Columbia Slough Watershed Facts

The Columbia Slough watershed contains:* 32,700 acres* Largest urban wetland in the USA (Smith and Bybee Lakes Wildlife Area )* Salmon refuge in the Lower Slough* 175 bird species* 26 fish species* 6 lakes, 3 ponds, 50 miles of waterway* 30 miles of flood control levees* 158,000 residents (1/20 of Oregon's population)* 54 schools, 2 universities, 1 community college* Critical wildlife corridors

From: Columbia Slough Watershed Council

* Portland International Airport* Port of Portland marine terminals* 3,900 businesses* 57,000 jobs* 54% impervious surface* Columbia South Shore Well Field (drinking water)* One of Portland's "industrial sanctuaries"* Critical transportation corridors (I-5, I-205, I-84)* 250,000 railroad cars per year use its railroad tracks* The Slough is 303(d) water quality listed* 6 Golf Courses* 40 Mile Loop Trail* Canoe and kayak launches* 426 acres without sewers* Whitaker Ponds Environmental Learning Center* Lewis and Clark expedition sites* Historic Native American settlement sites

PSU/OGI Model of PCB & Chlordane Behavior in Buffalo Slough

In 1998 TMDLs were established for the Columbia Slough for pH, dissolved oxygen, phosphorus, chlorophyll-a, bacteria, lead, DDE/DDT, PCBs, dieldrin, and 2,3,7,8-TCDD.

Total Maximum Daily Loads303 (d) Requirement