Part IV - Plenary Presentations and Keynote Addresses

Text of Keynote Address by the Honorable Rodrigo Carazo¹
Text of Luncheon Address by Sandra Postel¹
The Role of Environmental Education in Watershed Management
Water Resources as Eyewitness to the Health and Future of the Planet
Hydrometeorological Advances in Flood Forecasting in View of Lessons Learned from The Great Mississippi Basin Flood of 1993

Text of Keynote Address by the Honorable Rodrigo Carazo¹

Former President of Costa Rica

¹ P.O. Box 247-1250, San José, Costa Rica.

Developed countries have destroyed their natural resources and this is the price they have paid to achieve what we commonly know as “wealth.” The operation of the industrial complex continues to damage what little green space is left in the rich countries. Pollution is further exacerbated by automobiles and enormous urban development.

The damage suffered by our Planet intensifies and the dangers of the hole in the ozone layer and the greenhouse effect are common knowledge, just to mention only two examples.

The wealthy nations continue their harmful practices without curtailing their exorbitant resource consumption, which is well above the per capita average of the world. They refuse to regulate or change their customs and their waste. However, the dangers of a polluted environment grows everyday and the popular conscience in those rich and developed nations gives warning as to what is happening.

The curious part of the issue is that rich countries see the speck of dust in the others' eye but overlook the log in their own. The ecologists tend to point to the destruction of natural resources in the developing world as the sole cause of global environmental evils. Although experts acknowledge that contamination is contributed by the rich world, they specialize in blaming poorer nations for the difficulties that are now beginning to preoccupy them. They point fingers at others before “restraining themselves” and massively reducing the problems caused by their own societies.

One of the subjects of their preoccupation is the voracious destruction of tropical rain forests. The fact that poor countries are following the model of growth that the industrialized nations have followed for centuries is ignored. The international financial institutions make the poor nations “adjust themselves” to formulas that will permit them to live according to the practices in force in the rich world. The “foreign investment” - among other things - is oriented towards the use and abuse of natural resources in developing countries, who accept these practices in order to obtain the degree of growth and development that would allow them to be more equal with the rich.

Today's contemporary civilization has instilled the belief that to be rich is to have money. There are relatively few who think that true wealth is represented today by the Earth's green resources, which are capable of contributing to the absorption of carbon dioxide (CO₂) that contaminates the air; to maintain the temperature at normal levels; and to give oxygen (O₂) to all living creatures.

The rulers and the people of the poor nations ignore the fact that they are owners of real wealth (natural resources), whose existence and benefits freely provide all the inhabitants of the earth, including, of course, the owners of money (volatile wealth). The poor nations also ignore the fact that the rich countries are adopting a conscience which requires a conservationism that they refuse to practice, but which increases their responsibility towards our poor world.

For centuries, the zeal for conquest and dominion of the strong over the weak has been to obtain volatile wealth. We might then conclude that control over territories could prove threatening to those who are considered guilty of the destruction of natural resources - our true wealth - which affects the survival of the entire human race.

In not taking care of ourselves, we, as poor nations of the world, will fall victim to the pressure and action of the powerful countries who wish to impose their ways and policies upon our people. We must, therefore, dedicate specific efforts to the conservation of resources, specializing and dedicating our designated forest lands for this purpose.

It is urgent that we make our intentions and actions known internationally and that we counteract the information that discredits us. It is also urgent for us to speak up and let it be known that our countries demand that the planet - of which we are all a part - not continue to be polluted by the industrialized world.

It is urgent that we make known around the world that contributing to the survival of humankind demands personal sacrifices and significant financial obligations. It should be obvious that to maintain a national park, to protect an area and create a wildlife refuge, and, at the same time, to enact protection laws for the natural resources, costs a lot of money.

The rich nations cannot be indifferent towards this effort if they wish the human race to survive. Such countries need to contribute financially; they should help pay for that conservation.

We also need to contribute - by conserving our natural resources - for the well-being of mankind. The countries that have already destroyed their green resources should restore where they are able, conserve what little is left, and help pay so that the nations who still have them might maintain them.

It would be impossible to pretend that the rich purify their air, maintain the level of their oceans and moderate the temperature to which they are accustomed... all at the expense of the poor.

It is imperative to adopt a new attitude towards global justice. Let us, developing countries, provide of real wealth for the usufruct of all nations, demanding in return instruments that would facilitate our own development. This development is nothing else but the growth imposed upon us by the rich world of our time.

