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Addressing Flooding Along Navigable Waterways

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By Harry Valentine 12-07-2019 05:05:45

In recent years, high water levels and flooding has occurred along several of North America’s navigable waterways. While some of the flooding occurred during the early spring as winter snow and ice began to melt, other recent occurrences of flooding and near flooding have resulted from unseasonably high levels of rainfall. Beginning some 2,000 years ago, the engineers of the Mayan empire developed methods by which to reduce flooding along some rivers.

Introduction

Practically every year during early spring, flooding occurs along sections of the Mississippi River and requires suspension of commercial navigation. Springtime high water levels along the St Lawrence Seaway has on occasion, delayed the annual opening of the ship navigation season between Montreal and the Great Lakes. Extreme high springtime water levels that have resulted in flooding have occurred along smaller navigable rivers such as the Ottawa River and Richelieu that flow into the St Lawrence River. Seasonal flooding also occurs on the Red River that flows from North Dakota into Canada and into Lake Winnipeg.

At the present time, people who own waterfront property located around Lake Ontario and along the Upper St Lawrence River have organized into protest groups, the result of extremely high water levels that have caused flooding at waterfront homes along with related property damage. They have directed the protest at the International Joint Commission that oversees and manages water levels between the Great Lakes and Montreal. It is possible that changing weather patterns and a warming Arctic region are producing unusually high levels of precipitation and leaving conservation and regulatory agencies unprepared to manage the changes.

Reducing Water Flow

Many centuries ago, engineers of the Mayan empire built rock dams along the tributaries of rivers at high elevation to reduce and even prevent flooding along rivers at lower elevation. The strategy allowed Mayan farmers to cultivate food crops in the fertile land at the lower elevations, next to and near the rivers. There may be scope to re-introduce the Mayan method at the present day on a massive scale, to reduce water volume flow rate from high elevation to lower elevation in regions that experience downstream flooding, with additional potential to combine the Mayan method with modern permaculture.

Permaculture is a method by which water is transferred directly from above ground level deep underground into the level of groundwater, using pipes connected to an excavated underground cavern. Across the north regions of North America, the winter ice cover and frozen soil near the surface prevents water from melting snow and ice from seeping deep underground. Instead, that water trickles toward small streams that flow into tributaries of rivers that become prone to flooding. During the warm summer, several of the same regions that experienced severe springtime flooding later experience summer drought and a lack of groundwater.

Permaculture Experiment

There would be scope in northern rural locations to undertake an experiment involving springtime permaculture, to divert water from melting snow and ice deep into the ground at locations that have low summertime groundwater levels. Prior to the spring melting, a well or vertical bore hole would be drilled deep into the ground at a low point along drainage ditch, to install upper and lower plastic (PVC) pipes. The upper 20-foot (six-meter) long pipe would be solid tube while the lower level pipe would be of equal diameter and have holes drilled into its circumference, along its length. 

It would be commercially available pipe that would be wrapped in fine plastic mesh to keep out sand. When installed, it would extend from just under 20 feet below surface to 100 feet depth. The top of the solid tube would protrude above the ditch floor, with a hood installed above it to collect water and keep out dirt. As melting occurs during spring, water would flow into the vertical pipe and permeate into the deep earth to add to the groundwater. A successful result would provide a precedent for large scale implementation of the permaculture concept.

Combined Concept

The Mayan mini-dam concept proved workable over a period of 1,500 years for reducing flooding at lower elevations. Likewise, the permaculture approach has also proven successful in moving water through an almost impermeable frozen surface to deep underground into a low water table. Combining permaculture and Mayan concepts would involve connecting pairs of horizontal pipes to each Mayan style mini-dam installed along a stream. Each horizontal pipe would connect to multiple extended depth vertical permaculture pipes installed deep into the earth, to transfer large amounts of water from each Mayan min-dam deep into the groundwater.

A single experimental installation would demonstrate the volume of potential downstream flood water that could be diverted into the groundwater at each upstream location. The combination of a time-proven ancient Mayan flood control method and a modern permaculture concept is potentially workable. It could form the basis by which to implement the concept on a widespread basis in regions with low water tables, provided that different regulatory bodies and tribunals can find basis for cooperation. Implementation of the concept requires new cooperation involving the International Joint Commission along with state and provincial environmental and natural resources agencies. 

