Testimony by Glenn A. Carowan, Jr., Manager Blackwater NWR
Chesapeake Marshlands National Wildlife Refuge Complex
2145 Key Wallace Drive
Cambridge, MD 21613
Madam Chairman, members of the Committee, my name is Glenn Carowan. I am the manager of Blackwater National Wildlife Refuge and Project Leader of the Chesapeake Marshlands National Wildlife Refuge Complex, a group of refuges in the Chesapeake Bay that include Susquehanna, Eastern Neck, Blackwater, and Martin Refuges and a number of different island divisions extending into Tangier Sound. Thank you for the opportunity to testify today on the potential issues resulting from proposed developments within the Little Blackwater River Watershed, and the impacts that we perceive may affect Blackwater Refuge's future management and mission as well as the Fish and Wildlife Service's responsibilities for managing our nation's trust wildlife resources. My presentation today will focus on Why We Care about the potential planned developments and what happens in the Little Blackwater River watershed; what we believe are some of the more pertinent impacts to the refuge's wildlife, its mission, and future management that will affect all of Maryland and overall health of the Chesapeake Bay; and several recommendations that we have made to address the concerns we have raised.
We care about what happens in the Little Blackwater Watershed because Blackwater Refuge is located within the watershed and is a very special place that conserves and manages a significant number of trust resources for the U.S. Fish and Wildlife Service; migratory birds, anadromous and interjurisdictional fish, and threatened and endangered species. Blackwater is one of over 545 National Wildlife Refuges within the National Wildlife Refuge System managed by the U.S. Fish and Wildlife Service. Established in 1933, the current refuge encompasses approximately 28,000 acres in Dorchester County, and is located approximately 10 miles south of Cambridge. Blackwater Refuge, shown in dark green, is immediately downstream of all the proposed developments within the newly expanded city limits of Cambridge. All the runoff within the Little Blackwater River watershed eventually ends up in the heart of Blackwater Refuge before joining with the Blackwater River and finding its way into Fishing Bay and eventually the Chesapeake.
Blackwater Refuge is truly a remarkable place in terms of its abundance and diversity of wildlife. Over 300 species of migratory birds depend on this very special refuge in our nation's largest estuary. Eight Anadromous fish species, and nine interjurisdictional fish species have historically depended on refuge waters to live and reproduce. The detritus filled waters that find their way from the refuge's marshes into the adjoining Fishing Bay support the second most significant nursery for blue crab larva in the Chesapeake Bay.
Over 270 state and federally threatened and endangered species call the refuge home, including the largest nesting population of bald eagles north of Florida on the Atlantic Coast, the largest extant population of Delmarva fox squirrels in the world, and some extremely rare aquatic plants like the frog bit. A significant number of these species depend on healthy aquatic environments to survive and successfully reproduce. Blackwater Refuge is an Ramsar site or a wetland of international importance, and because of the diversity and abundance of bird life, particularly waterfowl and secretive marsh birds, has been designated as an International Important Bird Area. Some of the Nation's and Chesapeake Bay region's most imperiled wetland habitat types are conserved because of the refuge, which, along with the other refuges in the Complex, help to conserve over 1/3 of all the tidal wetlands in Maryland, and 16% of the remaining submerged aquatic vegetation in the Bay. The northernmost expanses of three-square bulrush marsh that provide habitat for thousands of waterfowl and rare marsh birds like the black rail abound on the refuge. But these unique habitats are increasingly threatened by rising water levels. And finally we care because Blackwater Refuge conserves these trust resources for the benefit of the American people; all people, not just the 250,000 annual visitors who support the local economy to the tune of about $4 million annually. The refuge is a significant contributor to the tax base producing approximately $500,000 annually in local, state, and federal tax revenue, requiring almost no services from the local governments.
In the first segment, I've tried to explain what makes Blackwater Refuge a very special place regionally, nationally, and internationally. Now I'd like to focus on two major issues affecting the refuge and the potential impacts to the refuge from the proposed developments on the Little Blackwater River. Blackwater National Wildlife Refuge has lost approximately 8000 acres of emergent marsh since 1938. The confluence of the Little Blackwater and Blackwater Rivers shows clearly how dramatically our three-square bulrush marshes converted to open water in the 50 years between 1938 and 1989. The five principal causes of marsh loss have been identified as rising water levels associated with sea level rise and the impounding of waters upstream of Shorters Wharf Road which acts as a dam across the marsh; subsidence of the ground attributed to water removal from the aquifer and/or a re-flattening of the earth's mantle; erosion of shorelines due to increased wave action; salt water intrusion from sea level rise and subsidence; and finally, excessive herbivory by both native and exotic wildlife such as historical overpopulations of native muskrats and the nutria that was introduced into these marshes in the early 1940's.