Population growth would not be such a problem if the riches of the earth were infinite. But our ecosystem is limited, and this presents an obstacle for the expansion of the human species. Obviously, the resources will not last forever and it is urgent to design new methods for their use, a design that needs to take into account the creativity of the new generations.

The resources which we usually exploit grow out of the evolution of the planet. Indiscriminate use by our generation can cause a very desperate situation for future generations. Although the known reserves will increase five times, a glimpse of total destruction can be seen on a short-term basis. Recognition of this danger should compel governments to be the keepers of natural resources. I feel the need to reenforce this concept and to extend it to the relationship between the human species and planet Earth... to put mankind in the perspective of guardian over its inheritance, which has been transmitted over and over for millions of years.

Let us make an effort so that the era of exorbitant consumption that we live in today will, in the future, be considered as a period of transition between the stable era of slow economy (past centuries) and a future recycled economy, which may again be stable and highly technological. This recycled economy will not be spontaneous. It will require research and development, as well as a considerable investment. Its development requires an adaptable philosophy that can be offered to all cultures, notwithstanding the actual basic premises as conditions for “a new way of life.”

The study of the earth's resources and the quality of life of the inhabitants of our planet must be considered integrally. We believe that an individual can live a healthy life in a pleasant environment; can maintain an active cultural life; and can have access to the beauty of nature. Quality of life constitutes mankind's enjoyment of satisfactory conditions, and the way to achieve that is through the satisfaction of his basic needs. It has been proven that a rich and diverse environment can guarantee the fulfillment of such needs.

The conceptual framework that has oriented the establishment and management of protected wildlife refuges in Latin America, and particularly in Costa Rica, has been guided by the principles defined by Kenton Miller (1980), for protected wildlife refuges planning. The objectives of these principles are:

· maintain large tracts of land as representative samples of the country's important biological regions in their unaltered state to assure continuity of the evolutionary process, including wildlife migration and genetic flow;

· maintain models of the various characteristics of all the types of natural habitat, physiographic form and landscape in order to protect the unique and representative diversity of the country, particularly to ensure the function of natural biodiversity in the regulation of the natural environment;

· maintain all genetic materials as elements of the natural habitat and prevent the extinction of species of plants and animals;

· provide the means and opportunities in the wildlife areas for formal or informal educational purposes, for investigation and for the study and regulation of the environment;

· maintain and operate watersheds in order to ensure the flow and purity of freshwater;

· control and prevent erosion and sedimentation, especially in those places related directly with the investments that will be made at the lower end of the river basins which depend on water for transportation, irrigation, agriculture, fishing and recreation; and for protection of the natural areas;

· maintain and operate fishing and wildlife resources for the production of proteins and as a base for industrial, sport and recreational activities, always taking into account the vital function that they play in regulating the environment;

· provide constructive and healthy opportunities for outdoor recreation for local residents and for visitors from the different parts of the country and abroad, in order to allow for tourist development based on the natural and cultural characteristics of the country;

· manage and improve the timber resources to fulfill their role in regulating the environment and providing a stable production of lumber products for the construction of homes and for other important uses within the country;

· protect and make objects, places and cultural, historic and archeological structures accessible for the purpose of public use and scientific research as elements of the country's cultural heritage;

· protect and manage the landscape to ensure the environmental quality near cities and towns, roads, rivers and recreational and tourist areas;

· maintain and manage extensive tracts of land under flexible methods of land use, in order to conserve the natural processes which ensure the freedom of options in case of future changes.

· sustainable use of the natural resources (water, land, forests, wildlife, etc.);

· conservation of the biodiversity (which includes the diversity of the species and the diversity of the ecosystems);

· maintenance of the essential ecologic processes and vital support systems such as recycling of nutrients, quality protection of water sources, as well as conservation and rehabilitation of soils;

· improve the quality of life by profiting from environmental, industrial, technological, administrative and legal opportunities that favor the sustainable use of natural resources, and yield environmental quality that offers greater options for satisfying basic, recreational, aesthetic and spiritual needs;

· achieve a more equitable balance between rural and urban development through strategic plans that promote an integral cultural and socio-economic development in the rural environment making it attractive, and at the same time, improving the quality of life of the marginal sectors in the urban environment;

· profit from the nation's non-renewable resources and the country's tourist potential, in order to contribute to a long-term sustainable economy for the benefit of the majority of its citizens and in harmony with the environment;

· define immigration and population policies with a long-term vision, considering the limitations of our basic natural resources;

· raise the citizens' consciousness towards issues that empower mankind - social justice, austerity, a healthy economy, high moral ethics in private and public functions; and the conservation and rational use of natural resources. These are essential to obtain long-term sustainable development and to prevent reduction in the quality of life that could jeopardize the country's civil peace and traditions;

· promote individual and collective responsibilities towards nature, environmental and economic stability, and human solidarity to ensure material progress and a greater harmony among humans, as well as between man and nature.

