I am glad to see discussion has been sparked on this topic...
After seeing Telico closed for water issues and Carnegie on the verge of closure for water issues and Rubicon under attack for water issues...
And, Forest Service and state water boards are beginning to push watershed protection in order to ensure water quality...
I helped Friends of the Rubicon/Rubicon Trail Foundation develop their presentation to the Central Valley Water Control Board that countered the environmental groups pressure to close Rubicon. PEER and Trout Unlimited used photos of 4x4s in water lifted from web pages and forums as their supporting documentation to the damages OHV is causing to the water supply.
I am meeting with Forest Service on their Water Quality Management Plan for California Forests. Other Forest nation wide will be undertaking similar planning in the coming months.
And, when water quality boards (functioning under EPA mandates) become involved, it doesn't matter if it is public or private lands.
Private land owners are REQUIRED to contain sediment runoff to their own property.
Check out Texas Motorized Trail Coalition and their work at Barnwell Mountain.
Water and recreation are VERY sensitive topics and yes, I do tend to get a little course WRT water and wheeling.
The point to take away is short and simple:
The environmental community is beginning to lose on endangered species issues and are turning their attention to two other issues that are easy targets: WATER and AIR quality.