Tevis River Crossing

From: Steve Hallmark

Date: Wed, Oct 5, 2011 at 4:13 PM
Subject: Tevis River Crossing

Tom Johnson taught me a neat way to determine the river flow at
Poverty Bar where the Tevis Trail crosses the American River. Flow on
this section of the river is predominately influenced by the amount of
water being released from Oxbow Reservoir. Go to the following link:

http://www.pcwa.net/recreation/river-flows.html

Towards the bottom of the text on that page is a link to the CA Dept
of Water Resources page that displays the release data for Oxbow.

Or, try going directly to the CA Dept of Water Resources page for
Oxbow:

http://cdec.water.ca.gov/jspplot/jspPlotServlet.jsp?sensor_no=7712&end=&geom=&interval=&cookies=

You need to do a little simple math to determine the flow at Poverty
Bar. It takes seven hours for the release at Oxbow to effect Poverty
Bar.  So, add seven hours to the time reflected on the graph to
determine when that release will reach Poverty Bar.

The target CFS (Cubic Feet per Second) for crossing the river the
night of Tevis is 250 CFS.  This week, flows have been below 250 CFS.
I suspect they are possibly performing maintenance on the powerhouse
at Oxbow and are holding back water.

This summer, the flows would be up around 1000 CFS from about 0900 to
2400, then drop to about 350 CFS from 2400 to 0900. The river was
still safe to cross at 350 CFS, as we did so. A little high, but safe
in the daylight hours.

The rain we've experienced this week isn't enough to influence the
River flows. The ground is just to dry for any appreciable runoff.

Hope this helps.

Steve