Citizens’ Participation

Many cities internationally such as Chennai, India encourage homeowners and landlords to invest in water storage tanks to store water on their properties. During summer, many North American cities ask citizens to restrict water usage. In such cities, authorities encouraging citizens to store spring melt water and rain water in storage tanks and in permaculture would contribute both to reducing downstream flooding as well as sustaining vegetation growth in urban areas. The cumulative result of several hundred thousand citizens taking such initiative translates into significant reductions in the volume of water accumulating at flood zones.

Elected authorities in rural areas can give citizens permission to install vertical permaculture pipes along drainage ditches in rural areas, to transfer spring time melt water and flood water from surface level to deep below ground surface. Authorities could also give citizens permission to build small Mayan mini-dams along small river streams, to slow water volume flow rate and also install pipes that transfer water from the mini-dams, through the still-frozen ground into deep level earth. The combined effort of thousands of small groups could manifest into significant reductions of flooding at the lower elevations.

Alternative Perspective

The Ottawa River is navigable between Ottawa and Montreal. During the spring of both 2018 and 2019, severe flooding occurred along the Ottawa River. However, a consultant who evaluated the flood situation rejected calls for the construction of upstream reservoirs along the Ottawa River to reduce flooding downstream. To the south and east of Montreal, the Richelieu River that experienced severe flooding during the 2019 spring, flows from Lake Champlain to the St Lawrence River. To the south of Lake Ontario, rivers flow from several “finger” lakes into Lake Ontario and Erie Canal.

The Richelieu River springtime situation adds credence to the suggestion that rejects construction of upstream reservoirs to reduce downstream flooding. However, the Mayan approach involves building small dams along the tributaries and streams that flow into rivers and into upstream lakes. A test or experiment involving the combination of Mayan mini-dams and permaculture that directly transfers melt water into the deep groundwater would provide information on the amount of potential floodwater that such a concept would transfer into the groundwater in regions that have a deep water table.

Water Diversion

While some regions in North America experience high water levels in lakes and streams, other regions experience severe water shortages and prompted initiatives in water diversion. In the north-central USA, one aspect of the Garrison Diversion plan calls for a summer time diversion of some water from the Missouri River into the Red River, to support commercial agriculture. The topography to the southwest of Lake Superior could allow for diversion of lake water over to the headwaters of the Mississippi River and then into the Red River, whenever lake water reaches excessive levels. 

During periods of excess high water levels on the Upper Great Lakes, a flow restriction based on inflatable technology and installed at the northern entrance of the St Clair River would reduce water flow into Lake Erie. High volume turbine-based hydraulic pumps installed between Lakes Superior and Huron would pump water into Lake Superior, as water transfers from Lake Superior to the Red River. As politically repulsive as water diversion may be to political activists, it offers a possible method by which to respond to excess height water levels on the Upper Great Lakes.

Predictable Weather Pattern

While weather patterns can be unpredictable, some weather trends can actually be reliable. One such reliable trend involves wintertime northern snow and ice melting after the end of winter and causing water levels to rise along rivers and downstream lakes, with most of the water flowing into the ocean. Despite frozen ground, it is technically possible using permaculture piping, to transfer a percentage of springtime melt water into the earth that is below the layer of frozen ground and especially in regions where the summertime water table is low. The piping would do its job every spring season.

Winters that involve excess snowfall would increase melting after springtime temperature rises, resulting in flooding along rivers and in the lower lakes. Methods to slow water flow rate along tributaries and transfer water deep underground, also transfer water from draining ditches to deep underground in areas with low water tables offers the possibility of reducing the severity of flooding along some rivers. During warmer weather, a slightly higher water table could provide additional groundwater to sustain agricultural production in some regions. There is going to be need for widespread discussion in regard to possible implementation of such methods.

Conclusions

There are possible methods by which to divert a percentage of springtime melt water away from rivers and lakes that would be prone to flooding. Around the North American Great Lakes region, it will be up to state, provincial and national tribunals, conservation agencies and regulatory agencies to decide as to whether to implement methods by which to transfer upstream melt water to bypass the frozen layer of ground and go into the deep groundwater.

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.