When dedicating a national park I always say, as President of the Costa Ricans, that we do it in order to fulfill our obligation before God and also as a contribution in benefit of all humanity.

I congratulate you for this extraordinary assembly and express my sincere wishes for the success of its deliberations. Thank you.

Text of Luncheon Address by Sandra Postel¹

Author of Last Oasis: Facing Water Scarcity

¹ Vice-President of Research, Worldwatch Institute, 1776 Massachussetts Avenue, NW, Washington, DC 20036-1904, USA. Telephone (202) 452-1999.

In many people's minds, the term “water scarcity” conjures up visions of drought - the impression that nature hasn't delivered what it was supposed to, and as a result, people end up short of water. But in fact the most disturbing signs of water scarcity are actually being caused more by human activities than by nature, and in many pans of the world, conditions of scarcity are rapidly becoming chronic.

There are now 26 countries that have more people than their water supplies can adequately support. This is based on a rule of thumb hydrologists use that countries need at least 1,000 cubic meters of water per person per year to meet food, industrial, household, and ecological needs. This 1000 cubic meters per year, which translates to about 725 gallons per person per day, is son of a minimum benchmark. When per capita supplies drop below this amount, a country is considered water scarce.

Africa currently has 11 water-scarce countries, the most of any continent. Given current rates of population growth, 4 others will join this list by the end of the nineties (Malawi, Morocco, South Africa, and Sudan), and the total number of Africans living in water-scarce countries will climb to 300 million - that's a third of the continent's projected population for the year 2000.

The Middle East is the most concentrated region of scarcity in the world today, with 9 out of 14 countries already in the water-scarce category. Tensions over water are high in all three of the Middle East's major river basins - the Jordan, the Nile, and the Tigris-Euphrates. The situation is particularly acute in the Jordan basin, which supplies Israel, Jordan, the West Bank, and part of Syria. Israel is already in a water deficit situation and about a third of its supply comes from sources within the occupied territories. So you can see how any ideas of trading land for peace are tightly linked to the issue of water security. Water scarcity issues will increasingly shape the political landscapes and economic futures of the countries in this region. It's my feeling that by the end of this decade, water problems will lead either to an unprecedented degree of cooperation in the Middle East, or a combustible level of conflict.

Besides this population-water equation, many physical signs of water scarcity are now evident around the world. Falling water tables from the overpumping of groundwater are now widespread in parts of China, India, Mexico, Thailand, the western United States, north Africa, and the Middle East. Water tables under Beijing, China's capital, for instance, have been dropping 1-2 meters per year.

We can point to whole economies that are now dependent on the mining of fossil groundwater - underground water reserves that are hundreds or even thousands of years old and which get very little replenishment from rainfall today. Saudi Arabia, for instance, is mining fossil groundwater to meet 75 percent of its current water needs. The Saudis use desalination for drinking water, but virtually the entire agricultural economy of the country is based on a groundwater supply that is projected to be depleted in less than 50 years. Clearly, the 4 million tons of wheat the Saudi's produce with this water are not a reliable part of the food supply.

We have a somewhat similar situation in the U.S. with the Ogallala aquifer in the Great Plains. Texas has depleted its portion of the Ogallala by a fourth, and irrigated area in the region is declining. In Northwest Texas, which overlies the Ogallala, irrigated area has fallen by a third since 1974.

In fact, when we look at irrigated area on a global basis, we now see a very disturbing trend. For most of modern history, the world's irrigated area grew faster than population did. This helped food production stay ahead of population growth. But in 1978, this trend turned around. Per capita irrigated land peaked that year, and it has dropped nearly 6 percent since then. Remember that irrigated lands give us a disproportionate share of our food - they make up only 16 percent of the world's cropland, but they account for a third of the global harvest. So this trend of declining irrigated land per person raises some red flags for food security. It's historically new, and, from my reading of things, our political leaders and policy makers have not yet fully grasped its consequences.

Finally, we also now see a host of ecological consequences from our overuse and mismanagement of water. As most of you well know, our basic approach has been to keep reaching out for more water and to gain ever more control over nature's water cycle. Global water use has more than tripled since 1950, and the answer to this rising demand has been to build more and bigger dams, river diversions, and other water supply projects.

