In late July and early August 2008, several floods affected several rivers in the central portion of the American state of Alaska. The city of Fairbanks, Alaska saw high water levels, while the towns of Nenana, Salcha, and Old Minto received heavy damage. The Salcha River and Tanana River reached their second-highest levels since record-keeping began (the highest was during the 1967 Tanana Valley Flood), while the Chena River, which bisects Fairbanks, was kept below flood stage by the use of the Chena River Lakes Flood Control Project.
Several hundred homes were inundated by the flood in Fairbanks, Salcha, unincorporated Fairbanks North Star Borough, Nenana, and smaller villages, but due to early warnings from the National Weather Service, volunteer fire departments, and the borough's emergency contact system, no one was injured. The area affected by the flood was declared a state disaster area, making residents whose homes were flooded eligible for state aid. The long-term effects of the flood, including its effect on the salmon spawning season, are as yet unknown.
Background
The summer of 2008 was an unusually wet one for central Alaska. In June, the National Weather Service recorded of precipitation at the Fairbanks International Airport—the most in that month since June 1994, and above average.Shulski, Martha. "June was a cool, wet month for most Alaskans," Fairbanks Daily News-Miner. July 20, 2008. Accessed August 2, 2008. By July 27, 1.47 inches of rain had fallen in July. This was slightly below the average for the month at that time (1.49 inches), but the year-to-date rainfall total was still one and two-thirds inches above normal.National Weather Service Observed Climate Reports: July 27. The National Weather Service, Accessed August 2, 2008. The next day, July 28, 1.14 inches of rain fell in Fairbanks, setting a single-day Fairbanks rainfall total for that date,National Weather Service Observed Climate Reports: July 28. The National Weather Service, Accessed August 2, 2008. with heavier amounts measured east of the town. Scattered locations between Salcha and Delta Junction received up to four inches of precipitation. On the 29th, another 0.77 inches of rain fell in Fairbanks—another record for the date—and again, locations outside of the town received greater amounts.National Weather Service Observed Climate Reports: July 29. The National Weather Service, Accessed August 2, 2008. Just 0.14 inches of rain fell on the 30th, but on the 31st, 0.6 inches fell. This amount was not a record for the date, but it brought the overall rainfall total in Fairbanks for the month of July to 4.12 inches—more than double the normal average of of rain.National Weather Service Observed Climate Reports: July 31. The National Weather Service, Accessed August 2, 2008. At Eielson Air Force Base, which lies to the southwest of Fairbanks, 7.30 inches of rain were recorded as having fallen in July, making it the rainiest July ever recorded and the second-rainiest month ever recorded at the base. Though more rain fell on August 1 and afterward,Alaska Climate: August 2008 The National Weather Service, Fairbanks, Alaska. Accessed August 3, 2008. the Tanana, Salcha, and Chena rivers had already crested.See graph.
Flood Salcha
By the evening of July 28, the record-breaking rainfall that had fallen to that point caused the National Weather Service to issue a flood warning for the tributaries of the Tanana River east of Fairbanks.Smetzer, Mary Beth. "Tanana River under Flood Warning", Fairbanks Daily News-Miner. July 28, 2008. Accessed August 3, 2008. On the 29th, the continued rain forced the expansion of the flood warning to cover the entire Tanana and Salcha River basins between Salcha and Nenana, a stretch of land long.Staff Report. "Flooding in Interior Alaska area spurs voluntary evacuations", Fairbanks Daily News Miner. July 29, 2008. Accessed August 4, 2008. The rising Salcha River forced home evacuations on the 29th and caused the Old Richardson Highway to be closed in several locations as the Salcha overflowed its banks and covered the road near the town of Salcha. An emergency shelter was set up to handle refugees from the Salcha River's flooding, and forecasters predicted the river would continue to rise.
On the 30th, the Salcha River crested at 16.8 feet—almost three feet above flood stage—where it crosses the Richardson Highway.See graph This was the sixth-highest crest since measurements began in the first half of the 20th century. The last time the river reached that height was October 15, 2000, when the river crested at .Historical Crests for Salcha River at Richardson Highway Bridge The National Weather Service, Accessed August 4, 2008. More than 100 homes were at least partially underwater, and nearly two dozen Salcha town residents took advantage of the emergency shelter that had been set up at Salcha Elementary School the day before.Staff Report. "Corps to divert bulging Chena to flood project" , Fairbanks Daily News Miner. July 30, 2008. Accessed August 4, 2008.
