Codd Wetland is a significant feature within the Alouette River watershed.  The Alouette River runs approximately 25 kilometers from Alouette Lake to the Pitt River confluence with approximately 35 tributaries. This watershed is located in the Districts of Maple Ridge and Pitt Meadows and covers approximately 300 square miles. The watershed is bordered by the Coastal Mountains to the north and east. To the south, a low hill separates tributaries which drain into the Alouette River from those which flow to Kanaka Creek or directly to the Fraser River. The western area of the watershed is within the Pitt Polder, an extensive area of flatlands which is very close to sea level.    The Codd Wetland property is found within the Pitt Polder region and being so close to sea level the wetlands are influenced by the tide through the Pitt – Alouette River system.  

This tidally influenced fen wetland is dominated by grass and shrub vegetation and open stream channels.  The majority of the property is dominated by Reed Canary Grass and patches of Sweet Gale and Hardhack.  These grasses and shrubs provide important roosting and nesting areas for many bird species including the red-listed Greater Sandhill Crane.  A section of the North Alouette River flows through the southwestern portion of Codd Wetland and both the north and south arms of Blaney Creek, a tributary of the North Alouette, transects the property as well.  McKenzie Creek and several smaller watercourses provide upland drainage flowing directly down into the wetlands.   

Codd Wetland is partially visually isolated due to its proximity to large upland mature forest on the east, a forested Codd Island on the west, and a corridor of mature trees along the north.  The sense of isolation this provides along with the vegetation type,s and ratio of open water, combine to provide a unique habitat for a variety of fish and wildlife species.  The wetlands are officially recognized as environmentally unique within the Lower Fraser Valley.  The Canadian Wildlife Service (CWS) of Environment Canada recognizes the area as an important wetland.  CWS has designated the area as Fraser Lowland wetland site 124 and has given it the highest rating.   The Ministry of Water, Land, and Air Protection and the Department of Fisheries and Oceans both consider the Codd Island wetlands to be an important aquatic Environmentally Sensitive Area.