River Watch 2019

RIVER WATCH 2019 # 6

As of Monday, May 20th, the level of Lake Ontario was still 4.3” below the record set in 2017. The International Lake Ontario – St. Lawrence River Board (ILOSLRB) has indicated that the level of Lake Ontario is expected to continue to rise over the next several weeks and may exceed the 2017 peak. Unfortunately, the level of the St. Lawrence River at Brockville has at times exceeded the 2017 peak levels for the past three days. Levels are up to 4 inches above the 2017 peak. Some of this may be due to wind surge.

Outflows at the Moses-Saunders Dam in Cornwall have been increased. The ILOSLRB has indicated that further increases in outflow are expected as conditions allow.

The raised river levels are causing issues for property owners. Many who were affected by high levels in 2017 have sandbagged and are using multiple sump and portable pumps to keep water out of basements and crawl spaces.

A number of residents who did not have major issues in 2017 are now experiencing water issues despite the river being below their residences but not below the bottom of their basement or crawlspace. The high river level is causing a phenomenon known as hydrostatic pressure. The high levels cause the normal water table surrounding homes to rise, thereby forcing water into basements and crawlspaces (through sump holes and any minor cracks in the foundation walls or floor). To help counter this issue, residents should ensure they have a good sump pump with at least one backup unit (preferably a battery backup unit should the power fail).

Increasing winds are also causing concerns about shoreline and lawn erosion. A sandbag wall can help prevent this situation. For those individuals with a sea wall or a firm shoreline, another approach would be to construct a flashboard wall that can be tied into solid objects or earth works at a higher elevation. This approach consists of rough finish ½ or ¾” plywood. The height would vary depending on the height of the sea wall. A minimum height of 24” should counter wave action. The plywood is attached to 2×4’s at the base which are in turn attached to the concrete wall or to stakes driven into the ground. The top of the plywood should also be tied in by 2×4’s. Then a 2×4 can be angled from the top 2×4 to the ground and secured with a stake. Periodic sandbags would add additional support.

A supply of sand will continue to be maintained at the MERC Hall in Maitland. For those requiring sandbags for residential protection, please contact the municipal office. Sandbags for other purposes are also available locally or the office can provide a list of sandbag suppliers.

Sent: May 21, 2019

RIVER WATCH 2019 # 5

By all indications, the next few days are ones that the adage “Hope for the best, plan for the worst” can certainly be applied to.

From a weather perspective, a “Texas Low” pressure system moved into the province yesterday. While expected to predominately track through northeastern Ontario, it will also have a direct effect on eastern Ontario. Precipitation amounts in the 20-40 mm range are forecast for our area. The attached Weather Network chart shows the degree of expected impact.

map of ontario showing how much rain certain area are expected to get

This storm system, if as severe as predicted, will have a multi-pronged effect on high water levels in our area. Forecasts are also calling for strong winds, waves and potentially storm surge. Residents should expect to note fluctuating water levels throughout the weekend.

The Lake Ontario and St. Lawrence River watersheds may receive anywhere from 20 to 40 mm of rain. That precipitation will have a direct impact on lake and river levels, aggravating the already high levels over the short term.

The system tracking through northeastern Ontario may bring 20-60 mm of precipitation. As well as causing any remaining snow to melt faster, the water will work its way down the Great Lakes system and end up in Lake Ontario at some point in the future. That water will help maintain high levels on Lake Ontario and in turn the St. Lawrence River.

To further complicate the situation, the storm will also impact the Ottawa River watershed. That watershed is already seeing increased flow effects in the Mattawa area. This storm will further aggravate that situation. With additional water coming down the Ottawa River, the increased flows may cause water levels in the Montreal area to rise again. If that happens, the International Lake Ontario-St. Lawrence River Board may have to reduce outflows from the Moses-Saunders Dam. Current outflows are 7600 cubic metres/second.

Update: Overnight Thurs./Fri., flows were reduced to 7400 cubic metres/second. A further reduction to 7000 cubic metres/second is to occur at 0900 Friday morning.

Residents should remain vigilante to changing water levels and adjust their protective measures (sandbag barriers, weights on docks, etc.) accordingly. Sand for sandbagging is available at the MERC Hall.

If anyone has any questions with respect to this bulletin, please email emergplan@augusta.ca.

Sent: May 10, 2019

RIVER WATCH 2019 # 4

As of the International Lake Ontario-St. Lawrence River Board’s May 6th information release, Lake Ontario was at 75.51 metres. The lake was 51 cm or 20.1 inches above the average but 14 cm (5.5 inches) below the level set on the same date in 2017. As importantly, the lake is 37 cm (14.6 inches) below the highest level recorded on May 25, 2017. That level was 75.88 metres.

As of last night Lake Ontario outflows at the Moses-Saunders Dam has been increased to 7,000 cubic metres/second. Further adjustments will be made in accordance with Plan 2014.

The weather forecast projects precipitation starting Wednesday evening and ending early on Thursday will bring 20-50 mm of rain to Eastern Ontario. If the full 50 mm is received within the Lake Ontario and St. Lawrence River watershed, this will have an impact on water level increases.

A Notice to Shipping reducing speeds on the river was issued on April 26. A second Notice was sent out on May 01, 2019. Both notices advise shipping that “vessel speeds will be monitored closely and there will be zero tolerance for vessels exceeding the speed limit”. Having observed a couple of ships this afternoon, they appear to be following the directives. If you do notice heavier wave action, particularly at night, from a passing ship please note the time of passing so that we can follow up with the appropriate authorities.

Residences affected by the high water situation in 2017 have all been sandbagged by their owners. Should the river level start to approach the high of 2017, the municipality has sandbags available for year round home protection. Please contact the municipality and a representative will be in touch. We also have a supply of sand established at the MERC Hall in Maitland for anyone who needs it for flood protection.