The toll on the environment has been severe. We've heard quite a bit about some of the dramatic examples - like the Aral Sea in the central Asian republics, an ecosystem the size of Ireland virtually destroyed by excessive water use in the region.

Of course we have one of the premier examples in the world right here in south Florida. As we heard this morning, the Everglades are threatened by a range of activities that have greatly damaged the hydrological system that is the lifeblood of the Everglades. Only half of the original Everglades area remains. The population of nesting wading birds - herons, egrets, wood storks and so forth - has plummeted 90 percent since the 1930's.

Just about this time of year three years ago, I had the pleasure of seeing the Everglades system by helicopter thanks to the South Florida Water Management District. What I saw made a powerful impression on me - both the extraordinary beauty and wildness of the Everglades themselves, but also the relentless encroachment of more and more people and human activity into this fragile area. I couldn't help but think to myself afterward that if we in the United States, among the wealthiest countries in the world, should fail to save this treasure of an ecosystem, what realistic hope is there for wild places elsewhere - whether it's the Pantanal, the Sudd wetlands of Sudan, the Okavango Delta in Botswana, or the Donona wetlands in Spain - all of which are threatened by existing or planned water development projects.

There are many subtle signs of ecological damage as well. The American Fisheries Society, for instance, now lists 364 species of fish in North America as endangered, threatened, or of special concern - the vast majority of them at risk because of habitat destruction. Some of the prized salmon species in the western U.S. are on the brink of extinction. The winter run of Chinook salmon in California's Sacramento River, for example, has dropped from 120,000 in the sixties to just 400 today. And in 1992, just one adult Snake River Sockeye salmon made it to Redfish Lake, its primordial spawning ground in Idaho.

Putting water use on a sustainable footing and protecting the integrity of the aquatic environment is going to take, I think, a fundamental shift in our whole approach to managing water. Instead of constantly looking to expand the supply, as we've traditionally done for decades, the challenge is to focus much more directly on reducing our demand for water. We've been nibbling at the edges with conservation, but it can and should now be a centerpiece of water planning.

In most cases, measures to conserve and recycle water and to use it more efficiently are now the most cost-effective and environmentally sound ways of meeting water needs. Based on numerous examples, which I've documented in Last Oasis, it's safe to say that with technologies and methods already up and running, many farmers could cut their water demands by 10-50 percent, industries by 40-90 percent, and cities by a third. And these savings could be achieved cost-effectively. I'd like to quickly run through some examples.

Improving irrigation efficiency is a top priority, since agriculture accounts for two-thirds of global water use. Worldwide, irrigation efficiency averages less than 40 percent, so there's tremendous room for improvement. The savings possible in irrigation constitute a large, new supply. Just consider, for instance, that reducing irrigation needs by a tenth would free up enough water to roughly double domestic water use worldwide.

Technologies and methods that can do that and more already exist. Farmers in the Texas High Plains, where, as I mentioned the Ogallala aquifer is diminishing, have adapted their old-fashioned furrow irrigation systems to a new “surge” method that distributes water more uniformly and reduces waste. Their water savings have averaged 25 percent, and they've recouped their initial investment of about $30 per hectare within the first year.

We've seen expanding use of drip irrigation, a very efficient method that uses porous or perforated piping to deliver water directly to the crops' roots. It can achieve efficiencies as high as 95 percent. Worldwide, use of drip irrigation has expanded 28-fold since the mid-seventies, but it still accounts for less than 1 percent of world irrigated area.

In much of Asia, where there are very large canal systems, the challenge of increasing irrigation efficiency is as much an institutional one as a technical one. It's been estimated for instance, that in India, improving the infrastructure and operation of its large canal systems could allow the area under irrigation to expand by nearly a fifth without building any new dams.

The savings possible in industry are particularly striking. Pollution control laws have turned out to be terrific incentives to save water because they make it more economical to recycle water inside a factory than to release it to the environment. So in industry, more than any other sector, we've already seen some really big gains.

For instance, in 1965, Japan was getting $21 worth of output from each cubic meter of water supplied to industry; by 1989, it was getting $77 worth of output from each cubic meter supplied to industry - and that's in real terms (adjusted for inflation). So Japan's industrial water productivity more than tripled in just over two decades. Some of this, of course, is due to some shifting away from heavy industry, but much of it is due to greatly increased recycling rates in the major water-using industries like chemicals, iron & steel, and pulp & paper manufacturing. We see similar trends when we look at Germany and the U.S.

