A Status Report on Calvert’s Environmental Resources and Issues
By Dr. Walter Boynton
Introduction and Purpose:
Calvert County is endowed with an amazing abundance and diversity of natural resources. Chesapeake Bay, often thought of as the queen of North American estuaries, borders the County to the east and the Patuxent River estuary, the largest river-estuary wholly within Maryland, defines the western border of the County. There are approximately 101 miles of shoreline in Calvert County, a resource of very considerable value. Additionally, extensive and productive tidal and non-tidal wetlands and freshwater streams connect the land to the open waters of the estuaries. Productive farmland and forests also cover significant areas of the county.
The purpose of this section of the Sustainable Calvert White Paper includes the following: 1) provide facts and trends concerning County natural resources; 2) identify places where additional and more detailed information can be found; and 3) indicate issues of concern, both positive and negative.
The total County land area is about 220 square miles; the County is 30 miles in length and about 9 miles wide at its widest point. Calvert, in terms of land area, is the smallest of the 23 Maryland Counties.
Land use has great influence on environmental conditions both on the land and in the adjacent streams, wetlands and estuaries. There is considerable historical information available concerning changes in County land uses. For example, paleoecologists found that prior to European settlement in the early 1600s the land was almost completely forested with a mixture of deciduous hardwood and some evergreen species. This condition changed a great deal during the next several hundred years and by 1850 only 14% of the Patuxent River basin remained forested and it seems likely that the same was true for Calvert County. The remaining 85% of the land was either in active agriculture or fallow following agricultural activities. A great deal of farmland was abandoned following the Civil War and forest re-growth began. By the early 1950s almost 40% of the Patuxent Basin was forested and by the early 1970s that had increased to almost 60%. Since the mid-1980s forest cover has slowly decreased, as has agricultural lands; urban and residential land uses have increased.
Land uses in Calvert County have also changed in more recent times. During the mid-1970s forested, residential and agricultural lands covered 54, 11, and 35% of the County. By 2007 these uses had shifted with forested, residential and agricultural lands then covering 47, 37, and 13% of the land area, respectively. Agricultural and forested land uses declined markedly and residential/urban/commercial increased.
There are ecological consequences associated with changing land uses. For example, expansion of urban and residential land uses generally increases impervious surfaces that, in turn, lead to increased storm water runoff, soil erosion, stream habitat degradation and increased nutrient and sediment loads to tidal waters of the Bay and Patuxent River. It is a serious challenge to counteract the negative ecological effects of land conversion to urban/residential uses. The challenge and cost of both prevention and remediation should not be underestimated.
On a positive note the County currently has considerable areas of open space, but less than recommended by State of Maryland guidelines (XX acres of open space per resident). There are five major County Parks (King’s Landing, Dunkirk Park, Hallowing Point, Cove Point Park, the Cypress Swamp and Flag Ponds) and the State-owned Calvert Cliffs Park. In addition there are five land trusts in the county and together they own 2000-3000 acres of land. Calvert County, with five land trusts, is tied with Baltimore County as having the most land trusts of any County in the State. There is an active farm preservation effort on-going in the County where about 29,000 acres of farmland have been preserved with a goal of 40,000 acres (28% of County land area).
Streams of Calvert County:
There are about two dozen large and many more small streams originating in Calvert County with the majority of these larger streams (18) draining into the Patuxent River. Some of the larger Bayside streams include Parkers Creek and Fishing Creek. Well-known Patuxent River streams include Lyons, Hunting, Battle and St. Leonard Creeks. Overall, there are about 12,000 miles of streams in Maryland and about 200 miles of non-tidal creeks in Calvert County. In addition to these named creeks there are many more smaller, often intermittent, streams in the County. The net result is that all county residents and businesses are intimately connected, via water flows from both large and small streams, to the tidal waters of the Chesapeake Bay and Patuxent River. So what each of us puts on and does to the landscape can eventually end up in the Bay.
These streams, even the smallest, serve important and often overlooked ecological functions in addition to their aesthetic value. They are home to many freshwater fishes and countless
species of invertebrates (e.g., insect larvae, crayfish) that anchor the aquatic food web. They serve as spawning places for migratory fish, some of which form important links in the food webs leading to commercially and recreationally important specie Streams provide many recreational opportunities, a use that appears to be growing rapidly. Importantly, these streams and associated tidal and non-tidal wetlands clean the water by removing excess nutrients, absorbing pollutants, and trapping sediments—functions essential for restoring the Bay and Patuxent River.
So what do we know about the health of Calvert County streams? Maryland is fortunate to have a statewide monitoring program that measures the water and habitat quality and also assesses the biological integrity of non-tidal streams, including streams in Calvert County. Conducted by staff from the Department of Natural Resources (DNR) and the University of Maryland’s Appalachian Lab, the Maryland Biological Stream Survey completes a statewide assessment every 4-5 years. The third and most recent stream health assessment was completed in 2009. The fourth statewide survey began in 2014 and will be completed in 2018. About 10 stream sites will be sampled in Calvert County in 2017 and 2018.
Since it began in 1995, the Maryland Biological Stream Survey has sampled and assessed the health of 38 streams in Calvert County. Of these monitored streams, 19% were found to be in good condition (based on the composition of fish and macroinvertebrate assemblages), 25% were in fair condition, and over half (56%) were in poor to very poor condition. Between 2000 and 2012, volunteer citizen scientists trained by DNR staff collected macroinvertebrates from 76 stream sites in the County. Their findings were similar to those of the Maryland Biological Stream Survey: more streams were in poor to very poor condition than fair or good.
