About 90 percent of all power lines on the island were downed by the storm, two of three desalination units were out of service, one 10-million-gallon water storage tank was destroyed and another severely damaged, and the sewage treatment system was out of service. A USGS employee, Bruce Green, living and working in St. Croix, played a key role in establishing emergency water supplies (see box, p. 8).

Damage in the U.S. Virgin Islands from Hurricane Hugo is estimated to total about $2 billion. The official death toll for this storm is 14.

Puerto Rico.- Rainfall associated with Hurricane Hugo exceeded 10 inches in 48 hours near the town of Naguabo in eastern Puerto Rico. Total rainfall, however, was between 4 and 8 inches over much of the east. The amount and intensity of rainfall were substantially less than those associated with other large hurricanes. Inland flooding, however, did occur along some small streams. Storm-tide elevations along the eastern and northern coasts of Puerto Rico ranged between 4 and 10 feet but exceeded 12 feet near San Juan. Coastal flooding occurred in some beach and low-lying areas.

The Luquillo Experimental Forest, also known as the Caribbean National Forest, was severely damaged. The area in and around the forest, where rainfall amounts and intensities were high, was also the site of more than 200 mostly shallow landslides on the steep and highly dissected mountain slopes. Half of the landslides were associated with highway construction and road cuts.

Other damage from the hurricane included the loss of fish and shellfish from lagoons along the coast as a result of drastic changes in water quality associated with the storm. Within several weeks after the hurricane, USGS teams sampled and tested the water quality of Laguna de Piñones, Laguna La Torrecellia, and Laguna San Jose. The most significant changes in water quality were noted in Laguna de Piñones where dissolved solids concentrations, which normally range from 14,000 to 32,000 milligrams per liter, had been reduced to 2,600 milligrams per liter by the freshwater flowing into the lagoon as a result of the heavy rains. Dissolvedoxygen concentrations, which normally exceed 6 milligrams per liter, were less than 3 milligrams per liter, and concentrations of sulfide, normally less than 0.5 milligram per liter, had increased to more than 10 milligrams per liter.

Property damage in Puerto Rico is estimated to be about $2.5 billion. Only two deaths were directly attributed to the hurricane, but six employees of the power authority

were killed while repairing downed power lines.

of

South Carolina.- Rainfall produced by Hugo over the State of South Carolina ranged from a maximum of 10 inches south of Charleston to 2 inches in the upland part the State; more than 4 inches occurred only in the southern coastal area. Rainfall from Hugo was much less than expected, and no serious flooding of inland rivers occurred. Severe coastal flooding occurred along much of the South Carolina coast. The high-water elevation at the Charleston tide gage peaked at about 10 feet above sea level shortly before 1:00 a.m. on September 22 when the hurricane came ashore. This peak was about 8 feet higher than the normal (predicted) tide stage.

Water-surface elevations related to the storm surge were even higher in other areas along the South Carolina coast. Water-surface elevations of 12 to 16 feet above sea level were common in much of the area from Myrtle Beach southward to Sullivans Island east-northeast of Charleston. High-water elevations, based on more than 300 flood marks, were located and surveyed by USGS personnel within a few weeks after the storm.

The maximum water-surface elevations associated with the storm occurred in Bull Bay. The absence of barrier islands and the trapping effect of the bay on waves driven by extremely high onshore winds resulted in peak water-surface elevations of about 20 feet above sea level. Very few storms have ever produced storm surges of this magnitude along the East Coast of the United States (see "Hurricane Hugo and the South Carolina Coast," p. 11).

Damage to property along the South Carolina coast was severe and is estimated to be about $5.9 billion; 29 deaths have been attributed directly or indirectly to the storm.

Hurricane Hugo was one of the most destructive storms to hit the Caribbean and East Coast of the United States during this century. The devastating effects from Hugo underscore the need to continue efforts to study and understand the mechanisms and potential effects of hurricanes and other coastal storms. By being prepared as best as possible for nature's capricious action, we can help to reduce a disaster's toll.