Sent: May 06, 2019

RIVER WATCH 2019 # 3

As of today, the level of Lake Ontario is at 75.38 metres above sea level which is 0.01 metres above the lake’s flood stage. The lake is still 0.43 metres or 17” from its peak level of 75.81 metres sent in 2017. Given the amount of inflow from the other great lakes and the precipitation forecast over the next few days and into early next week, the lake level is expected to continue rising.

The International Lake Ontario-St. Lawrence River Board (ILO-SLRB) increased the level of outflow at the Moses-Saunders Dam yesterday to 6100 cubic metres/second. As flows on the Ottawa River subside, it is hoped that St. Lawrence River outflows can be increased further.

On April 26, 2019 a Notice to Shipping was issued that implemented a vessel speed reduction along the St. Lawrence River. Residents are advised that wave action will still occur from passing ships. However, if you notice waves from a passing ship in excess of what would now be normal, please email emergplan@augusta.ca with the information. Please note the time of the ship’s passing and if possible, a description of the vessel.

Several residents in Augusta Township who were affected by the peak flows of 2017 have put in place sandbag retaining walls in preparation for increased flows.

A stockpile of sand is available at the MERC Hall in Maitland for any residents filling sandbags.

Sandbags will be available to residents whose residences are imminently threatened subject to an inspection by the municipality and approval by a municipal official. Residents wanting to protect anything other than their immediate residence (i.e. docks, shoreline, boathouses, cottages, etc.) can obtain a LIST of sandbag suppliers from the township office. Local hardware stores and lumber yards may also stock sandbags.

The attached chart, produced by the ILO-SLRB outlines the current situation on Lake Ontario and on the St. Lawrence River. Updated charts are available on their Facebook page.

Also today, South Nation Conservation released their Flood Watch: St. Lawrence River – Update # 1.

Sent: May 01, 2019

RIVER WATCH 2019 # 2

Environment and Climate Change Canada are forecasting upwards of 40 mm of rain over today and Saturday.

According to the International Lake Ontario – St. Lawrence River Board, Lake Ontario levels are expected to further increase. The expected increase is a result of the forecast precipitation, inflows from the upper great lakes, and reduced outflows due to the flooding situation in Montreal. The flow reduction from the Moses-Saunders Dam and the situation in Montreal are a direct result of the flooding currently occurring on the Ottawa River and its tributaries.

April 25th Lake Ontario outflows were at 5700 cubic feet/second as compared to 7600 cubic feet/second on April 18th.

The current water elevations are also causing concerns with respect to wave damage from passing ships. As a result, the St. Lawrence Seaway Management Corporation will be sending out a Notice to Navigation today requiring ships to reduce speeds by up to 3 knots between the Eisenhower Locks at Massena and the outlet of Lake Ontario. If water levels continue to increase, we will probably see additional speed reductions.

If anyone has any questions, please email emergplan@augusta.ca and someone will get back to you.

Sent: April 26, 2019

RIVER WATCH 2019 # 1

Lake Ontario and St. Lawrence River water levels are on the rise. The International Lake Ontario – St. Lawrence River Board (ILO-SLRB), in a recent release, stated that “there is a potential for a relatively significant and rapid rise in Lake Ontario levels”. The anticipated rise is stated to be well within the confines of Plan 2014.

As of April 18, the lake was 23 cm or 9.1” above the average.

A number of factors are contributing to the rise in levels:

  • Recent rainfall projections for Southern Ontario over the long weekend called for 30 to 60 mm. Locally, rain gauges in Spencerville and Brockville recorded 32.4 and 37.2 mm respectively between April 18 and April 20, 2019.
  • Lake Ontario is receiving slightly higher flows from Lake Erie than what is the average (ILO-SLRB report)
  • According to local newspapers, the gates of the Iroquois Dam have been closed. Recreational water craft will not be able to use the dam to move up or downstream. The Iroquois Dam is used for flood management by Ontario Power Generation. Gates will be adjusted to control the level of Lake St. Lawrence between Iroquois and Cornwall.
  • Outflows from the Moses-Saunders Dam at Cornwall are being adjusted as the flows in the Ottawa River watershed increase. The reduced flows at Moses Saunders are meant to help minimize flooding at Montreal and Quebec City. Outflows on April 18 were noted as being 7,600 cubic meters per second. The outflow for the previous week was 8,660 cubic meters per second. The long-term average outflow for last week was shown as 7,190 cubic meters per second.

During a flood conference call on Sunday, April 21, a representative of the ILO-SLRB indicated that there were no issues from a flooding perspective on Lake Ontario and the St. Lawrence River. There is no indication that levels will reach the 2017 peak elevation given the current inflows and weather forecasts. In order to repeat the 2017 situation, the Lake Ontario watershed would need to receive 2 or 3 major storms similar to 2017.

Augusta Township personnel will continue to monitor water management agency reports and the actual local situation. Updates will be provided as new information becomes available.

Sent: April 22, 2019

Following the spring high water levels on the St. Lawrence River in 2017, Augusta Township initiated a River Watch newsletter in 2018. Periodic emails from the municipality informed subscribing riverfront property owners of water levels on the river during the April/May period. The municipality is considering initiating the same newsletter for 2019 if water levels begin to rise above normal operating levels.

If you are a riverfront property owner and would like to be included on our distribution list please email emergplan@augusta.ca. The email needs to include the following information: civic address; homeowner’s name(s); email address and a contact telephone number (this is optional). All information given will be kept private, including email addresses.

Going forward, the newsletter will also be posted here.

Sent April 9, 2019