"the window of opportunity to resrve the trend in declining water resources is closing because of the extent of the loss of watershed processes upon which those resources depend." - Dr. James Karr, Director, Institute for Environmental Studies, Seattle, Washington

THE MERRIMACK RIVER WATERSHED

The Merrimack River is formed by the confluence of the Pemigewassett and Winnepesaukee Rivers in Franklin, New Hampshire. It flows south through New Hampshire's capital, Concord, past its most populated cities of Manchester and Nashua and into Massachusetts, where it turns sharply east toward the Atlantic and flows through the cities of Lowell, Lawrence, and Haverhill. With the fourth largest basin in New England, covering 5,010 square miles, the river is the drinking water source for several Massachusetts and New Hampshire communities, supplying more than 237,000 people in Massachusetts alone. Approximately 1,484,000 people lived in the basin in 1980.

A long history of economic dependence on manufacturing and service industries throughout the basin resulted in severe degradation of this important water resource. In the 1930s, contamination along the length of the river made it too polluted for domestic water supply uses. Raw sewage from the towns and communities located along the riverbanks, paper mill waste, tannery sludge, and other pollutants had been dumped into the river untreated over a long period of time. By the end of World War II, the Merrimack was recognized as one of the 10 most polluted rivers in the nation because of human use of this river as a waste stream.

Today, governmental agencies and citizen groups in the watershed are working to address the issues affecting river life and water quality. For example, the Merrimack River Watershed Council, an interstate organization dedicated to the protection of the Merrimack River, is building a citizenry alert to the issues and establishing coalitions to protect and restore the river.

THE SOUTH PLATTE RIVER WATERSHED

The South Platte River originates in the mountainous region of central Colorado at altitudes greater than 14,000 feet above sea level and flows generally eastward for 270 miles through the populous Front Range urban corridor and across Colorado's eastern plains. The South Platte continues into Nebraska, where it joins with the North Platte to form the Platte River, which then flows into the Missouri River. A number of tributaries join the South Platte as it flows north- and eastward toward the plains. The total area of the entire South Platte River basin covers 23,900 square miles.

Severe water quality problems in the upper reaches of the South Platte and its tributaries are the result of the mining of rich deposits of ores since 1859. Loadings of metals, including zinc, copper, and manganese, from the large number of active and abandoned mining sites contribute to chronic toxicity problems in certain tributaries to the South Platte, suppressing the number and size of fish that can thrive in that environment. Some upstream tributaries in the South Platte basin are altogether devoid of fish populations as a result of acid mine drainage. Further downstream, around the Denver metropolitan area, human impact is significant because of the high residential, working, and vacationing populations within the basin. After the South Platte leaves this urbanized area, the primary impacts on the river are related to agricultural activities. Application of fertilizers, pesticides, and herbicides are all sources of water quality degradation affecting both surface water sources and ground water reserves. In addition, although precipitation rates are low in this region, erosion is a significant problem in many areas. Impacts of degraded water quality on fish throughout the watershed range from reported fish kills on specific tributaries to restrictions on fishing and reduced distribution of fishery habitat for many species.

Communities in the South Platte watershed are now taking action to improve the quality of the river. For example, the Denver metropolitan wastewater authority has significantly reduced the toxicity of its wastewater by removing toxic pollutants, to the benefit of downstream waters.

THE SAN FRANCISCO BAY WATERSHED

The Sacramento and San Joaquin river watersheds drain California's Central Valley -- 40 percent of the State's land area -- into San Francisco Bay, emptying into an approximately 1,200-square-mile marsh region. Since the mid-nineteenth century, one-third of the bay has been converted to dry land by filling, 90 percent of the bay's wetlands has been destroyed, and more than 60 percent of its freshwater inflow has been diverted, mainly for irrigation.

So productive were the bay's fisheries in 1875 that the bay region supplied 93 percent of the State's commercial fishery products. By 1950, the entire fishery was almost depleted. A similar story may be told of the waterfowl, shorebirds, and game that once abounded in the region. As a result of gold mining and flood protection, extensive levees throughout the delta eventually excluded tides and floodwaters from 90 percent of the marsh, vastly changing its physical character, vegetation, and fauna. Nineteenth-century hydraulic mining in the drainage areas of the rivers deposited tens of millions of cubic meters of earth and rock into the bay. This reduced its depth and changed its shape and circulatory patterns. In addition, dams above the delta blocked fish from their spawning grounds upriver and reduced the freshwater inflow to less than 40 percent of historic totals, thus contributing to the demise of bay fisheries. These problems have been compounded by massive discharges of agricultural wastewater, much of it containing contaminants and toxic elements from fertilizers and pesticides. Untreated urban runoff, containing substantial quantities of oil and grease washed by rain through storm drains into the bay, and spills of industrial chemicals add further to the stress on the estuarine ecosystem.

Recognizing the severe degradation of the Bay's resources, San Francisco Bay was designated an estuary of national significance in 1987. A comprehensive management plan has been developed, and partnership efforts are underway to restore the Bay and its watershed.

Go to Section III: Back to Basins: Using Nature As Our Guide

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