Hurricane Hugo and Puerto Rico

By Rafael W. Rodriguez and Richard M.T. Webb

oastal resources as diverse as offshore

recreational beaches, and

coral reefs were affected severely when Hurricane Hugo struck Puerto Rico. The Puerto Rico Marine Geology Program, a cooperative study between the Puerto Rico Department of Natural Resources and the USGS, assessed the impact of the storm and monitored the recovery of these resources in the months following the storm.

Offshore sand deposits are of major importance to Puerto Rico because onshore sources suitable for use in the construction industry and in beach replenishment projects have been depleted. Escollo de Arenas, the largest offshore sand deposit (more than 3 billion cubic feet), was severely degraded by Hugo. The Escollo de Arenas is a trailing edge sand deposit, which lies off the northwest coast of Vieques Island. Soil cores and aerial photography show a loss of between 3.5 and 7 million cubic feet of sand from this deposit. The sand from the Escollo de Arenas

By Sandra L. Holmes

During the late evening and early morning hours of September 17-18, 1989, Hurricane Hugo, a category 4 storm, hit St. Croix in the U.S. Virgin Islands with sustained winds of 140 miles per hour and gusts of 200 miles per hour. Hugo battered St. Croix for 8 hours, damaged 90 percent of all homes and other buildings, destroyed the main power station, and cut off all sources of freshwater supplies to the island.

The USGS established a field office in December 1988 on St. Croix to support water-resources activities with the principal local cooperating agency, the Virgin Islands Water and Power Authority (VIWPA). Bruce K. Green, a USGS hydrologic technician stationed on St. Croix, had recently completed a project with the VIWPA in support of the siting and development of new public watersupply wells.

After cutting and clearing the way to the remote well fields, Green directed the construction of a temporary water-supply line to the disaster relief center. These efforts restored at least limited public water supply to island residents long before any other utility was available after the devastating storm. It took 5 months to repair the structure of and reinstall telephone and electrical lines to the U.S. Department of Agriculture building that had housed the USGS field office before the hurricane. During this time, Green operated the USGS field office out of the carport of his home.

For his dauntless courage and unquestioned leadership in an uncertain and potentially life-threatening situation, Green received the Valor Award of the U.S. Department of the Interior.

material is unrecoverable. At other sites, material lost from the beach margins was deposited in the nearshore zone.

Preliminary reconnaissance surveys show that about 10 percent of the stands of the shallow-water elkhorn coral in Vieques Passage were degraded considerably by Hugo. However, many deeper water coral colonies showed no visible impact. Hurricane Hugo left many Puerto Rican beaches, their valuable resources of sand, and their economic value as recreation sites more vulnerable to damage from future tropical storms.

Hurricane Hugo and the South Carolina Coast

By John W. Haines

ullivans Island and Isle of Palms, two of

South Carolina coastal area, were positioned to receive the major impact of Hurricane Hugo. The storm made landfall in South Carolina early on the morning of September 22, 1989. Historically, Sullivans Island and Isle of Palms have been remarkably stable coastal areas. By comparing the positions of past shorelines, coastal researchers can show that Sullivans Island and the southern twothirds of Isle of Palms have grown slowly seaward during the last 50 years. The effort of USGS coastal studies in the wake of Hurricane Hugo is focused on how the coastal effects of the storm relate to these long-term trends.

One of the special challenges of coastal research is that estimates of coastal erosion typically bracket periods of tens of years. Present shoreline positions are compared with past positions to determine the rate of coastal retreat or growth. These erosion estimates may or may not include the effects of a number of major storms, depending on how frequently an area has been affected by hurricanes or other coastal storms. Thus, best estimates of coastal land loss may mask the importance of these extreme, yet short-lived events. Coastal erosion in a particular area, therefore, may be due primarily to a few major storms, or it may reflect less extreme but more persistent processes. In addition, coastal response to hurricanes may depend on the presence of dunes and the width of the beach.

To gain a visual perspective on the coastal effects of Hurricane Hugo, the USGS and the National Ocean Survey made overflights of the South Carolina coast during the week of October 2, 1989. While aerial photography provides a means of rapidly accumulating data covering a wide area, the information