Lake Superior Tributary Models for Erosion and Sedimentation

I just sat through a webinar on some of the tributary erosion/sedimentation models developed by the Army Corps, Purdue and USDA to predict NPS runoff and sediment loads into Lake Superior. Did any of you get the notice on this? Most of the participants were from Carleton, St Louis and Cook Counties in MN and the UP.

Perhaps these tools are already in use by you all as resource professionals when you need to predict whether you get the most bang for your buck installing a practice in one site versus another on a stream. Some of the models are very specific like the model designed specifically for the Nemadji River (which lacks snow melt factors, is hard to use etc.). In Wisconsin, Army Corps is also in progress on a model for Whittlesey Creek, and scoping stage for Sisikiwit River and the St. Louis River. The Army Corps can only look at “federal harbor” sites, but that can include shallow-draft harbors. There are 91 tributaries in Lake Superior eligible for this modeling work. Obviously, their interest is reducing sediment to save $ on dredging harbors.

The Purdue model could be very useful with planning commissions, and even landowners. You can enter pre-development criteria about soils, area size and density of development, then chose a series of Limited Impact Development(LID) practices and compare the post-development runoff rates with or without LIDs. Purdue (Bernie Engel) hopes this model will help with TMDLs among other things.

One of the most interesting challenges is developing a forest-based model. Bill Elliot of USDA (Rocky Mtn Lab) has one, but it seems skewed towards forest fire impacts and it seems to indicate harvesting as little impact on runoff. It does show the huge impact road building can have on forest runoff.

The potential of using these models for education really great. I can see using these at a workshop for landowners; pull up the map for their property and run scenarios on thinning, harvest, timing of harvest (can it help to carry out harvest in stages) and whether or not you use BMPs and how this all affects the bottom line of runoff. The models could also be used in comp planning and development approvals.

There are lots of limitations of these models and if garbage goes in, garbage comes out. But they look like useful tools, and I wonder if others have any interest in learning more about these models? Perhaps ask for a rerun of the webinar or asking these guys to come up to our region so we can get trained in using them. How does info like this get disseminated in our region?

The session and materials are provided by the Great Lakes Commission and they have asked for ideas on how to get the word out about these models and for input on their materials. More info is at their website.

Thoughts?