By Sarah Taylor, co-founder and board member of Braided River Campaign. Share your comments and questions with Sarah at sarahsojourner@mac.com.

Quick Lesson #1

What is the North Reach of the Willamette River?

The North Reach refers to the last nine miles of the Willamette River from the Broadway Bridge to where the Willamette River meets the Columbia River at Kelly Point Park. Portland divided its part of the Willamette River into three sections; the south, central and north reach.   These terms were created as part of the state mandated Greenway Plan for every area that borders the Willamette River.

What is the Lower Willamette River?

The area from Willamette Falls to the confluence with the Columbia River is known as the Lower Willamette.   This part of the river is tidal and flows through Portland.  The tidal changes can cause the river to change its depth and even change the direction it flows.  A very low tide can cause the river to change direction and flow south. 

What Portland city council districts are impacted by decisions in the North Reach?

Every city council district in Portland borders the Willamette or Columbia Rivers, the Columbia Sloug,h or creeks that are tributaries of the Willamette River.  District 2 and 4 are directly part of the North Reach

Quick Lesson #2

Where is Portland’s North Peninsula?

North Portland is composed of two rivers, the Willamette and the Columbia, that meet to create a peninsula.   The land between the two rivers and the mountains, to the west, create a unique landscape that best describes the Northern reaches of our city.  

Why is Portland’s North Peninsula a special place ?

The peninsula was traditionally a place abundantly interwoven with lakes, streams, sloughs, and wetlands; rich in wildlife, fish and forests.  It served as a place of villages; a transportation corridor and meeting place for tribes along the Columbia and Willamette Rivers since time immemorial.   

Quick Lesson #3

How was the North Reach and the Peninsula formed?  Why can geology inform our decision making in the North Reach? 

The Willamette River and the surrounding lands were formed by millions of years of volcanic activity accompanied by shifting plate tectonics, ice ages and melting glaciers. 

About 15,000 years ago, the Missoula Floods swept through a valley creating a vast braided river system which we now know as the Willamette River.  Layers of sediment and rock were deposited on the banks.   This created the fertile soils that make the Willamette Valley a welcoming place for plants and farming.  It also means that the land we build on is rarely bedrock.  

The same systems of shifting plate tectonics continue to exist and create fault lines beneath the city.   The larger Cascadia Subduction Zone (CSZ) Fault Line runs along the west coast of North America and is predicted to lead to large earthquakes in the future.  Soil along the Willamette River will “Liquify” and slip into the river.  Geologists predict that the structures built on liquifiable soil will slip into the river including the liquid fuel tanks.  

Quick Lesson #4

The Willamette River was a Braided River

Rivers can be described by the shape of their channel.  Examples include meandering, braided, straight and anastomosing.   Our city’s river was a braided river.

A Braided River has islands (Like Swan Island, Ross Island and Sauvie’s Island) and many off channel lakes and streams.  (Like the former Guilds Lake and Smith and Bybee Lakes) 

A braided river weaves around  islands and streams.  It floods and the North Reach has  both low and high tides.  A braided river has bars and a meandering system of smaller channels.  

The braided North Reach, provided a sustainable economy for tens of thousands of years.  When European settlers arrived, they sought to channelize the river; by eliminating many of the lakes and islands.  The river was dredged and the dredge became the liquifiable soil we now find on the riverbanks.  The banks were hardened and the once abundant salmon population shrunk to less than 1% of the juvenile salmon that existed in the braided river system.

Knowing the original shape of the North Reach, helps us to understand the challenges and potential of this part of the city.