What Causes Flooding?
Flooding is commonly defined as “a rising and overflowing body of water especially onto normally dry land” and legally as “a general and temporary condition where two or more acres of normally dry land or two or more properties are inundated by water or mudflow”. There are several fundamental contributing factors:
Storm surge is the displacement of water due to hurricane activity, and is recognized as the most dangerous component of hurricane events. The powerful winds push the water inland at the speed of the forward motion of the hurricane. Forward speeds of hurricanes are generally between 10-35 mph depending on the latitudes. Storm surge can appear as early as 24 hours prior to landfall, which tends to take people in affected areas by surprise. Considering that a cubic yard of water weighs 1728 lbs., a single foot of storm surge has sufficient power to cause devastating destruction to buildings and homes. The highest storm surge ever recorded in the US happened during Hurricane Katrina when 27.8 feet were measured at Pass Christian, Mississippi. Pass Christian was also the site for the second highest storm surge ever recorded, which occurred during Hurricane Camille in 1969.
According to the National Weather Service, the 12-month period ending April 30, 2019 was the wettest on record. Between a wet fall, an exceptionally wet winter, an above average 2018 hurricane season, and atmospheric rivers, the continental US has been hit with an average of 36.2 inches of precipitation. This development is in-line with the projected increase in precipitation as a result of rising temperatures worldwide. Warmer air holds more moisture. However, elevated temperatures also evaporate water, causing areas with less propensity for rainfall to quickly dry out. California provides a prime example of how the two mechanisms result in greater polarity of weather conditions with some areas experiencing severe rainfall and flooding, while other regions suffering from withering drought.
Melting of Snow and Ice
Precipitation, of course, occurs during all seasons in various forms. Accumulation of snow and ice can play an important part in rising water levels and subsequent flooding as it thaws at the beginning of spring season. According to the United States Geological Survey (USGS), up to 75% of water in some western states come from melted snow.
Flooding in Lake Ontario
At the end of June 2019, the water level in Lake Ontario was approximately 34-inches above average. Due to the Lake’s positioning as the lowest of the Great Lakes and the downhill flow of water, gravity is the main culprit for the compounding water level rise. Due to above-average rainfall for all of the Great Lakes this year, much overflow from other Lakes has pushed into Lake Ontario. Combined with the rain and melting snow it has already directly received, Lake Ontario is literally spilling over the brim. Water can be released into the St. Lawrence River by the International Joint Commission, though this process can be slow moving for reasons to be addressed.
From a technical perspective, lowering the water level in Lake Ontario, the 13th largest lake in the world, is not an easy task. Generating a 1-inch drop in water levels causes the Saint Lawrence river to rise by 11-inches in Montreal, which has a population of 1.75 million people and is surrounded by the St Lawrence and Ottawa rivers making it particularly vulnerable to elevated water levels in the rivers. The Ottawa River’s water levels hit record levels during the 2017 flood, and this year it’s even worse, creating a challenging water-flow management system, as the International Join Commission must wait until the Ottawa River subsides before they can start lowering the water levels in Lake Ontario.
Lowering water levels is also a time consuming process due to the sheer volume of water within Lake Ontario itself. Even with record level outflows of 2.75 million gallons per second, it takes 30 days to drop the water levels by 4 inches according to United States Army Corps of Engineer (USACE) estimates.
As previously mentioned, this is far from the first instance of flooding in the Lake Ontario area. Severe flooding in 2017 spawned a new set of regulations known as Plan 2014, which was approved in December 2016. Essentially, the Plan acknowledged that water levels would be higher going forward, with an increased possibility of more severe shoreline erosion and flood damage in New York State.
New York State in turn declared a state of emergency and allocated $100 million for repairs due to extensive damages due to flooding. The plan also adjusted the projected annual damages to lakefront property to $20 million, up from the previous estimates of $18 million. Plan 2014 also estimated that the average increase in water levels would be 2.4 inches. Interestingly, by the second week of 2017, the water levels were above the 100-year average with no signs of falling back.
The levels remained high for 87 consecutive weeks until September 2018. Subsequently, the USACE confirmed that the levels in June 2019 were 32 inches higher than the long-term average, and 3 inches higher than the record levels of 2017. On Aug 22, 2019, it was decided to reduce outflows from Lake Ontario by 10,000 cubic feet per second, which translates to roughly 1 cm over the course of a week.