High water remained in Salcha through the 31st, though the crest of the flooding had passed.Bohman, Amanda and Eshleman, Christopher. "Tanana, Salcha rivers flood Interior Alaska ", Fairbanks Daily News-Miner. July 31, 2008. Accessed August 4, 2008. Water continued to cover roads in and around Salcha, and water-borne debris accumulated under several local bridges, causing impromptu dams. By August 1, the Salcha River had begun to recede to a noticeable extent. Though some roads remained underwater and falling trees knocked out power to areas of the town, residents began to pump out basements and begin recovery efforts.Eshleman, Christopher. "Tanana River crests in Fairbanks; Chena expected to crest Saturday ", Fairbanks Daily News Miner. August 1, 2008. Accessed August 4, 2008. By early afternoon on the first, the Old Richardson Highway had been cleared of water and the National Weather Service canceled its flood warning for the Salcha area.Staff Report. "Fairbanks North Star Borough issues disaster declaration", Fairbanks Daily News Miner. August 1, 2008. Accessed August 4, 2008.
Fairbanks The first effects of the flood began to be felt in Fairbanks late on the 29th, as the Tanana River overflowed its banks and covered low-lying areas of South Fairbanks. Thought was given on that date to closing the floodgates of the Moose Creek Dam, located on the Chena River as part of the Chena River Lakes Flood Control Project, but the Chena's rise was not as rapid as that of the Tanana, which lies to the south of the town, and no action was taken on the 29th. Engineers also considered lowering the gates on the 30th, but the flow of the Chena River had not reached a level where computer models mandated the closing of the gates to protect Fairbanks.
The Tanana River, which is not controlled by the flood project, meanwhile reached a crest of 26.60 feet at Fairbanks on the 30th.See chart. This amount was more than two feet above flood stage and was the highest level seen since August 1967, when the river crested at during the great 1967 Fairbanks flood.Historical crests for the Tanana River at Fairbanks National Weather Service, Accessed August 4, 2008. The height of the water caused flooding in the Rosie Creek and Chena Pump neighborhoods west of Fairbanks, and caused some residents to evacuate. Residents who remained were placed under a boil-water order for fear that floodwater had contaminated the public drinking water system. In response to the continuing spread of the flood, Fairbanks and Fairbanks North Star Borough authorities opened an emergency operations center to handle the response to the flood and answer residents' questions. Residents of the Rosie Creek neighborhood were awakened in the early morning hours of the 31st by borough warnings and volunteer firefighters, who instructed them to evacuate. High water had surrounded the residents' homes, causing many to flee to a shelter set up at a nearby elementary school. No residents were injured in the evacuation, something many of them credited to prompt and efficient warnings.Smetzer, Mary Beth. "Chena-Goldstream firehouse draws a crowd of evacuees, residents for emergency meeting ", Fairbanks Daily News Miner, August 1, 2008. Accessed August 4, 2008. The continued high water of the Tanana River caused overflow to flood into the nearby Chena, normally a tributary of the Tanana. Despite that unusual flow, engineers at the Chena River Lakes Flood Control Project decided not to close the project's floodgates, forecasting that the Chena would not rise above flood stage, even with the increased flow.
By the morning of August 1, the Tanana River had begun to fall in Fairbanks, just as the Salcha River had begun to recede in Salcha. Though isolated roads continued to wash out from heavy water flow and residents were not allowed to return to their homes, the water level of the river continued to fall. Due to this fact, the opening of Fairbanks' Tanana Valley Fair—scheduled for August 1—was not delayed.Smetzer, Mary Beth. "Fair preparations not dampened by rain", Fairbanks Daily News Miner. August 1, 2008. Accessed August 4, 2008. Despite the falling water level in the Tanana, the Chena River continued to rise due to the differing water levels in the two rivers. This fact caused the U.S. Army Corps of Engineers to close the floodgates of the Chena River Lakes Flood Control Project at 3:30 a.m. on August 1.Freiberg, Chris. "No quick relief from floodwaters in Interior Alaska: more rain on the way ", Fairbanks Daily News Miner. August 1, 2008. Accessed August 4, 2008. They remained closed throughout the day before being reopened at 5:30 a.m. on August 2.Bohman, Amanda. "State officials tour flood damage; water still rising in some areas ", Fairbanks Daily News Miner. August 2, 2008. Accessed August 4, 2008.
Nenana Though Nenana also received heavy rain from the storm system that began the flood, its position further downstream on the Tanana River meant that it did not receive the first effects of the flood until the 30th, when Alaska Railroad officials suspended operations south of Nenana due to track damage caused by rising water.
On July 31, the Tanana River began to overflow its banks in Nenana. Water flooded the rails of the Alaska Railroad in town, caused an evacuation of the town's clinic, and flooded low-lying areas throughout the town. By August 1, the entire town was at least partially flooded, with most basements and other low-lying areas being completely filled by floodwater. The flooding of the Alaska Railroad track in town forced a halt to all passenger and freight operations between Anchorage and Fairbanks, effectively cutting off Fairbanks from rail traffic.