Managing stormwater on Powell Butte
The return of the rainy season reminds us that Johnson Creek, which runs through southeast Portland, has a history of flooding. That is one of the reasons that stormwater management is a top priority and a critical component of the Powell Butte 2 Reservoir project. The stormwater management methods employed on the butte are designed and built to accommodate rainfall amounts that could result from a 100-year rain event - the amount of precipitation that could be equaled or exceeded every 100 years, on average. Photo above: One of two temporary stormwater holding ponds collect and detain rainfall before the water is slowly discharged to Johnson Creek.