Super-Typhoon Pongsona; Damage Assessment Report
On Sunday, December 8, 2002, Guam was scheduled to observe Our Lady of Camarin Day, the island's patron saint. Instead, after developing for five days, Super-Typhoon Pongsona struck the Island of Guam. This storm had intensified as it tracked some 1,200 miles towards the Mariana Islands (see attached map), generating sustained winds of 150 mph with gusts exceeding 180 mph, depending on location. Storm surge and wave run-up also caused extensive damage along the shoreline. The combination of winds and waves created damage of such a magnitude that this typhoon has been labeled as the worst storm to hit Guam in living memory, a century storm.
The War in the Pacific (WAPA), National Historical Park (Site Map attached) had received extensive damage from this super-typhoon (see attached NPS damage report). Facilities along the shoreline, particularly the Haloda Building housing the Park Headquarters, World War II museum and Visitor's Center, and the Asan Beach Unit, were heavily damaged by wave action. The Haloda Building is currently vacated and re-occupation is not recommended due to various problems as described in this report. The Asan Beach will require re-establishment of shoreline embankment, parking lot repaving and possibly stone revetment repairs. Fortunately this park did not contain buildings or structures near the surf zone although the repairs that are identified may be costly. Other park units including the Maintenance facility, Piti Guns, Asan Overlook, Ga'an Point, Apaca Point, and Fonte Plateau suffered mostly from wind and rain damage. The USDOI National Park Service contracted with Engineering Solutions, Inc. (ESI), to perform an assessment of the typhoon damages to the WAPA park facilities and develop a cost estimate for repairs. The Guam based team of Winzler & Kelly Consulting Engineers, under subcontract to ESI, mobilized on site and assessed park damage on December 19, 2002. A preliminary assessment report (without costs) was transmitted to NPS on December 31, 2002. A pre-final report was transmitted on January 20, 2003. The draft final assessment report contained herein is based in part on NPS review comments and is due for submission by March 01, 2003.
A detailed description of the damages, representative photographs and cost estimates are included in this report. The total cost of typhoon damage repairs for the entire WAPA site is estimated to be in excess of $ 1,421,600.
On Thursday December 19, 2002 the Winzler & Kelly team made a field inspection of three facilities operated by the National Park Service on Guam (see location and site map). These facilities had suffered varying degrees of damage from Super-Typhoon Pongsona, on Sunday December 8, 2002 (a typhoon tracking map is attached). This assessment was performed to document the extent of damages incurred and includes cost estimates for the repairs. Also, at that time, representative photographs of the damage were provided by the NPS and are included as an appendix to this report.
The W&K team consisted of the following personnel: Fred A. Smith, Asia-Pacific Region Manager; Andrew W. Smith, Civil Engineer; John Setiadi, Architect; Conrado Vales, Mechanical Engineer; and Wayne Wixon, Electrical Engineer. The team was accompanied by the WAPA Park Superintendent, Eric J. Brunnemann; the WAPA maintenance worker, Jim Powell; WAPA Museum Curator, Terry Duchesne; and Bill Vines from NPS Hawaii.
The facilities that were inspected on December 19th consist of the Haloda Building which contains the WAPA Park Headquarters, the museum collection and the T. Stell Newman Visitor Center; and the Asan Point Maintenance Complex and Comfort Station area including the park grounds. On Friday December 27th Park Superintendent Brunnemann and Andrew Smith made site inspections to the park facilities at Ga'an Point and Apaca Point. On January 02, 2003 these two individuals also inspected the Asan Bay Overlook and Fonte Plateau site.
Damage Assessment Summary
The Haloda Building received extensive non-structural damage from wave run-up due to its proximity on the beach. One building column was noted to have a crack that apparently penetrates completely through the concrete, but this is not considered to be serious damage to the building's structural concrete frame. The building's main electrical service and distribution panels in the lower level parking garage were heavily damaged by wave surge. The government owned electrical equipment was removed by NPS personnel after the site inspection. The Visitor Center's exhibits and NPS offices were also badly damaged by wind driven rain intruding through broken windows and afterward because of no power to de-humidify and dry out interior moisture. All NPS property has been removed from the building (see attached newspaper article), however, the cost of boxing, moving and storage for these items, building security and other costs related to storm damage that have been incurred directly by the Park Service are not included here. Mold, mildew and fungus in the building are issues raised later in this report. The asphalt parking lot that is adjacent to the Haloda building was completely obliterated by wave run-up washing out the pavement. The pavement and base course is gone up to the roadway, leaving only beach sand. This area is Park property that cannot be used.
