Water flows downhill at any angle, even those hard to see with your naked eye. If you're even slightly uphill of a nearby waterway, your site can be a major source of erosion as you move around dirt and destabilize the soil.Some waterways have private owners, while others are managed by a State department or other local jurisdiction. These parties will usually have specifics about the amount of turbidity allowed to increase due to your project's impact.
Destablizing soil within the water will be a major source of turbidity as well. You'll often see turbidity curtains in dredging projects, while teams are cleaning up the bottom of a lake or pond. As this picks up mass amounts of silt and sediment, it's important to control where these particles flow, and eventually settle.