Here, again, I would add that we've seen just the tip of the iceberg. In California, the recent 6-year drought pushed industries to go well beyond the usual level of conservation and recycling out of fear that their supplies could get cut back. And so what we've seen in California are some really impressive reductions in water use among a wide range of industries. For instance, one study of a number of companies in the San Jose area - including IBM, Hewlett Packard, and Tandem Computers - showed savings of 30 percent all the way up to 90 percent, and with paybacks of less than a year in nearly every case.

Municipalities - cities, suburbs, and towns - account for less than a tenth of the world's water use, but their demands are concentrated geographically and so they put a lot of strain on local water bodies. And, as we all know, it takes a lot of money to build, operate, and maintain a modern water and wastewater system.

There are a number of cities around the world now that have made conservation an integral part of long-term water planning. We'll be hearing about Winnipeg's efforts later this morning. In my book, I talk about Boston, Jerusalem, Singapore, Los Angeles, Mexico City, and Waterloo, Canada as being among the metropolitan areas that have benefited from investing in conservation instead of the usual approach of expanding supplies. I found Boston's program particularly impressive. It was planned and implemented by the Massachusetts Water Resources Authority and through a combination of measures - including retrofitting residences, industrial water audits, and finding and fixing leaks in the distribution network - the program cut total water demand in the greater Boston area by about 20 percent in about 5 years. That brought water use back to the level of the late sixties, which has allowed the city to put off building an expensive and environmentally damaging new water project. And, again, the program was very cost-effective. Meeting water needs through conservation cost half as much as it would have to build a new river diversion project.

We'll be hearing more about conservation efforts in all these areas - agriculture, industry, and cities-during this conference. The key to bringing about these savings is replacing policies that promote profligacy and waste with ones that promote conservation and efficiency. In most countries, for instance, farmers pay less than 15 percent of the true cost of their irrigation water. That's been true of federal projects in the United States as well as in Mexico, Indonesia, Pakistan, and Egypt. Obviously new irrigation technologies are not going to spread as long as water is priced so cheaply.

It's my feeling that pricing, marketing, and regulations all have a role to play in bringing about sustainable water use. Which turns out to be the best and most appropriate policy instrument will vary, I think, from case to case. The thing we most need now is leadership - We need governments at the federal, state, provincial, and local levels to start making conservation a top priority and to start putting in place those policies that will enable the water efficiency revolution to unfold. The United States has taken a couple of important steps in this direction. In late 1992, a law was enacted that overhauls the Central Valley Project in California. This is the huge federal project that supplies irrigation water to 3 million acres in the agricultural heartland of California. Among other things, it calls for the establishment of a tiered pricing system that charges more for high levels of consumption, which should encourage farmers to conserve. It also allows Central Valley farmers to sell water to other water users in the state, including cities. And, finally, the new law dedicates 800,000 acre-feet of water each year to the aquatic environment. This water comes off the top of the project's deliveries, which means that rivers, wetlands, and fisheries will be assured a minimum amount of water even in times of drought. This is a pathbreaking new law that I hope will set a precedent for broader reforms in the western U.S. and elsewhere. And you can see that it combines the three major policy instruments - pricing, marketing, and regulations - to promote more sustainable water use overall.

In the area of urban conservation, we've seen strong moves in recent years toward the establishment of efficiency standards for common plumbing fixtures. In Canada, Ontario has adopted province-wide efficiency standards to help meet its goal of zero growth in water use for the next 20 years. Mexico was one of the first countries to adopt national standards, in part to help deal with the intractable water problems of Mexico City. And in late 1992, the U.S. established national efficiency standards as well. They are supposed to take effect in January 1994-though the federal government has been slow in coming up with regulations to enforce the law. These standards are important, since they will gradually cut indoor water use by 30 percent, helping lower water and wastewater costs nationwide.

Regulations also have an important role to play in the protection of watersheds and groundwater recharge zones. Careful land-use planning and zoning is about the only way I know of to ensure that land development does not destroy the integrity of the natural water system. A county on Long Island, New York, recently acquired 3,400 hectares of open space in order to preclude any development in a critical groundwater recharge zone. The county is paying for the land by way of a quarter-cent increase in the county sales tax, which was approved by the voters.

These policy tools cannot be fully effective, however, without education. It was Baba Dioum, a Senegalese conservationist, who said, “In the end we will conserve only what we love, we will love only what we understand, and we will understand only what we are taught.”

