Lake Ontario

About Lake Ontario

Lake Ontario is similar to Lake Erie in length and breadth (193 miles by 53 miles). Yet with its greater average depth (approximately 283 feet), Lake Ontario holds almost four times the volume (395 cubic miles) and has a retention time of about 6 years.

The drainage basin covers parts of Ontario and New York, and a small portion of Pennsylvania. Major urban industrial centers, such as Hamilton and Toronto, are located on its shore. The U.S. shore is less urbanized and is not intensively farmed.

Partners working together

In addition to being part of a large, complex system, each Great Lake possesses unique attributes that warrant specifically tailored approaches to restoration and protection. A key mechanism for identifying priorities and coordinating restoration actions at a lake basin scale are Lakewide Action and Management Plans (LAMPs). LAMPs are plans of action to assess, restore, protect and monitor the ecosystem health of each Great Lake and its connecting river system. They provide a mechanism to coordinate the efforts of government and nongovernmental partners working to improve the lake's ecosystem.

LAMPs are called for in the Lakewide Management Annex of the 2012 Great Lakes Water Quality Agreement. Under this binational agreement, Canada and the United States have committed to: “contribute to the achievement of the General and Specific Objective of this Agreement by assessing the status of each Great Lake, and by addressing environmental stressors that adversely affect the Waters of the Great Lakes which are best addressed on a lakewide scale through an ecosystem approach.”

LAMPs are established for each of the five Great Lakes and their connecting river systems, as follows:

The Lake Ontario LAMP, 2018-2022, was developed by member agencies of the Lake Ontario Partnership which is a collaborative team of natural resource managers led by the governments of the U.S. and Canada, in cooperation and consultation with state and provincial governments, tribal governments, and watershed management agencies committed to restoring and protecting Lake Ontario, the Niagara River and the St. Lawrence River. In preparing the LAMP, the Lake Ontario Partnership also sought input from scientists, First Nations, Métis, stakeholders, nongovernmental organizations and the general public. The purpose of the LAMP is:

    • to summarize the current state of Lake Ontario in relation to the nine General Objectives of the GLWQA and point out key threats;
    • to outline actions that will be taken to address the threats and contribute to the restoration and protection of water quality in Lake Ontario; and
    • to engage all groups and individuals in the Lake Ontario basin to take action in protecting the water quality in Lake Ontario.


What we do

Blue Accounting is an information service to track the region’s progress toward shared goals for the Great Lakes. Maintained by the Great Lakes Commission, the information developed by Blue Accounting helps elected officials make sure that policies and programs are effective at protecting the largest fresh surface water system on earth.

What we measure

The Great Lakes Commission’s Blue Accounting team works with experts to identify goals and methods to track progress on key Great Lakes issues. Currently, Blue Accounting is tracking progress on protecting the region from aquatic invasive species and keeping phosphorus out of Lake Erie.