These monitoring results indicate we need to do a better job concerning stream health. For starters, those county streams that are still in good condition (e.g., Lyons Creek, Plum Point Creek, Hall Creek) should be protected from degradation. One of the major threats to stream health is adding more impervious surfaces to the landscape that decreases the infiltration of stormwater and increases runoff and stream channel erosion. For those streams that are already degraded, prudent remediation actions include reducing pollutants at the source and maintaining or enlarging streamside forest buffers. More aggressive and expensive actions include re-connecting streams to their flood plains and adding pools and other water-holding structures to the stream. There is some serious work needed to improve the quality of Calvert County streams.
More information concerning streams and stream monitoring/assessment results in Maryland and Calvert County can be found at http://dnr2.maryland.gov/streams/Pages/mbss.aspx
In sharp contrast with some other portions of the State and region, residents of Calvert County use groundwater as a source of potable water. There are no drinkable surface water resources in the County.
The United States Geological Survey (USGS) along with the Maryland Geological Survey and the Calvert County Department of Public Works conducts assessments of groundwater supplies for Calvert County using a network of 42 monitoring wells that are influenced by regional and local water withdrawals. In brief, there are several aquifers underlying Calvert County from which most water is withdrawn and these include (in order of depth below the surface) Piney Point-Nanjemoy (limited current use), Aquia (main public water source), Magothy and Upper and Lower Patapsco. Test data from monitoring wells indicate several cones of depression in the vicinity of North and Chesapeake Beach and Solomons, indicating local aquifer water withdrawals in excess of recharge. However, water supply estimates based on test well data indicate adequate water supplies through the mid-21st century. Additional information concerning groundwater resources can be found at www.co.cal.md.us/DocumentCenter/View/8674 and www.mgs.md.gov/wss/.
Air Quality in the County:
The National Air Deposition Network (NADP) maintains a large number of air monitoring sites throughout the United States and data collected can be accessed on the web (www.nadp.sws.uiuc.edu). There are four NADP collection sites within 25-40 miles of Calvert County but we are not aware of any air monitoring sites in the County. Until the development of the Dominion Cove Point project there has been only limited concern regarding air quality. The major issue was that polluted air coming from coal-fired power plants in the Ohio valley would move eastward on prevailing winds and stall over the Calvert County region because of on-shore Bay breezes during summer and thus create poor local air quality. A recent study from the Centers for Disease Control (CDC) reports that Calvert’s air pollutant level is 13.27 ug/m3. More information is available at: http://wonder.cdc.gov/wonder/help/PM.html#County.
Patuxent River Estuary:
The Patuxent River and estuary is the longest river/estuary ecosystem in the State of Maryland. The river originates in northern Maryland and flows 110 miles to the Chesapeake Bay. Seven
counties border the river or estuary, including Calvert County. The portion of the estuary in northern Calvert County is shallow and bordered by extensive tidal marshes. In fact, in terms of surface area, there is about 5 times more tidal marsh than estuarine open waters. South of the MD Route 231 Bridge at Hallowing Point the estuary broadens and deepens and is stratified from spring through early fall (more salty water towards the bottom and fresher water nearer the surface). Such stratification inhibits mixing of such important elements as oxygen from surface to deeper waters, especially during warm periods of the year, leading to oxygen stress and loss of habitat for many estuarine species.
Available data indicate the Patuxent estuary during the 1950s and early 1960s was characterized by reasonably clear water, adequate dissolved oxygen in deep waters and abundant and diverse sea grass communities along the shorelines and out to waters in excess of 10 feet deep and deeper in a few areas. However, this changed rapidly during the late 1960s and early 1970s. Sea grasses disappeared throughout the estuary by 1970 (earlier in the upper areas of the estuary), water clarity decreased and low dissolved oxygen areas (dead zones) developed. The deterioration of water and habitat quality in the estuary occurred during the same period when development in the upper basin was intense with a great deal of land conversion to urban and suburban uses and use of the river for disposal of water from waste water treatment plants (WWTP). Currently there are 9 major WWTPs (and many small WWTPs) discharging about 70 million gallons per day of nutrient rich wastewater to the river and estuary. There have been a series of up-grades to the WWTPs and additional up-grades are currently being constructed. However, water and habitat quality remains poor in the Patuxent River and estuary. The latest Report Card for the Patuxent had a grade of D, among the lowest in the entire Bay region (see www.ecoreportcard.org for more detailed information). Obviously, much yet needs to be done to restore this estuary. Additional and detailed information concerning the Patuxent River estuary can be found at www.Chesapeakebay.net .
The Chesapeake Bay constitutes the eastern boundary of Calvert County stretching for about 30 miles from north beach to Solomons Island. This stretch of shoreline also represents the largest exposure of Miocene deposits in the world. The Chesapeake Bay has often been characterized as a huge natural resource-based engine and Calvert County benefits from these activities. Specifically, recreational and commercial fishing, shoreline real estate, recreational boating, tourism and retirement communities are all directly or indirectly based on attributes of the Bay.
Much of this economic engine depends on good water and habitat quality of the Bay, as it does for the Patuxent River estuary. Currently, and for the past 4-5 decades, there have been serious water quality issues in the Bay and the most severe water and habitat problems occur in the mid-portion of the Bay, some of which is adjacent to Calvert County. Major impacts include algal blooms, persistent dead zones (lack of oxygen in the water) and the disappearance of sea grasses along the edges of the Bay shoreline and in tributary creeks as well as more complicated issues of estuarine chemistry. The region is currently dealing with a major program designed to reduce excessive nutrient and sediment inputs to the Bay and rivers (EPA and State Total Maximum Daily Load program; TMDL) and via these efforts to restore adequate water quality. In areas of the Bay and tributaries where nutrient reductions have been realized the ecological responses have been as expected and very favorable. A huge amount of information is available concerning past and current features of the Bay. A good entry to this information can be found at www.chesapeakebay.net .