Historically, we have been quick to assume rights to use water, but slow to recognize obligations to preserve and protect it. What we need now, I think, is a new water ethic-one that makes the protection of water ecosystems a central goal in all that we do. We've heard it so often that it begins to sound trite, but water is, after all, the basis of life, and our stewardship of it will determine not only the quality but the staying power of human societies.

As I see it, the challenge now is to put as much human ingenuity into learning to live in balance with water, as we have put historically into controlling and manipulating it. And in the end, the time available to make this shift may prove as precious as water itself.

Thank you for your attention.

The Role of Environmental Education in Watershed Management

John H. Baldwin¹

¹ President, North American Association for Environmental Education, University of Oregon, 130 Hendricks Hall, Eugene, OR 97403, USA.

Alicia Barcena, the Executive Director of the Earth Council of Costa Rica, previously stated that, “the key to action is access to information.” She is referring to information that is accurate, appropriate, in the local language, in the right place and to a receptive audience. To foster change in water management policy, new and improved education and information systems are necessary. In closing, the development of new Inter-American Water Management Policy involves a fundamental change in development thinking. Modern systems of education and information are needed to inform the public to foster community and regional support for water management projects. Education is a strong proponent of change. It is through change that real progress will be made in water resource management. H.G. Wells expressed my sentiments years ago by stating: Civilization is a race between education and disaster. Thank you.

Water Resources as Eyewitness to the Health and Future of the Planet

Charles R. Goldman¹

¹ Professor of Limnology, Institute of Ecology, University of California, Davis, California 95616, USA

At no time in our relatively short history on earth has the value of maintaining adequate clean water supplies for agriculture, industry, and domestic consumption been more important to the earth's rapidly increasing human population. Demographic predictions are that ninety-five percent of this growth will occur in the southern hemisphere. The importance of water restoration projects ranging from improved erosion control to lake, river and wetland management, rehabilitation, and pollution control can scarcely be over emphasized. In fact, the quality of life in many pans of the world is already seriously impacted by inadequate quantity and/or quality of available water. The droughts in the west and recent floods in the Midwest and Europe and hurricanes all serve as painful reminders of the power of climatic forces. It has become increasingly evident that we need to maintain the more natural order of entire watersheds and their associated wetlands to reduce the damage of these events.

This conference includes reports on restoration and conservation planning for the enormous 140,000 km² Pantanal in the upper Paraguay River Basin in western Brazil, eastern Bolivia, and northeastern Paraguay, the Florida Everglades, the Upper St. John's River Basin, as well as the Upper Mississippi. Although these projects are individually very different, they have the common objective of providing for multiple water use while at the same time rehabilitating river and wetland systems damaged by water diversion, development or pollution. Since important human, plant, and animal populations will all ultimately be affected by the design, execution and performance of these costly projects they are of great importance to this and future generations.

Lake Tahoe, USA, for more than thirty years has been a microcosm for the study and resolution of environmental conflict. Lessons from the Tahoe consensus building are already being exported to Lake Baikal in Russian Siberia. This is the world's oldest and deepest lake soon to be designated as an International Heritage Site by UNESCO. Research on environmental conditions in Tahoe, Honduras, Costa Rica, Ecuador, Brazil, Argentina, and Africa will highlight the importance of understanding ecosystem structure and function for management. It is important to monitor the impacts of existing conditions and have an adequately flexible long-term research program to take advantage of new knowledge and technology. Only then can we move beyond the conflict, and through active consensus building avoid endless litigation while the values of the resource continues to decline.

Hydrometeorological Advances in Flood Forecasting in View of Lessons Learned from The Great Mississippi Basin Flood of 1993

Michael D. Hudlow¹

¹ Director, Office of Hydrology, National Weather Service, NOAA, 1325 East-West Highway, Silver Spring, Maryland 20910, USA

The Great Flood of 1993 was a hydrometeorological event without precedent since the United States started providing weather services over a century ago. In terms of precipitation amounts, record river stages, areal extent of flooding, persons displaced, crop and property damages, and flood duration, this event surpassed all floods in the United States during modern times. There were 500 counties in nine states devastated by The Great Flood of 1993. Record and near-record precipitation in the spring of 1993 on soil saturated from previous seasonal precipitation resulted in flooding along many river systems and their tributaries. Figure 1 shows the general area impacted by heavy rainfall and flooding.