Outflows - Who Decides When and How Much?
The International Joint Commission decides when to lower the levels in Lake Ontario. The commission consists of six members, three representatives from the United States and Canada apiece. A tie vote means no decision is made and no action is taken, which creates a conflicting dynamic. On one side, the US representatives desire to push water from Lake Ontario to lower it, while on the other side, Canadians representatives are sensitive to increased outflows through the Moses-Saunders Power Dam and the rivers surrounding Montreal. Suffice it to say, the political management of Lake Ontario water flows can be cumbersome and slow.
As a response to Lake Ontario’s current flood crisis and in May of 2019, Governor Andrew Cuomo launched the REDI program (Resiliency and Economic Development Initiative), a multi-agency task force assembled in order to enhance the infrastructure in the affected areas in areas around Lake Ontario. New York State has earmarked up to $300 million in order to tackle current issues and prevent the shoreline from remaining equally vulnerable going forward.
According to an August 7 letter from the multi-agency REDI commission, up to $20 million will be set aside for grants accessible for homeowners who wish to purchase products/solutions in order to protect their land and property from the devastating effects of flooding. This process will be part of the NYS Department of Housing and Community Renewal Residential Home Repair Program. However, no specific details on how homeowners should proceed in order to access these funds have been announced at the time of writing this article. Coastal Innovations will ensure that the information is readily accessible when available.
Remaining REDI funds will be allocated to affected local governments for approved projects. Local governments are required to match 15% for every dollar the state spends, providing an incentive to make ensure the approved projects are real, meaningful, and of benefit to all stakeholders.
How Do I Protect My Home?
Sandbags have been a commonly deployed flood protection barrier for decades. However, they are not without their drawbacks. Sandbags are:
o Difficult and time consuming to deploy
o Expensive (unless USACE provide them for free in crisis situations)
o Not very effective (many gaps and not a single wall of protection) and
o Able to be used for a limited period.
Most commonly, sandbags are basically untreated burlap sacks. When empty, bags can be stockpiled for a while. However, they deteriorate quickly when filled, and their effectiveness lessens with each deployment.
Polypropylene bags are also available and are essentially plastic bags that hold up well over time even with limited care. These bags are typically more expensive than burlap bags and must be disposed of correctly in order to prevent a negative environmental impact.
In both cases, the bags are packed with sand or sandy soil. Although sandbags allow for some flexibility in terms of which material used as fillers, it’s important to note that coarse sand is at risk of leaking through the weaves, and that a rockier material may cause the fabric to rip and loose its structural integrity. Given the average weight of 30 lbs. per bag, a two-man team can set up a protective barrier of a limited size with some heavy lifting.
o Best-in-class performance
o Able to secure Protection Zones at any required length and shape
As an alternative to sandbags, Coastal Innovations produces the FlexaPrism Dam (patent pending), provides durable and dependable inflatable dam systems to quickly and effectively protect your property and assets from the onset of flooding. The Dams are reusable water-filled bladder technology and replace the need for sandbags, which are more expensive and labor intensive to deploy and less effective.
Coastal Innovation Dams are rapidly installed with minimal manpower and no heavy equipment: a 50-linear foot section (with 30-inch wide base and 27-inch height) arranged by a single individual fills in approximately one hour. To protect the same length and height with sandbags, a dam would require 25 standard issue sandbags in length and 7 rows tall. Upon completion, the installer would have carried 5250 lbs. of sandbags!
FlexaPrism Dams are also fully customizable. They connect to create a protective barrier for any required length or shape via its proprietary Dam-Connection System. Simply arrange Dam sections as desired, connect, fill, and protect. Once the flood has receded, Dams are easily emptied away from the Protection Zone via drain outlets. Dams are then dried, folded, and stored for future use.
Dams are available in a variety of dimensions depending on specific flood protection needs, ranging from 20-50 linear foot lengths to 30-46 inches in height.
With record water levels that are slow to fall, residents of the Lake Ontario region face unprecedented water management challenges, state-of-the-art solutions are required to address the new reality of flooding, and Coastal Innovations offers a much-improved approach to flood protection. Please contact us to learn more about how Coastal Innovations can protect your property and assets.