GRCA has a regulation that requires any development proposed to be undertaken around features that include watercourses, floodplain, valley slopes, and shorelines to obtain permission from the Authority to ensure that the development is safe and does not further exacerbate the hazard(s).  Further, with respect to wetlands, that the proposed development or interference does not have a hydrological impact.

The regulated area includes the hazard (watercourse, floodplain, erosion hazard) plus a distance of 15m from the anticipated limit of the hazard.  
GRCA regulates a distance of 120 metres from all provincially significant wetlands and wetlands greater than 2 hectares in size. GRCA regulates a distance of 30m from all other wetlands.

No. If you fall within a regulated area, it means that GRCA must determine that the development is safe, does not further exacerbate the hazard(s) or, in the instance of a wetland, does not have a hydrological impact. Once this is demonstrated, a permit will be issued. GRCA has a policy document that provides a framework under which application for permission can be consistently and comprehensively assessed.

Development includes (but is not limited to) the following:

• Construction or demolition of buildings or other structures (e.g. house, garage, shed, deck, etc.)
• Site alteration, placement of fill or grade modifications. Fill can include gravel, rock, sand, soil, etc.
• Installation and/or replacement of bridges, culverts and water control structures
• Any shoreline alterations including docks, boathouses, erosion protection, etc.
• Any realignment, channelization or dredging of a watercourse
• Any changes in grade adjacent to a wetland or vegetation removal in a wetland

Changes in use (ie: commercial to residential, new basement apartment, conversion of a garage to a habitable space).

In certain instances and in specific circumstances. A permit from the GRCA will be required.  
If you have an existing retaining wall or there is a demonstrated need to protect the shoreline (ie: house at risk due to erosion), protection can be permitted, but GRCA will require that a qualified professional shoreline engineer undertake the design to ensure that the hazard is addressed.  
Please refer to GRCA’s Lake Ontario Shoreline Management Plan for more details or contact GRCA staff.

In general, GRCA discourages new docks on Lake Ontario
A permit is not required for a removable dock (ie: floating dock) but a permit would be required for the anchor point (permanent structure).  
In general, new permanent docks are not supported.

A permit would be required for a dug well, whereas a permit for a drilled well does not required a permit.

No permit is required from GRCA to cut down trees unless the trees are within a wetland.  Vegetation removal in a wetland is regarded as an interference with a wetland and therefore a permit would be required in this instance.

Please check with Region of Durham or Northumberland County with respect to tree cutting.