The VNF publish, in advance, notice of chomages
(works). These are available for 2010 and for 2011 on the VNF website
I've been prompted and seen that the Canal entre Champagne et Bourgogne (Marne a la Saone, as was) - one of the routes between Paris/Northern France and the River Rhone/Mediterranean
- is due for some navigation interrompus
between 10th May and 6th June 2010. This is quite unusual, outside the winter months, and I've just talked to VNF at St Dizier who do confirm complete closure during those dates.