During July, deep moisture streaming westward out of Canada caused flooding in sections of the Wrangell-St. Elias National Park. The village of Nabesna received heavy rain from July 22-25, this caused tributaries of Jack Creek to flood and wash out portions of the gravel road to Nebesna village. Three tourist groups were trapped for a few days and Park Service helicopters supplied them with food and water until the road was made passable again. The State estimates that it will cost $500,000 to repair these flood-damaged roads near the Alaska-Canada border and around Wrangell-St. Elias National Park.
A continuation of this moderate to heavy rain prompted a flash flood watch for the streams in the middle Copper River basin early on August 6th. Tributaries of the Copper River and the Chitina River experienced rising water levels and channel erosion but no problems were reported and the watch was canceled on the afternoon of August 6th. As a side note, this round of heavy rain was probably the catalyst in a glacial lake release on August 8th in the upper section of the Kennicott River, as a 4 foot rise was reported downstream in 24 hours, but no flooding was reported.
As the weather pattern changed, a river statement was issued August 8th for significant rises on rivers and streams in South Central Alaska. Several daily rainfall records were set during the period of August 8-13th. Because most areas in South Central Alaska were very dry and rivers and streams were running below normal, water levels rose sharply but only the two locations reviewed below required flood products.
The first was the Cordova area, a flood watch was issued for rivers and streams around Cordova and Eyak Lake on August 12th. Reports had been received of water in low lying areas near the outlet of Eyak Lake and several locations around town. By August 13th the high water from Eyak Lake covered the runway at the Eyak Lake Sea Plane Base, the adjacent road and had encroached upon some yards along the Eyak River. The high water also raised the ground water table, resulting in some seepage into basements. The flood watch was canceled later that day as the heavy rain ended and river and lake levels began to recede.
Some of this heavy precipitation also spilled over the coastal range into the already rain-soaked Copper River Basin prompting a flood watch to be issued on August 13th for the McCarthy Creek in McCarthy and areas along the McCarthy Road from Crystal Lake to McCarthy. McCarthy Creek was flowing about bankfull and washed out a footbridge. The creek came within 6 inches of flooding the old powerhouse in McCarthy. Along the McCarthy road from Crystal Lake to McCarthy, water came over the road at low spots where no culverts existed.
On the morning of August 14th the watch was upgraded to a warning for tributaries of the Copper River as heavy rain in the Chugach Mountains caused significant rises on all tributaries draining into the Copper River. The Tazlina, Klutina and other streams in the Western Copper River Basin crossing the Richardson Highway were reported to be flowing at extremely high levels and caused flooding in some areas. The Tazlina River rose substantially and flowed over a dike on the north side of the river designed to protect the bridge abutments. On the south side of the river, water had reached some driveways and was starting to affect homes. Minor flooding of a campground was reported on the Klutina River near the highway.
On the morning of August 15th the flood warning for the tributaries of the Copper River and particularly the Tazlina River was canceled due to falling water levels. It was noted that the Tazlina River rose due to a combination of 3 glacier lake releases and heavy rain in the Chugach Mountains. Three homes experienced some flooding and there was some erosion near the Richardson highway bridge.
A smaller scale event occurred on August 21st, where heavy rain spread across South Central Alaska, but was heaviest in the Anchorage Bowl. A flash flood warning was issued early on the 22nd for streams in the Matanuska Valley, Anchorage Bowl, and the Northern Kenai Peninsula. Many of the area streams were reported to be near bankfull, and some urban flooding was reported in the city of Anchorage. The warning was canceled later on the 22nd as water levels began to recede.
The last event occurred on the 31st of August as heavy rain once again spread across South Central Alaska, a suite of products was issued and rivers and streams were approaching bankfull late on the 31st. Early on the 31st flood and flash flood watches were issued for the streams in the Anchorage Bowl and Matanuska-Susitna Valleys, the Cordova and Eyak Lake areas, Lake Creek and Yentna River tributaries, the Little Susitna River, Willow Creek, Montana Creek and other streams draining the Talkeetna Mountains.
The flood watch for streams and rivers around Cordova and Eyak Lake was canceled on September 1st, heavy rain had caused the lake level to rise to high levels but no flooding was reported. The flood watch for the Yentna River and its tributaries was canceled on the 2nd, the Yentna River near the mouth of Lake Creek rose over 5 feet and Chelatna Lake rose over 1.5 feet. Lake Creek was reported to be at bankfull levels, but water levels were beginning to drop. The flood warning for the Little Susitna River, Willow Creek and Montana Creek was canceled on the 1st, Montana Creek and the Little Susitna River crested 2 feet below bankfull, Willow Creek crested just 0.3 feet below flood stage. No structures were flooded but some overbank flooding occurred. Another heavy rain fell along the North Gulf Coastal from the 6th to the 9th. A flood watch issued for the Resurrection River and other streams in the Seward area on the 8th, was upgraded to a flood warning on the morning of the 9th and canceled in the afternoon of the 9th. Storm rainfall totals of 3 to 6 inches caused minor flooding along Salmon Creek just north of Nash Road. The Resurrection River crested 0.5 feet below flood stage and upstream was within a few feet of the Exit Glacier Road. Some minor damage was sustained to the road below the Lowell Creek Diversion, bulldozer crews worked for three days straight to keep the water from washing away the bridge and cutting off a few hundred people who live on the road out to Lowell Point.
The last rain event of September was associated with a deep low that developed in the Gulf of Alaska and included remnants of typhoon David. Heavy rain fell over the mountains of the Kenai Peninsula from the 20th through the 25th. A flood watch was issued for the Turnagain Pass and Girdwood areas on the 22nd as heavy rain pushed stream levels to bankfull, it was canceled on the 25th. A flood watch was issued on the 24th for the Resurrection River and other streams in the Seward area, the Resurrection River crested 0.5 feet below flood stage, and similar minor flooding problems arose along Salmon Creek and at the Lowell Creek Diversion; the watch was canceled on the 25th. A river statement was issued for the Kenai River on the afternoon of the 25th informing the public that the Kenai River at Cooper Landing, Kenai Keys, and Soldotna would crest about a half a foot below flood stage at all three sites over the next three days. The Kenai River at Cooper Landing crested around 13 feet the morning of the 26th, about 1 foot below flood stage. The lake level was high enough to flood about 5 tent sites at the Quartz Creek Recreational Area, as well as flood certain sections of the road to the Primrose Campground Area. The Kenai River crested 0.5 feet below flood stage at Kenai Keys and crested almost 2 feet below flood stage at Soldotna on the 28th.