The Virginia Flood of 1969
Total Page:16
File Type:pdf, Size:1020Kb
DEPARTMENT OF CONSERVATION AND ECONOMIC DEVELOPMENT l . t/( Jo..., DIVISION OF WATER RESOURCES I RICHMOND, VIRGINIA INFORMATION BULLETIN 505 1911 THE VIRGINIA FLOOD OF 1969 the effects of Hurricane Camille in the James River Basin of Virginia UNITED STATES GB 1225 .V8 K3 PARTMENT OF THE INTERIOR GEOLOGICAL SURVEY ~ .... ... .. - ... d .... .. ... ··~.-.. ~ .. __ . ... .. _ , Q3 I CJ,;J $' \fb ~<3 UNITED STATES DEPARTMENT OF INTERIOR GEOLOGICAL SURVEY WATER RESOURCES DIVISION THE VIRGINIA FLOOD OF 1969 the effect$ of Hurricane Camille in the James River Basin of Virginia By Donovan Kelly I; DEPARTMENT OF CONSERVATION AND ECONOMIC DEVELOPMENT v~. DIVISION OF WATER RESOURCES RICHMOND, VIRGINIA INFORMATION BULLETIN 505 1971 THE VIRGINIA FLOOD OF 1969 The Effects of Hurricane Camille in the James River Basin of Virginia by Donovan B. Kelly INTRODUCTION At one point the rains fell at a rate and volume not likely to be equaled or exceeded in the stricken area Tuesday, August 19 began as a quiet Election Day in more than once in a 1 ,QOO-years or more. Hurricane Virginia and ended as the night of the flood of '69-in Camille was the prime cause of the rains but not the sole deaths and dollars, probably the greate~t natural disaster cause. in the history of the State. In the wake of a 1 ,000-year As the election polls closed on that Tuesday, August rain, a 100-year flood, and landslides that reshaped 19, Camille was a tropical depression (an area of low slopes and valleys along a 40-square mile stretch of the pressure, moderate winds, and moderate precipitation) Blue Ridge, 152 Virginians were dead or missing, centered somewhere in eastern Kentucky. Two days including 1 percent of the population of Nelson County, earlier, Camille had been one of the most violent hardest hit part of the State. The bill to repair the hurricanes recorded on the U.S. mainland, but after damaged land, buildings, and highways of Virginia totals leaving Mississippi she lost much of her fury; over more than $116 million and much of the farmland may eastern Kentucky she produced only about 2 to 4 inches never be reclaimed from the mud and boulders. of rain and her winds continued to decline as she This report is a description of the rain, water, and marched east toward Richmond and the Virginia coast mud that flooded and gutted the James River basin (fig. 1 shows the path of Camille). There was no reason during and after the passage of Hurricane Camille. to change the precipitation forecast on Tuesday as Through words, numbers, and pictures, the report Camille moved into West Virginia and Virginia. summarizes the impact of the Virginia flood of '69. Earlier that day, during the height of the afternoon rush hour traffic, the Weather Bureau alerted the ACKNOWLEDGEMENTS Washington, D.C., metropolitan area to possible flash flooding from another storm system. Fortunately for the The facts, figures, photographs, and quotations used Washington commuters, the thunderstorms that might in this report were supplied by the residents, reporters, have caused flooding slipped south, towards the James and local, State, and Federal workers while they were River, without dropping any of their water load. still in the midst of putting the James River basin back together again. Their aid and patience in helping with this report are gratefully acknowledged. Most of these people and organizations have been named and cited in the text and beneath the photographs. In addition I would like to thank the Civil Defense Office in· Richmond and the U.S. Soil Conservation Service for their aid, as well as the members of the Virginia Division of Water Resources who joined U.S. Geological Survey fieldmen from Virginia, Pennsylvania, Maryland, West Virginia, Delaware, South Carolina, and Illinois in recording the physical dimensions of the flood. THE RAIN MILlS The drenching rains that fell on the slopes and valleys 0 100200J00400S00600700 of the Blue Ridge Mountains in Virginia resulted from the unfortunate combination of several weather factors. F I G• THE PATH OF HURRICANE CAMILLE 1 The James River lies IOO to 200 miles south and than three times the State's previous record of 8.4 inches southwest of Washington and its basin stretches across in 12 hours and aP,proaches the all-time rainfall records Virginia from west to east, from the Blue Ridge in the United States. Just as significant to the Mountain town of Covington to the ocean port of flashflooding, the heavy rains were extensive throughout Norfolk. Of all the river basins in southern Virginia, the the basin. In fact, rainfall