NAHA, Okinawa — A tropical storm passing to the west of Okinawa this week is expected to dump enough rain on the island to convince many islanders that the drought is over.
But the Okinawa Drought Countermeasures Council isn’t among them.
“We still need to wait and see before we can announce that we are out of the drought condition,” said Masaaki Mantoku, a member of the council and senior engineering officer for the Okinawa General Bureau, a national government agency that manages six of the island’s nine reservoirs.
“It would be more desirable if the recovery speed is much faster, but it is a tortoise-like pace.”
Weather forecasters at the Okinawa Meteorological Observatory anticipate considerable rain this week from Typhoon Conson, expected to pass directly over Taiwan, then weaken to tropical storm status as it wobbles toward the Chinese mainland.
“We expect a significant amount of rainfall through Thursday,” said Tadashi Zamami, weather forecaster at the observatory in Naha. “Rainy weather will dominate the island until June 23, when the rainy season is expected to end.”
He said total rainfall for May was 7.3 inches at Nago in northern Okinawa, where most of the island’s reservoirs are located. That was two inches less than average for the month.
A bit further north, in Higashi, the site of the major reservoirs, a total of 14.4 inches of rain fell — more than two inches above average.
And in the first week of June an additional two inches fell on Higashi, he said.
“Although the trend of smaller rains continues, the outlook looks pretty good in June,” Zamami said.
The Drought Countermeasures Council remains “cautiously optimistic” that enough rain will forestall imposing water rationing.
Okinawa has rested on the brink of water rationing since last February, when the reservoir levels dipped below 53 percent for the first time since 1987. At that time, all military bases on Okinawa imposed voluntary restrictions limiting car washing and lawn and garden watering.
Water levels continued to decrease to a rock-bottom point of 44.5 percent on March 27.
The island was scheduled to go into overnight rationing March 29, but a weekend deluge suspended the implementation.
However, even though the rains finally came, the island’s not quite wet enough for Okinawa officials to breathe a sigh of relief.
“After the rainy season is over, we have to expect almost no rainfall for the months of July and August until September, when the major typhoons usually occur,” Mantoku said. “Our water supply level drops almost 0.4 percent each day. So, based on that, our total water supply is estimated to drop by 18 to 20 percent during July and August.”
This means reservoirs must be at at least 70 percent full “before we can be assured we are out of drought conditions,” he said. When the reservoirs rise to that level, he said, “the Drought Countermeasure Council would discuss whether to announce an end to the drought."
On Tuesday, the level of water at the island’s reservoirs averaged 64.1 percent of capacity.
