WAILUKU - While the trade winds brought an unusual rainfall pattern to the islands in August, Maui County remained in drought conditions over the past week, with South Maui still classified in extreme drought.
Showers also have slowed, reducing flows out of the East Maui watershed. But consumers showed a higher level of restraint, cutting average water use over the past week by 480,000 gallons a day.
"The good news is that the Central Maui production demand slipped below 25 million gallons a day," Water Director Jeff Eng said in his weekly water use report.
The Central Maui water system serves the region that includes Paia, Wailuku-Kahului and Kihei-Makena, where demand had been running over the 25-mgd target Eng has set for the system. For the week of Aug. 28 to Sept. 3, average demand slid to 24.99 mgd.
The Board of Water supply is continuing a drought watch calling on consumers in Central and South Maui to reduce water use by 10 percent.
Upcountry consumers have been asked to cut use by 5 percent. For the week, average demand remained relatively high at 7.87 mgd. But the draw dipped to a low of 6.3 million gallons Friday.
"This past week, we saw only a trace of rain in most parts of the county. Fortunately, for Upcountry Maui, the intermittent showers in the East Maui watershed helped the department maintain its raw water storage levels," Eng said.
A slowdown in trade showers is expected to continue this week, according to the National Weather Service forecast. At the same time, Upcountry water flows were dropping. While Upcountry reservoir levels were still high at 140 million gallons Friday, the flow in the Wailoa Ditch - which is an indicator of the condition of the watershed - fell steadily from 99.6 mgd Aug. 31 to 50 mgd Friday.
The state forecast Saturday said trade winds are expected to weaken through the week, with an upper level low pressure system interfering with the surface high pressure ridge that generates the trades.
That is likely to cut into the trade showers on the watersheds, although a convective pattern that could result may bring showers to leeward slopes.
The upper level low is part of a frontal system moving across the North Pacific that may also generate an early season north shore surf break.
A rainfall report for August said nearly all of the state continued to record below-normal rainfall for this point in the year, although several rain gauges received well above normal rain for the month.
The report prepared by weather service senior hydrologist Kevin Kodama cited spikes in rainfall that occurred in East Maui areas, although the key watershed gauges remained below normal. Unusual showers were recorded particularly at Ulupalakua and on Kahoolawe.
The rainfall numbers for Kahoolawe were small, 1.52 inches at Honokanaia and 0.5 inches at Moaulanui. But those numbers were 217 percent and 250 percent of normal for August.
Across the Alalakeiki Channel at Ulupalakua, where the rain clouds normally form and stretch across to Kahoolawe, 3.85 inches fell in August, 296 percent of normal for the month.
"As is often the case, Maui County rain data exhibited the widest range of conditions in the state," Kodama said. "In South Maui alone, August percentages of normal values ranged from 15 percent at Kihei to 296 percent at Ulupalakua, just seven miles away.
"Upcountry Maui rainfall has been interesting this summer, with Ulupalakua sitting within a narrow wet belt along the southwest rift of Haleakala, surrounded by drought-stricken, desiccated pastureland."
He noted that Ulupalakua has recorded an unusual number of heavy rain days during the summer, with five days of an inch or more.
"In July and August, the Ulupalakua gauge recorded 10.10 inches of rain, which translated to 374 percent of normal, while the Kula gauge nine miles away recorded only 0.62 inches, or 39 percent of normal," Kodama said.
In the watersheds, though, the numbers were down. West Wailua Iki in the East Maui watershed recorded 15.53 inches in August, 79 percent of normal.
Puu Kukui in the West Maui watershed received 16.33 inches, 50 percent of normal for August. Considered the second-wettest spot in Hawaii, Puu Kukui is at 54 percent of normal for the year, with 143.83 inches.
The wettest place in Hawaii at Waialeale on Kauai is at 76 percent of normal, with 216.52 inches for the year.
* Edwin Tanji can be reached at citydesk@mauinews.com.
