Okinawa water levels fall, raising concerns
NAHA, Okinawa — A fairly dry fall has Okinawa officials considering whether to start water conservation measures in January.
An Okinawa Drought Countermeasures Council committee met here Monday to discuss what its members termed a startling drop in level in island water reservoirs. As of Dec. 20, Okinawa’s 10 reservoirs were on average at just 56.8 percent of capacity.
“If this trend continues, by January we may have to face to the situation where we were in 2004,” said Keiji Tamura, Drought Countermeasure Council chairman.
In 2004, after an unusually dry winter, voluntary water rationing took effect for all U.S. military bases on the island. The Okinawa water council decided to turn off the entire island’s water taps for eight hours nightly beginning March 29. Only a heavy rain the preceding weekend, which dumped 4.52 inches, on the island, canceled the mandatory shut-off.
Before the voluntary rationing ended, military bases placed restrictions on washing cars, watering lawns and gardens, and washing clothes, and issued a list of recommended conservation measures. The plan to shut off water taps overnight also prompted warnings against drinking tap water due to concerns related to loss of pressure in storage tanks for treated water. After seasonal storms and a passing typhoon drenched the island with 17 inches of rain over two weeks, rationing was rescinded on military bases June 14.
Water rationing on Okinawa previously was imposed in January 1994. The taps were turned off eight hours per night for 28 days.
The standing committee Monday agreed to decide at its next meeting in mid-January whether to start a water conservation campaign. The first step would be to advise islanders to restrict water usage voluntarily.
The early 2006 weather forecast is not favorable, said council member Hisao Uezu, of the Okinawa Meteorological Observatory.
“Precipitation for January will be either at average levels or less and the following three months is expected to be average,” Uezu said.
The dry spell began in August with rainfall at just 52 percent of the usual average for that month, according to data released at the meeting. September was dryer, with rainfall at just 31 percent of the usual average.
Rainfall in October reached 61 percent of average and in November reached 63 percent of average, but the average for the first half of December was just 39 percent of the usual.
The figures may come as a surprise to some people living on Okinawa who remember 2005 as an extraordinarily wet year, perhaps because the spring’s rainy season dumped plenty of rain on the island. In June, the island was drenched with 311.3 percent of the usual monthly average.
Tamura said Okinawa might be in better shape for a dry year because its second largest and 10th dam was completed. Haneji Dam, with 15.6 million cubic meters of capacity, began to store water in April. That brought the total capacity of Okinawa’s reservoirs to 90.45 million cubic meters.
“Had it not been for that addition, we would have long ago gone into water restrictions,” he said.
The 10 reservoirs were filled June 18, a situation that lasted just 10 days, said Yasuyuki Sato, of the Okinawa General Bureau’s River Management office.
He said Chatan’s seawater desalination plant also helped stave off conservation measures by operating at full capacity since Nov. 8, producing about 10.5 million gallons of purified water each day.
“With all these efforts, we are now somehow able to avoid water restriction," he said.