The river is expected to crest at about the 16-foot mark about noon today.
Some road flooding can be expected today.
Heavy rain over the north Cascades today and tonight could result in a significant rise in the river level.
Drivers are advised to avoid the area for a while.
A collision on I-5 is reported to have brought down the power lines.
The deceased's name was withheld until family could be notified.
WSP: Alcohol and/or drugs are considered contributing factors in the crash.
The woman was reported to have been struck by a red or orange 4-door passenger car, possibly a Chrysler 300 or a Dodge Charger.
Work to set a 30-foot pipe in place has been completed.