Because of its colour, it is often nicknamed the "Chocolate River". The river is 129 km long and has a drainage basin of more than 2,000 km². There are approximately 175,000 people living in the watershed.
The river originates in various tributaries throughout the Caledonia Highlands of northwestern Albert County and western Westmorland County. The river itself begins in the village of Petitcodiac at the confluence of the Anagance River and the North River.
Major tributaries include:
From Petitcodiac, the river flows due east through a broadening valley past the village of Salisbury and then between the cities of Moncton and Dieppe, and the town of Riverview. At this point the river turns sharply south and drains past the village of Hillsborough before discharging into Shepody Bay at Hopewell Cape.
The 90º change in the course of the river at Moncton is responsible for the river's name. Petiticodiac is derived from the Mi'kmaq word for "bends like a bow". Incidentally, the city of Moncton was originally named "Le Coude" (the elbow) by early French settlers and was subsequently named "The Bend" by later English inhabitants.
The Petitcodiac exhibits one of North America's few tidal bores, a regularly occurring wave that travels up the river on the leading edge of the incoming tide, and hence a tidal wave in the truest sense of the term. The bore is actually caused by the extreme tides of the Bay of Fundy which, due to the rapid rise of the incoming water levels, forcibly sends a retrograde wave of water flowing upstream in tributary rivers that normally flow into the bay. This wave can vary in size depending on several factors including lunar phase and atmospheric pressure (storm surge) and is also influenced by the shape and the depth of the river. The incoming bore travels up the river on top of the outgoing water flow.
A commercial fishing industry existed on the Petitcodiac until the late 1960s (see Petitcodiac River Causeway) with species such as the Atlantic Salmon, Gaspereau (Alewife), Smelt and Sturgeon being important.
The lower Petitcodiac River Valley was originally settled by Acadians in the early 1700's. They established a number of farming communities on the shoreline of the river and the adjacent marshes. The valley fell under English control during the Seven Years' War, after the fall of Fort Beausejour in 1755. The Acadian population was subsequently expelled with English resettlement beginning in 1766 after the arrival of seven Pennsylvania Dutch families at The Bend (Moncton); re-establishing the pre-existing farming community. Initially agricultural, shipbuilding and railways would drive the valley's economy during the 19th and 20th centuries and would lead to the region becoming a major transportation, logistics and manufacturing area in the province.
Commercial shipping on the Petitcodiac River decreased in importance after the end of the wooden shipbuilding era in the 1870s, but the wharves of Moncton and Hillsborough remained active until the middle of the 20th century.
In 1968, the construction of the Petitcodiac River Causeway created a permanent blockage to the natural flow of the river; resulting in the creation of the Petitcodiac headpond on the upstream side of the causeway. Downstream from the causeway, the river began to fill with silt, reducing the effect of the once-famous tidal bore and altering the river channel for several kilometres. The river had formerly been navigable to commercial vessels upstream as far as Moncton, but the rapid siltation of the river put an end to this.
The causeway was intended to satisfy two goals:
The causeway is about a kilometer long, most of which is constructed on the flood plain. There is only a narrow sluiceway about 50 metres wide. This is normally kept closed. The causeway includes a fishway which was intended to allow fish to pass the causeway but this structure has proved to be ineffective.
The construction of the causeway had the following effects:
In the early 1970s, the regional garbage landfill was relocated to a point along the Moncton shoreline just below the causeway in order to allow for a "land reclamation" project. The landfill has since been closed and the site rehabilitated but there are persistent concerns regarding toxic "leachate".
On a more positive note; with the flooding controlled, the lands of the former flood plains along the river have been developed as recreational areas including walking paths, parklands and ballfields.
By the 1990s, the physical changes to the river were so apparent that citizens began to lobby to have the causeway removed, or at least to have the sluice gates opened up for a more natural water flow. This proposal was met with opposition from some residents concerned that the recreational value of the headpond would be lost and also from landowners along the shoreline of the headpond concerned with protecting their private land interests.
Concerned citizens seeking the removal of the causeway eventually formed Petitcodiac Riverkeepers. Robert F. Kennedy Jr. visited the area on several occasions to lend his support. A number of reports and studies by the provincial and federal governments were undertaken to determine how best to rehabilitate the river and a comprehensive Environmental Impact Assessment was released in 2005. This study concluded that the causeway should be removed and replaced with a 280-metre bridge to allow for natural water flow and restore fish passage.
In August 2007, the provincial government announced that the causeway gates would be opened and the bridge would be constructed to replace the causeway at a cost of $70 million. However, despite being a partner in the project, the federal government has refused to pay their share of the restoration project.
Despite the lack of federal government support for the project, public opinion is clearly on the side of restoration as are 9 of the 10 municipalities in the watershed. In addition, the Greater Moncton Chamber of Commerce has recently acknowledged the economic benefits associated with river restoration. Furthermore, in an unprecedented display of solidarity, student councils from all six high schools in the region banded together in 2007 in support of the river restoration.