http://www.northcoastjournal.com/041102/cover0411.html
A very clear picture, despite the objections and denials of timber companies doing the logging, is presented as to the effects of logging on sediment runoff into streams, etc., which often is the source for drinking water.
While water quality may not be significantly impacted, once the sediment and waste byproducts of a logging operation are allowed to 'settle' down to the bottom of the water flow, it could easily constrict, cause to make more shallow and more narrow, the channel through which the water flows. Much like a build up of placque inside blood veins and arteries.
A natural consequence would be an increased risk of flooding where the prior risk had been relatively low. Changing the natural ecology and structure of the area into a floodplain. Decreasing accessibility to homes in the area during flood-prone times of the year, thus decreasing the homes' very valuation by the tax assessor, thereby decreasing the homeowners' property value. Will insurance companies, in time, come to define this area as a floodplain and deny homeowners' insurance, without very costly flood insurance? Will such insurance companies even issue such coverage?