of buildings or structures that are used only for building access,
means of egress, foyers, storage, and parking garages may be below the base
flood elevation.
Plans currently show the finish floor elevation at 121.45' and the base flood elevation for the site
is 125.73'. The proposed structure is 4.28 feet below the base flood. Therefore limiting the use or
occupancy to one of the above permitted uses. Remove the office and restroom from the first
floor.
2) Protection of mechanical and electrical systems: Electrical equipment and heating; air
conditioning and other service facilities shall be either placed above the base flood elevation
or protected. Installation of electrical wiring and outlets, switches, junction boxes and panels
below the base flood elevation shall conform to the provisions of the electrical code for such
wet locations.
3) Sanitary sewage system, shall be designed to minimize or eliminate infiltration of floodwater
into the system and discharge from the system into floodwater. Current plans show floor
drains with oil separators in the floor of the garage area and restroom located on the first
floor. (Oil separators by design in the event of flooding will release oil and other products
into the floodwaters).
4) Water Supply System all water supply systems shall be designed to minimize or eliminate
infiltration of floodwater into the system.
5) Enclosures below the base flood elevations shall be provided with vents, valves, or other
openings that will automatically equalize the lateral pressure of the waters acting on the
exterior of the wall surfaces. The bottom of the opening shall not be higher than 12 " inches
above the finished floor. Current plans and engineering do not address vents or any other
means to resist lateral pressure.
13125 SW Hall Blvd., Tigard, OR 97223 (503) 639 -4171 TDD (503) 684 -2772
6) Elevation certification: A land surveyor, architect, or engineer licensed by the state shall
certify that the actual elevation in relationship to the base flood with the bottom of the lowest
floor or horizontal structural member. A benchmark shall be set prior to construction. And
fmal elevation certificate prior to building fmal.
7) The mezzanine floor system has been designed for a 100 -psf live load. According to table 16-
A the mezzanine floor shall be designed to 125 -psf live load for light storage.
8) Provide engineered building plans for the metal building.
9) Plans show combustible framing with in the structure: Draft and fire stops are required at
ceilings /floor and every 10' horizontally and vertically.
10) Overhead doors shall remain in the open position when equipment is running or provide
mechanical ventilation for the removal of fumes.
Current plans do not show compliance with code please revise and resubmit plans showing
compliance with code.
If you have any questions regarding this review, please contact me at (503) 369 -4171 ext. 392.
S' cerel
D yl nes
lans Examiner
Cc: Hap Watkins, Supervising Inspector
Building Inspectors
File