Lake Ontario St. Lawrence River Plan 2014

Coastal Flooding and Erosion

Comment Received

IJC Response

Plan 58DD has caused a great deal of coastal damage. Plan 2014 will increase damage to coastal property.

Plan 2014 retains most of the coastal-damage reduction benefits provided by Plan 58DD. Almost all the incremental coastal impacts of Plan 2014 relate to shore protection structures, not the flooding of buildings. Because there will be a small increase in the frequency of high water levels on Lake Ontario, costs to maintain shore protection structures, such as shore walls and revetments, will increase under Plan 2014. The same new shore protection structures will be required under either plan but the slightly higher Plan 2014 costs counted under “erosion to developed unprotected parcels” reflect the fact that protection will be needed sooner under Plan 2014. 


Plan 58DD has dramatically reduced coastal damages that would have occurred without regulation by reducing the severity and duration of extreme high-water level events. 58DD eliminates about 98 percent of the first floor flooding damages that would have occurred without regulation along the Lake Ontario coast, 99 percent of the flood damage on the upper St. Lawrence River and 70 percent on the lower St. Lawrence River. Damages to shore protection structures on Lake Ontario under Plan 58DD are less than half what they would be without regulation.


[The change in the low trigger levels has a negligible impact on coastal damages since the change only raises the lowest levels and coastal damages are not sensitive to the small rise in the lowest levels] 

Plan 2014 will cause devastating floods.

Structures at risk of flooding under Plan 2014 are also at risk of flooding under the current plan. Both Plan 2014 and Plan 1958DD prevent substantial property damage and perform similarly during extreme high-water events. During the most extreme high-water events, Lake Ontario levels will be about two inches (6 cm) higher under Plan 2014 than Plan 1958DD. Preliminary indications are that Plan 2014 will not change floodplain delineations.

Plan 2014 will cause homes to be lost to erosion.


The same homes that will be lost to erosion under Plan 2014 will be lost to erosion under the current plan, 1958DD. Property owners in erosion-prone areas will need to consider protective measures regardless of which plan is in place, but will likely need to take them sooner under Plan 2014. Because water levels are higher at times under Plan 2014, some increase in erosion rates will be expected. The difference will depend on the location and composition of the shoreline.  

Homes have been built based on the expectation that the rules for regulating water levels would not change.

Structures that were adequately designed and built to withstand conditions that occur under the existing regulation plan will see no significant increase in risk under Plan 2014.  

We were promised a four-foot range on Lake Ontario.

The IJC’s 1956 Order does not promise a four-foot range. No regulation plan can restrict the levels of Lake Ontario to a four-foot range. Plan 1958DD compresses levels to within a four-foot range, as nearly as may be, when natural water supplies do not exceed those used to design the plan (those from 1860 to 1954). Lake Ontario levels can go outside of this range when natural water supplies are more extreme than the design range, which has occurred on a fairly frequent basis since 1960. The potential for levels outside the four-foot range was acknowledged in the 1956 Order, and is the basis for deviations under criterion (k) of the Order. In reality, Lake Ontario has experienced more than a six-foot range since 1960 under Plan 1958DD. The range under either plan could be greater if future water supplies are more extreme than those experienced to date. Structures designed to withstand only a four foot range of water levels are likely to suffer significant damage under either plan over the span of a few decades.

The IJC continues to provide ridiculously low cost estimates for shoreline property owners. The costs to counties, towns, and municipalities have been ignored. These costs will be astronomical for infrastructure, roads, water treatment plants, sewage treatment plants, and water and electric distribution systems.

The analysis used by the IJC provides a reliable basis for selecting a regulation plan. The analysis focused on the most significant impacts that will result from a change in regulation plans. The decisions about which impacts to study and how to evaluate them were made carefully by the Study Board with the advice of independent economic advisors and basin stakeholders on the Public Interest Advisory Group. While not every effect could be accounted for, the IJC is confident that no major classes of impacts were ignored.  

The impacts to property on Lake Ontario’s embayments were not taken into account.

The analysis of Plan 2014 does include potential flooding impacts to embayments on Lake Ontario. Shore protection impacts were not estimated, because they are driven to a great extent by wave damage that is a more significant factor on the open lake than in the embayments.

Beaches have disappeared under Plan 1958DD. How will Plan 2014 affect our beaches?

Beaches are a dynamic feature of the coastal zone. In natural systems, beaches are built and destroyed by natural forces. The Study Board drew no conclusions about the effects of different regulation plans on beaches. While the occasional lower water levels under Plan 2014 provide favorable conditions for rebuilding beaches in certain areas, it is not clear whether enough material is available due to the high percentage of Lake Ontario shoreline that has been hardened or developed. Shore protection structures reduce erosion, but with less erosion, there is less sand in the nearshore zone to build beaches nearby.

Why doesn’t Plan 2014 contain a provision to help property owners mitigate the damage from higher levels?

The authority to mitigate risk to property and infrastructure in the coastal zone through permitting, financial assistance or other means rests with governments, not the IJC.

Plan 2014 is a “taking” without compensation because it increases erosion.

Erosion occurs under any regulation plan and the IJC does not believe that the potential small increase in erosion rates under Plan 2014 constitutes a taking of property. The determination of when a taking occurs is a complex matter governed by domestic laws in the United States and Canada.

Restoring the environment is important, but why have you not developed a plan that helps restore the environment that will not increase the risks to shoreline property owners?

No plan can do both. Despite intensive efforts to explore every promising alternative over the last 14 years, no plan has been found that addresses the environmental damage caused by Plan 1958DD to a meaningful extent while fully preserving that plan’s protection of shoreline property owners. After testing and modifying numerous alternatives, the IJC finds that Plan 2014 reduces the impact to shoreline property owners the most while still allowing water level fluctuations to nourish wetlands and preserving benefits for other upstream and downstream interests.