The Asan Point Maintenance Complex received relatively light damage from the 180 mph winds. A side door blew in and water penetrated into ceiling mounted light fixtures with some wind and water damage inside the maintenance office and storage area. The roof vents (3 each) were blown off, and the building air conditioner was damaged. A 20 feet long office trailer was blown off its concrete pedestals damaging its utility services. Six vehicles parked in the maintenance complex received varying degrees of damage. The perimeter chain link fence (8 feet high) was partially knocked down (150 feet) and the 15 foot long sliding gates damaged.
The Asan Beach Comfort Station did not appear to receive any significant damage but the sewage lift station pumps will need replacing. These 4-inch grinder pumps were filled with saltwater and do not work. The adjacent park had extensive wind and wave damage. Approximately 200 coconut trees were killed when their tops snapped off. The asphalt parking lot was torn up, a section of concrete paved walkway (12 feet wide by 30 feet long) washed out and hundreds of cubic yards of sand and coral washed up onto the grass. This material came from embankment along the shoreline (at the edge of the sandy beach area) that's approximately 1,000 feet long, 10 feet wide and 4 feet deep, with a total volume of 1,480 cubic yards to be reinstated. A slope stabilization project along the shoreline may consist of placing stone rip-rap over a geotextile material for 1,000 feet along the embankment.
The Ga'an Point and Apaca Point facilities being smaller and with a different exposure than Asan (westerly vs. northerly) had received relatively less damage. Work at these two units involves mostly the clean-up of debris, minor repairs, and replacement of vegetation. This is similar for the Asan Point Overlook, and Fonte Plateau.
The Piti Guns had considerable damage from downed trees and debris. The fallen trees had damaged sections of the stair railing. One of the three guns had been moved off of its platform by the wind and needs to be reset.
Detailed Damage Description
The following detailed description of damage at each facility is based on the preliminary assessment field observations, follow-up site visits and discussions with the park staff.
Haloda Bldg.; Park HQ and Visitor Center:
Mechanical; Two (2) air cooled condensing units need replacement with panel covers blown away exposing electrical power and control systems, condenser fins are corroded beyond repair. Two downspouts from roof drains located in basement were severed near the floor that contributed to water flooding in the lower level garage. The air-handling unit inside the mechanical room appears to be functional but does not meet building code clearance requirements. At the ground floor toilet, one exhaust register is missing, water is dripping around exhaust duct. Dripping water is apparently from the second floor that had water accumulation during the typhoon.
Electrical; Remove and relocate building electrical service and distribution panels from existing lower level main feed. Basement is unsafe location for building power and stand-by generator due to storm surge and wave inundation. A cost for a new electrical building is included with the civil/structural works estimate.
Structural; One exterior column (NW corner) by driveway to basement is cracked above the first floor beam connection. This crack is entirely through the column and is visible from the building's front and back. The crack does not appear to be serious or affect the structural integrity of the concrete frame at that location. Repairs may consist of applying an injected epoxy grout to seal the crack. However, there may be a future problem with this condition because salt air can penetrate and start corrosion in the reinforcing steel that will develop into concrete spalling on the column as the rebar rusts and expands.
In basement/parking level there are many concrete spalls in walls since rusted rebar has insufficient concrete cover. On the same level, column edges have rusted angle iron on all four corners. A non-bearing concrete block wall (approx.7ft. high and 20 ft. long), protecting electrical service panels, was knocked over from the wave surge into basement/parking level.
Civil; The lower level/basement drainage system is inadequate, clogged with sand and undersized for the stormwater flow entering the basement parking level. Adjacent asphalt parking lot (60 ft. x 160 ft.) is completely destroyed by wave action up to entrance and exit driveways connected with the main roadway, Route 1.
If the decision is made to restore and reoccupy the Haloda Building, then a shore protection structure (approx. 200 to 250 feet long) should be constructed. This seawall should prevent damage from minor storms to the parking lot and basement level. However, damage may still occur from waves generated by super-typhoons similar in magnitude to Pongsona.
Architectural; Canopy above roof access door damaged. Exterior canopy on ground floor at ocean side lanai damaged. Broken exterior ceiling/soffit at basement level, at ground floor, and above second floor windows. Interior water damage such as wet carpet, water trapped above ceiling, inside light fixtures and file cabinets. Corrosion is apparent on metal surfaces from salt water spray during typhoon. Mold and fungus is growing on interior surfaces, especially ceiling and lower walls; wet and smelly carpet from mildew. There were many broken or damaged doors and windows, both exterior and interior, due to wind pressure and water. Debris on exterior building surfaces, paint peeling and bubbling.
Asan Maintenance Complex:
Mechanical; Three (3) roof ventilators were blown away or damaged and will require replacement. The building's air conditioning system (4 ton unit) was inspected by Carrier, on Jan. 02, 2003 and they recommend replacement of the compressor and voltage monitor. Trailer office moved by wind with damage to plumbing waste and water piping.
