Virginia Capes Range Complex Final Environmental Impact Statement

VACAPES Range Complex FEIS/OEISChesapeake BayChapter 3 Affected Environment andEnvironmental Consequences3.3 – Water ResourcesThe Chesapeake Bay Program is a regional partnership that directs and conducts restoration of theChesapeake Bay (Chesapeake Bay Program, 2007). Chesapeake 2000 is the most recent agreement bythe partners in the Chesapeake Bay Program and is intended to guide restoration activities throughout theBay watershed through 2010.The Chesapeake Bay is the largest of 130 estuaries in the United States, with a watershed that includesparts of six states (Delaware, Maryland, New York, Pennsylvania, Virginia, and West Virginia) and all ofthe District of Columbia (Chesapeake Bay Program, 2007). The Bay is about 200 miles long, stretchingfrom Havre de Grace, Maryland to Norfolk, Virginia (Figure 3.3-2). The Bay’s width ranges from3.4 miles near Aberdeen, Maryland, to 35 miles near the mouth of the Potomac River. The Bay receivesabout half of its water volume from the Atlantic Ocean; the rest drains into the Bay from a 64,000 squaremile drainage basin or watershed.The Chesapeake Bay holds more than 18 trillion gallons of water. There are approximately 150 majorrivers and streams in the Chesapeake drainage basin (Chesapeake Bay Program, 2007). The SusquehannaRiver in south central Pennsylvania provides about 50 percent of the freshwater coming into the Bay - anaverage of 19 million gallons of water per minute. The water in the Chesapeake Bay is shallow; althoughthe Bay covers a large surface area, its average depth, including all tidal tributaries, is about 21 feet. TheBay’s salinity ranges from freshwater (0-0.5 ppt) near the Susquehanna River to water of nearly oceanicsalinity (30-35 ppt) at the mouth of the Bay. The Bay has two of the five major North Atlantic ports inthe United States, including Baltimore and Hampton Roads.Water Quality in the Chesapeake Bay is influenced by natural conditions as well as anthropogenicsources. The weather plays a large role in conditions in the Bay and a typical year is as follows. Rain inthe spring washes pollutant loads into the Bay, and lowers salinities to the minimum for the year.Summer weather plays a role as surface water temperature increases with air temperature increases.Salinity rises during the summer due to less rainfall and increased evaporation, and stratification occursbetween surface and bottom water. Dissolved Oxygen (DO) levels are also at their lowest (often anoxic),especially in the deeper tributaries such as the Potomac and Baltimore Harbor. Fall brings aboutimproved water clarity, decreased water temperature and increased salinity. Due to colder temperaturesin winter, the water is well mixed, which causes temperature, salinity and oxygen levels to be similarthroughout the water column. DO levels are at also their highest during the winter; however, biologicalactivity is reduced (Maryland DNR, 2007).The Chesapeake Bay was listed as an impaired water body under the Clean Water Act (CWA) due toexcess nutrients and sediment (USGS, 2007). Improvements in water quality conditions must be made by2010, or regulatory approaches to achieve these standards will be implemented. A summary the keywater quality issues in the Chesapeake Bay is presented below.Summary of Key Water Quality Issues in the Chesapeake BayThe February 2004 Biennial Report of The Secretary of Natural Resources to The Virginia GeneralAssembly (Virginia Secretary of Natural Resources, 2004) summarized several key water quality issues inthe Chesapeake Bay, including excessive levels of nutrients and their impact on living resources andimpacts from toxic chemicals in regions with existing or potential problems. The following discussion oftrends is specific to the Chesapeake Bay and its tributaries.3-49 March 2009