2007 Watershed Expeditions


The Columbia River, 1,243 miles long, is North America’s 4th largest river by volume. Its watershed, larger than France, spans parts of 1 Canadian province, 7 U.S. states and 11 tribal nations. Over 11 million people rely on the river for livelihood and recreation, yet it is threatened by climate change, infrastructure, pollution and resource extraction. Receding glaciers and diminishing snow pack are reducing water supply. Infrastructure, including over 400 dams, impacts habitat, impedes fish migration and restricts traditional uses of the river. Waste from industry, a nuclear site, mines and agriculture threaten water quality and aquatic habitat. Over- extraction of timber, water and fish weakens the economic and environmental sustainability of the watershed and strains relations between Canada, the U.S., and Tribal Nations. Fortunately, concern has generated many public and private efforts to foster sustainable resource management: dams are being re-evaluated and a new Basin Treaty in 2014 could be a positive model for responsible joint management of a shared resource.


The Omo River, flowing 621 miles from Ethiopia’s Highlands to Kenya’s Lake Turkana, creates an inland drainage basin of 56,371 square miles. It is prone to severe droughts that cause widespread famine and political turmoil. The health of the basin’s population, largely indigenous tribal cultures, suffers from lack of clean fresh water for human and livestock consumption, sanitation and washing. Recent heavy flooding, connected with climate change, has caused community dislocation. Overgrazing of livestock and removal of vegetation (providing fuel and open fields for crops) has added heavy sediment loads into the Omo. Small irrigation projects have contributed to a 50% reduction of the Omo River’s discharge into Lake Turkana.

Upstream dams, a new highway crossing the Omo River from Sudan to Kenya and large-scale irrigation may create food security and offer flood control and hydroelectric power. Proposed storage and marketing facilities, as well as new roads for water and food distribution would alleviate many problems of rain-dependent subsistence agriculture, which keeps nearly half of the Ethiopian population in poverty and without food. However, environmental consequences of such projects may include increased immigration of foreign populations and over-extraction of the Omo’s freshwater resource, negatively impacting basin cultures and ecosystems.


The Nile, the world’s longest river, exemplifies the challenges of trans-boundary watershed management. Half the estimated 160 million people in this arid basin, spanning one tenth of Africa, depend on the Nile for survival; yet river overuse threatens further desertification. The Blue Nile, supplying 86% of the Nile’s water, flows from Lake Tana (Ethiopia) to Khartoum (Sudan), where it joins the White Nile. Climate change is predicted to shorten wet seasons, increase precipitation and intensify dry periods in the Blue Nile Basin, which already faces chronic drought and deforestation. High sediment loads from increased deforestation and agriculture have severe environmental consequences; and poor sanitation creates dangerous health issues.

The 1959 Nile Waters Treaty grants usage of 87% of the Nile’s fresh water to Egypt and 13% to Sudan – but no water rights are granted to Ethiopia, even though its first 1,529 miles are in that country. Lack of irrigation rights greatly reduces Ethiopia’s agricultural output, contributing to a dependence on food aid by 2 million Ethiopians. Yet, downstream, the Nile sustains crops in Egypt’s deserts for export. Growing populations throughout the basin’s ten countries are all demanding access to more water. President Anwar Sadat said in 1979, “The only matter that could take Egypt to war again is water.”