Electrical; Main building ceiling fluorescent light fixtures had water intrusion, need to clean, dry out and test system. Fuel equipment room electrical ventilator system is non-operational. The electrical post with meter was blown down cracking the PVC conduit. Trailer office moved with damage to weather head and electrical supply panel, needs replacement (220 volt, single phase). The building's security alarm system is inoperable.
Structural; Damage to main building covered under architectural, no serious structural damage observed. Office trailer blown off concrete block pedestals, this has been realigned but it needs a new foundation and tie-down system.
Civil; Straighten about 150 linear feet of 8 foot high chain link fence. Replace 15 foot long sliding gate damaged by wind, realign main sliding gate (15 ft.) Patch asphalt access road 20 ft. by 10 ft.
Architectural; Water leak through mortar joints of glass blocks. Minor damage to roll-up service doors (5 each). Broken roofing membrane, wet insulation boards, broken flashing and reglets. Wind blew in the exterior side door breaking the door handle locks and blew open the interior steel door also breaking the locks to the fuel equipment room. Wind uplifted a portion of woodframe and plywood mezzanine floor.
Asan Point Beach Unit:
Mechanical; No apparent damage to comfort station, but new (2 each, 4-inch grinder) pumps may be required for sewage lift station since they can freeze up after inundation by salt water.
Electrical; Exterior lights for flag poles (2 each) and 50th Marine Monument (6 each) destroyed by wave action and needs replacement (8 total with conduit and conductor cable). Structural; The stone veneer (marble) on the 50th Marine monument is stained, chipped and discolored. Bronze plaques on monument and placed in sidewalk need to be examined by conservator familiar with restoring this material after salt water damage. Monuments along beach-side are damaged and one is missing a plaque. Two metal flagpoles (25 ft. tall) need to be sanded and painted.
Civil; Entrance gate (metal square rods/tubes, 3ft. x 20ft. swing leafs) has one side broken off at hinges and second connection, needs to be repaired. Concrete bollards need repainting (400). Display bomb blown off concrete pedestal, reset. Concrete wheel stops thrown around lawn but not damaged, reset 50 each, after parking lot repaving. Park furniture damaged consists of 4 broken recycled plastic benches, 4 recycled plastic tables, 5-BBQ stands (steel fire box on round tube post), kids benches, slabs and signs (2'x 2', 2-each missing & 4'x 6', 2-each missing).
Concrete walk, 12 ft. wide by 30 ft. long, at Asan Point washed out by wave surge. Asphalt parking lot pavement (6,910 sy) destroyed by wave action. Asphalt walkway covered by sand and coral washed up onto the grass. This material came from embankment along the shoreline (at the edge of the sandy beach area) which is approximately 1,000 feet long, 10 feet wide and 4 feet deep, with a total volume of 1,480 cubic yards to be reinstated.
Coconut trees heavily damaged; approx. 20 percent or 200 with broken tops and will probably die; 10 were uprooted; about half (570) show salt spray/wind burn.
A rock revetment barrier for the inner reef flat (4ft. to 6ft. depths) consisting of a 10 foot wide "L" shaped jetty (200 feet) and breakwater (100 feet) that had been constructed by the US Navy was damaged by wave action. This man-made structure is a feature of the NHP invasion beach (3rd Marine Division) and is integral to the experience of returning war veterans and visitors to the park. The large (2-ton to 5-ton stone/rock) rip-rap has unraveled and should be reset to its original positions. Failure to complete this restoration will allow tidal action to cause major deterioration of the beach area the revetment is supposed to protect.
Architectural; No apparent damage to comfort station. However, the cost estimate for repairs at this location under this item will consist of cleaning and restoration for storm damage to the monuments and memorial plaques.
Apaca Point Beach Park:
Ga'an Point Beach Park:
Asan Point Overlook:
Cost Estimate of Repairs
The following cost estimates for repairs are delineated in two categories. That is they are separated by facility within the park and for each facility the costs are separated by discipline (architectural, civil/structural, electrical and mechanical). A summary of these estimates by facility consists of the following:
Cost Estimate Summary Table
Other costs associated with the storm damage, incurred directly by NPS consist of, but are not limited to the following; debris cleanup, packing, moving and storage, rental space, building security, miscellaneous damaged items, cleaning, testing, servicing, repair and/or replacement of equipment (this applies to shop equipment and electrical equipment), post typhoon increased communication costs, and additional labor. These costs are not quantified within the scope of this report. However, other costs associated with the Additional Observations are shown below:
#1) This price does not include preservation/restoration work on any part of the museum collection.
Note that these items are not all inclusive to the extent of improvements that could be made and/or may be contemplated by the National Park Service.
Restoration work on the Park monuments and conservator's work on the bronze plaques, memorial name lists and relief sculptures are not included. The detailed cost estimates, WAPA site map, and appendix with photos follow.
GCIC Bldg., 414 West Soledad Avenue, Suite 904, Agana, Guam 96910 USA