In the Mississippi and Missouri River main stem systems alone, a total of 93 record river stages were broken. The duration of The Great Flood of 1993 was as overwhelming as the areal extent of flooding and the number of new record stages established.

ANTECEDENT CONDITIONS

The hydrological and meteorological conditions that lead to the flood were unique, complex, and extreme in many respects. An extended wet period in the fall of 1992 moistened soils to near saturation and raised many stream levels to bankfull or flood levels. This set the stage for rapid runoff and record flooding that followed excessive June and July rainfall.

During The Great Flood of 1993, a persistent atmospheric pattern produced excessive rainfall across much of the upper Mississippi River Valley and the northern and central Great Plains during June, July, and the first half of August 1993. Much of the major river flooding originated from several synoptic scale copious rainfall events from mid-June through late July. During the summer (June-August 1993), rainfall totals surpassed 12 inches across the eastern Dakotas, southern Minnesota, eastern Nebraska, and most of Wisconsin, Kansas, Iowa, Missouri, Illinois, and Indiana. Over 24 inches of rain fell on central and northeastern Kansas, northern and central Missouri, most of Iowa, southern Minnesota, and southeastern Nebraska, with up to 38.4 inches in east-central Iowa. These amounts were approximately 200-350 percent of normal from the northern plains southeastward into the central Corn Belt. Since the start of the growing season (April 1), precipitation amounts through August 31 were even more impressive: totals approached 48 inches in east-central Iowa, easily surpassing the area's normal annual precipitation of 30-36 inches. (From a seasonal standpoint, above- to much above-average rainfall fell over the entire Upper Midwest from May through August 1993. The May-August 1993 rainfall amount is unmatched in the historical records of the central United States.) In July, there were broad areas in North Dakota, Kansas, and Nebraska, as well as a smaller pocket in Iowa, that experienced over four times normal precipitation. The April-July precipitation amounts are remarkable not only in magnitude but also in their broad regional extent. Record wetness existed over 260,000 square miles. The Missouri July values were somewhat tempered by below-normal rainfall in the extreme south, although some areas of northwestern Missouri had over 30 inches of rain in July alone. Seasonal rainfall records were shattered in the affected areas.

HYDROLOGIC ANALYSIS

Extreme flooding of major river systems, like the Mississippi and Missouri Rivers, typically does not occur in the summer because of the highly variable nature (in space and time) of convective rainfall in the Midwest coupled with high rates of evapotranspiration. Typical midwestern summers experience a few localized heavy rains of as much as 6-12 inches in 1-2 days that extend over a few thousand square miles. These heavy rains are usually found randomly distributed, producing localized flash floods on streams and tributaries, but are not usually sufficient to produce major flooding on larger river systems of any consequence.

Figure 1

Another common aspect of the precipitation climate of the midwestern summer involves atmospheric conditions capable of producing above-average rainfall over sizable (state-scale) areas in random parts of the Midwest. When these conditions do not occur, the Midwest has summer droughts like that of 1988. These “wet periods” typically persist for 2-5 weeks and sometimes last up to 8 weeks creating the “wet summers” found in the climatic record. However, excessively heavy rain extending over wide multi-state areas and lasting more than 8 weeks is a rare event. These long-lasting and spatially extensive wet conditions, along with exceptionally wet antecedent hydrologic conditions, were necessary hydrometeorological conditions required to produce the massive flooding in the Midwest during the summer of 1993.

HUMAN AND ECONOMIC FACTORS

When measured in terms of economic and human impacts. The Great Flood of 1993 clear will be recorded in twentieth century history as this Nation's most devastating flood. Initial assessments of the economic impact of The Great Flood of 1993 indicate that losses will range between $15-20 billion. This will rival Hurricane Andrew in overall losses.

During The Great Flood of 1993, the Missouri Basin River Forecast Center (MBRFC) and the North Central River Forecast Center (NCRFC) were the two offices within the nine-state area impacted that were responsible for the preparation of the river forecasts. During normal operations, the MBRFC and NCRFC basically operate day-time schedules during the week and provide an on-call coverage during the night hours with only skeleton service on weekends. Naturally, when a “normal” flood event does occur, the hours of operation at the RFCs are extended to meet the needs of the occasion. Around-the-clock operations do occur but usually only for a day or two. Within days, or even a week in some unusual instances, the RFC reverts to its normal hours of operation.

