Floodway: Part of War on Mosquitoes?


Floodway: Part of War on Mosquitoes?

This summer, a strapping young tourist from California visited Winnipeg for the first time. An engineer and U.S. Navy veteran, Joe stood out as a hardy chap. Yet, when asked if he had enjoyed his vacation, he replied, "No." He praised the climate, the geography and the people he had met, but one element alone had soured his experience. The spoilers were mosquitoes.

Winnipeg's topography makes it particularly vulnerable to the mosquito: a flood plain covered with Red River clay can't absorb standing water very well, so every rainfall creates abundant breeding territory. We will probably never conquer the mosquito completely under these conditions. But the annoyance factor, which kills tourism, and the danger of disease, which can kill us, means that we should try.

What more can be done to minimize mosquito infestations? First, we can inform citizens more effectively about steps we all can take towards that goal. More importantly, the Province and the City could take advantage of the pending Floodway expansion to tackle the problem of standing water.

These pests predate mankind. They once fed on dinosaurs, and thousands of varieties infest every climate on the planet. In rain forests, mosquitoes pass yellow fever from canopy monkeys to the foresters who chop down trees. Caribou along the Arctic Ocean can die from blood loss when attacked by aggressive swarms. The outcomes of historic military campaigns have been decided by which army had the best defenses against this persistent creature. Alexander the Great probably died of malaria.

The first boats spread mosquitoes to different habitats and increased global trade has expanded their range immeasurably. The tiger mosquito first arrived in Houston, Texas, inside Asian car tires sent for recapping. Mosquito eggs in the Negev Desert lay dormant for years until a few rare drops of rainwater restart their life cycles. The once vaunted DDT failed to solve the problem because mosquitoes soon developed complete resistance to it.

Given all this, the task of making Winnipeg mosquito-free seems daunting. Our first stage of defense, larviciding pools of nesting water with a bacterium which eats their intestinal walls, works. But the larval stage only lasts for twelve days and we can never get to them all. Only when a public health threat like encephalitis or West Nile virus arises do we fog with controversial insecticides like malathion, which kills the good bugs, too.

The most obvious line of attack is hinted at in media campaigns that urge Winnipeggers to rid their yards of breeding grounds. The insects thrive in uncleaned eavestroughs and in all kinds of human containers that lie neglected in back sheds and gutters. When the French first tried to dig the Panama Canal, they protected the trees in their lavish gardens from ants with pottery rings filled with water teeming with mosquito larvae. The Americans, who understood mosquito control, completed the project.

An investment that raises public awareness of man-made mosquito habitats is money well spent. These education efforts might ease the "micro" aspect of the mosquito problem, but they do not address the issue of geography. What do we do about the pools of breeding water that surround Winnipeg after every rain event? The province is about to spend $700 million to upgrade the Floodway, a laudable move that will both reduce the risk of flood damage and expand possible recreational uses. Why not go farther and make mosquito control an element of the project, for what is surely a marginal increase in cost?

Government water experts agree that the concept is feasible. A combination of ditches and pumping stations could drain standing water from the whole east side of the city into an expanded Floodway. If we're going to spend that much for a small increase in flood protection, why not try to meet another public purpose at the same time?

The other sides of the city are more problematic. Thousands of acres of prime mosquito habitat, partly private property and partly public, lie outside the Floodway catchment. Adult insects can travel at least ten miles during their months of life, even without helping winds. A war on mosquitoes in these areas would require more drastic steps.

The government already has the power to enter private lands for larviciding. The imposition of more rigorous mosquito control by means of mandated, probably subsidized drainage systems may seem a drastic step, but it will form a necessary part of a serious effort to liberate us from mosquitoes. Surface drainage within the city and at its edges must be reviewed property by property to assure adequate surface drainage. If necessary, regional pumping stations and expanded storm sewers should be built. Swamp drainage projects have had an impressive record of success in reducing the mosquito problem in cities throughout the world.

Sixty years ago, in northeastern Brazil, an American named Fred Soper proved that an extraordinary effort could rid a large region of the mosquito scourge in a single year. He believed that eradication was possible and preferable, by combining water control, spraying and widespread public participation.

Winnipeg has the best summers in the world, but they are quite short. We can make them immeasurably more attractive to residents and visitors alike if we conquered the mosquito. This is one case where more money, combined with some creative thinking, can deliver better outcomes.

Let's get rid of floods and mosquitoes, at the same time.