in excess of 4 inches fell over IO,OOO square-mile basin of the James River is best an area 30 to 40 miles wide and more than 130 miles oriented to collect the maximum water from large long as the storm moved eastward across Virginia. storms moving southeast or east across the State. "The combination of weather factors near the area of heaviest rainfall-the presence of wet maritime air, the southward movement of thunderstorms and a cold front OHIO from the north, the arrival of Camille from the west, and the existence of narrowing valleys to concentrate and finally lift any northwestward-moving airmass-is even more unlikely than the 1 ,000-year rain that fell." One other factor was added to the string of weather events to make the flood of '69 the most destructive in Virginia's history: The 1 ,000-year rain fell in the middle of the night over the isolated homes and small towns in the valleys and hollows of the Blue Ridge Mountains. As one official from Nelson County told at a U.S. Senate 0 11:1 100 ~--~ hearing a month after the flood: "The rains fell at the worst possible time, 3 to 4 a.m. in the morning. Even if FIG. 2 JAMES RIVER BASIN OF VIRGINIA we had some warning of the coming flood, there was no way we could have. gotten word to our people. Even before the arrival of Camille, a concentrated Everybody was in bed with radios and televisions turned mass of moist maritime-tropical air already hung over off, and the mud and water came too fast for neighbors the headwaters of the James River basin. In the early to warn one another." evening this wet air mass began to increase its moisture content, especially at high elevations, by feeding on He reported that Nelson County lost about I percent early arriving remnants of Hurricane Camille. The of its citizens: "Out of a population of I2 ,500 people in moisture content in the air mass soon approached the the County, 88 are dead, and 39 are still missing and maximum possible level for the time, place, and season. presumed dead." Camille not only added moisture to the air over the James River basin but also concentrated some of the THE FLOOD moisture over Nelson County by changing the wind direction. As Camille marched east, her winds continued to move counterclockwise around the center of the The torrential rain produced streamflow equal to at decaying hurricane, drawing moisture from the Atlantic least a record-breaking IOO-yea~ flood throughout much Ocean and spinning off wet air masses to the northwest. of the upper basin as far east as Richmond. (A IOO-year When the center passed over the West Virginia border flood is one so great that it is not likely to be equaled or into the Virginia headwaters of the James River, some of exceeded on the average of more than once every I 00 this moist spinoff was pushed up the narrowing valleys years. Thus the flow of 225,000 cubic feet per second in of the Rockfish and Tye Rivers. As these additional the James River near Richmond on August 22 will masses of wet air moved up the valleys, they were probably not be equaled or exceeded more than ten compressed by the ste.ep ridges on either side and finally times every I ,000 years, although such a flood could forced to rise up the hollows near the V-ends of the occur again tomorrow.) Flooding with a IOO-year or valleys. The results of the compression and forced rising greater recurrence interval was general throughout most was to further increase the local precipitation. of the basin west of Richmond. Most of the sites where According to a Weather Bureau spokesman, "The devil hydrologists from the U.S. Geological Survey or the himself couldn't have put together a more unlikely series Virginia Division of Water Resources computed flood of freakish events with such perfect timing to produce measurements are shown in figure 4 and the peak flows such a concentrated torrential rainfall. The maximum are listed and compared with those of floods of previous verified amount of rain reported, 27 inches, is close to years in table I at the end of this report. Details on these the maximum amount of rainfall theoretically possible flows have been published in several U.S. Geological in this part of the world in an 8-hour period. It is more Survey technical reports. 2 i 0 0 0 0 ...J LL. LJJ ...J ...J ~ u LJJ :z: <x: u a: a: :::> :t: 'LJJ :t: 1- c..!l :z: a: :::> 0 0 LJJ Vl :::> Vl :z: 0 ~ 1- Vl Cl :z: Cl <x: Cl u :z: a: a.. LL. 3 Flood flow measu rements are made to help predict more common flood s, say the one that can be expected how often flood s of a certain magnitude can be expected about once every 5 years , because people are familiar in the future.