Not enough can be said about the quality of the performance of the National Weather Service (NWS) employees during The Great Flood of 1993. The extraordinary effort exerted under extremely stressful conditions, which persisted for literally months, is unprecedented. The devotion to quality services and protection of life and property was extraordinary. The human judgment and expertise in many cases compensated for serious deficiencies in the current capabilities of the forecast and warning system. The services provided during this historical event were a major team effort by 2 RFCs, 9 Weather Service Forecast Offices, and 20 Weather Service Offices with support from national centers. This team effort was momentous, and the collaborative effort by all offices was outstanding.

ADVANCED HYDROLOGIC PREDICTION SYSTEM

It is clear that in view of the magnitude of the losses, every effort must be taken to reduce potential future losses. It is also clear that many questions raised during the flood were similar to questions raised during the 1988 drought. For example, “When will barge traffic resume?” and “When will this flood/drought end?”

Many lessons have already been learned from The Great Flood of 1993. Foremost among these is the need to accelerate the implementation of an Advanced Hydrologic Prediction System (AHPS). The major components of this advanced prediction system are as follows (see Figure 2):

1. Current River Forecast System (NWSRFS) operational foundation;
2. National Oceanic and Atmospheric Administration (NOAA) partnerships;
3. NWS modernization technologies;
4. Advanced Water Resources Forecasting System (WARFS) capabilities.

Figure 2

The first component of the AHPS is the NWSRFS. It is the mainline river forecast system of the United States NWS. This computerized system was developed through a team effort by the Office of Hydrology at the national level and the RFCs at the field level. Development of the system has evolved to the current Version V which has been implemented at RFCs across the United States. The NWSRFS allows for the automated input of data from a number of sources and provides maximum flexibility to the forecaster in selecting and using the procedures that will do the best job for a specific river basin. The system also provides the opportunity for each RFC to include its own unique procedures and allows other offices to use them. With the NWSRFS on-line, the RFCs will be able to effectively implement the latest technology in a timely manner as it becomes available.

The second component is NOAA's partnerships. The NWS regularly interacts with its many partners in data and information exchange. Partners include Federal agencies (Corps of Engineers, Geological Survey, and Soil Conservation Service), Regional Commission (Salt River Project, Denver Water), the private sector, universities, and state and local agencies involved with hydrological and water resources. The AHPS is geared to decision making for flood preparation and management. During The Great Flood of 1993, these partnerships proved invaluable.

The third AHPS component is NWS modernization technologies which involves new sources of information about the atmosphere, powerful new information and processing systems, reconstruction of NWS into an interactive scientific work station environment, and a new organizational structure. The overriding goal of the modernization is to improve the quality and reliability of NOAA services.

Implementation of the major NWS modernization technologies, principally the Next Generation Weather Radar (NEXRAD) and the Advanced Weather Information Processing System (AWIPS), will (1) substantially improve the availability of higher resolution meteorological and hydrological data and information, especially radar-based precipitation estimates, and (2) provide powerful interactive-processing capabilities. The modernization technologies allow forecast operations to be better tailored to each RFC's needs.

WARFS, the fourth AHPS component, is essential for major advances required to provide an improved national hydrologic prediction system for floods and droughts; for operations on large lakes; and for better overall water management through advanced hydrologic/hydraulic modeling, improved data integration techniques, enhanced real-time and historical databases and optimal incorporation of meteorological and climate forecast information (see Figure 3). During crises, WARFS will greatly improve the Nation's capability to take timely and effective actions that will significantly mitigate the impact of major flood and drought situations.

Figure 3

LESSONS LEARNED DURING THE GREAT FLOOD OF 1993

A NOAA disaster survey team was formed to identify opportunities to improve NOAA's weather and flood forecast and warning systems, not only for the effected region but also throughout the Nation. Those improvements to NOAA's environmental prediction capabilities will: (1) advance the agency's overall contributions to environmental services; (2) expand the payback on current investments, and improve and/or extend the benefits to many more segments of the public. An enhanced, modernized hydrologic forecast and warning system will help:

1. Reduce fatalities and injuries due to hazards from weather and floods;

2. Improve the flow of more accurate environmental data and predictions to the public;

3. Enhance the ability of planners to use hydrologic forecasts in the range of days to months;

4. Provide better information for management of fresh water resources;

5. Prevent avoidable damage to private, public, and industrial property over land, in coastal areas, and along rivers; and

6. Improve efficiency, reliability, and savings in industry, transportation, agriculture, and hydro-energy systems.

Although The Great Flood of 1993 has caused devastating human, environmental, and economic impacts, the lessons learned will guide us in providing improved services and benefits to the Nation in the future.