Temperature Effects of Point Sources, Riparian Shading, and Dam Operations on the Willamette River

Trading Tool

Cougar Dam: aerial view (Photo: US Army Corps of Engineers, 12-Jul-1989)

Trading heat allocations among point-source dischargers may be a more economical and efficient means of meeting the cumulative point-source temperature limits set by the TMDL. The cumulative nature of these limits, however, precludes simple one-to-one trades of heat from one point source to another; rather, a more detailed spatial analysis is needed.

In this investigation, the flow and temperature models that formed the basis of the Willamette temperature TMDL were used to determine a spatially indexed heating signature for each of the modeled point sources, and those signatures then were combined into a user-friendly, spreadsheet-based screening tool. The Willamette River Point-Source Heat-Trading Tool allows a user to increase or decrease the heating signature of each source and thereby evaluate the effects of a wide range of potential point-source heat trades. By simply selecting a target time period and modifying the strength factors associated with each point source in an iterative fashion, potential trades can be defined and the effects on the temperature of the river can be estimated.

The predictions of the Trading Tool were verified by running the Willamette flow and temperature models under four different hypothetical trading scenarios:

1. MWMC at 50%, Corvallis and Albany at 150% -- results
2. MWMC and Cottage Grove at 0%, Corvallis at 200%, and Albany at 300% -- results
3. Cottage Grove at 0%, Salem at 80%, and Newberg and Wilsonville at 200% -- results
4. Cottage Grove at 0%, Weyerhaeuser Springfield at 50%, and Weyerhaeuser Albany at 200% -- results

Results from these test cases are documented more fully in an available report. Typically, the predictions of the Trading Tool for these tests were accurate to within about 0.005 degrees Celsius. The Trading Tool may be downloaded from the following links:

	Simple version:	version 1.4a	[XLS, 12 Mb]
	Latest version:	version 1.5	[XLS, 15 Mb]
	"Professional" version:	version 1.5 pro	[XLS, 15 Mb]

Please note that the "professional" version is identical to version 1.5 but has one additional feature (two-site trade charts). Use of that feature should be avoided unless you have had specific instruction in how to use it properly.