Curt Larson, with the U.S. Geological Survey, completed a model of marsh loss that shows what the healthy marsh looked like in 1900 (the area shown in red is healthy bulrush marsh and the blue is open water), …how the healthy marsh had decreased by 1980, and …what the marsh would look like in 2050 given the amounts of water entering the refuge in Year 2000. From experience, we know that marsh accretion cannot currently keep pace with rising water levels under existing conditions, so a major issue for the proposed developments and the regulating entities has to be how to address potential added contributions in water quantity. Creating impervious water surfaces where once agricultural lands and pervious surfaces existed is a major issue that can significantly potentially increase the quantity of water entering the Blackwater River basin. The Little Blackwater River watershed currently drains almost 23,000 acres directly into the refuge. Potential declines in water quality may adversely affect all Service trust resources including critical fish and wildlife habitats. Blackwater Refuge in the past 10 years has increased its management efforts to restore the thousands of acres of wetlands that have converted to open water. Recently a weir has been approved for construction in the upper Blackwater River to eliminate salt water intrusion from Stewarts Canal. The refuge has spent millions of dollars to extirpate nutria, and is currently working with the State to eradicate nutria on the adjoining Fishing Bay WMA and private lands. We have also reduced the resident Canada goose population from almost 5,000 to about 400, and in doing so have significantly reduced the excessive herbivory that these injurious species cause.
But the most exciting endeavor recently has been the beneficial use of dredge material to restore our internationally significant wetlands. Our most significant action taken to effectively combat marsh loss and restore the 8,000 acres of emergent marshlands that have converted to open water within the past 60 years, has been a developing partnership with the Maryland Port Administration and Corps to utilize dredge materials to either "grout" in shallow areas as shown here, or……to actually fill deeper water areas and subsequent plant the new marsh with a variety of marsh plants. The 15 acre demonstration in 2003 was successful beyond our even our wildest expectations… In just four short months, the restored areas produced a vigorous and extremely healthy marsh ecosystem. The results were outstanding. After two years of monitoring these sites, we are even more convinced that these techniques can be applied on a much larger scale. The Maryland portion of the approach channel to the Port of Baltimore requires the removal of 3 to 4 million cubic yards of dredge material annually. Dorchester Restoration provides placement opportunities for dredged material for 12 to 50 years and would restore the watershed. Our restoration goal is to recreate the lost marshlands by 2020 with beneficial use of dredge materials. This extremely important effort may be jeopardized by the changes in water quantity and quality associated with the proposed developments.
We are asking for assurances that these types of management programs are not adversely impacted. In our October 27, 2005 letter to the Director of Dorchester Planning and Zoning, the first recommendation the Fish and Wildlife Service asked be completed before developments are allowed was to accomplish a baseline inventory of the natural resources in the Little Blackwater River, including water quality and quantity, storm water management, and fishery resources. We have recommended that the baseline inventory and Index of Biotic Integrity be completed by June 2006. If there exists any doubt that there will be an increase in the quantity of stormwater runoff resulting from these developments that may potentially impact wildlife and economic resources as important as those at Blackwater Refuge, and where the resulting increase in runoff could adversely impact the ability of the Port of Baltimore and the Army Corps to beneficially utilize millions of cubic yards of dredge material for the maintenance of the shipping channels that contribute substantially to the overall economy of Maryland and the ultimate restoration of thousands of acres of marshlands, that it must be of the highest priority to the developer and local government officials to conduct a study to determine a baseline of existing water quality and quantity information, and to subsequently model the flow in the Blackwater River before these developments are allowed to proceed. A monitoring program should be maintained annually to determine if changes are occurring. The development communities and their Civic Associations must be held accountable for conducting the annual monitoring program. If results of the monitoring program demonstrate that the natural resources of the Little Blackwater River are adversely affected by water quality and quantity problems, then we recommend the Association be held responsible for mitigation of the natural resource.
In closing, I'd like to once again thank the committee for inviting me to testify about our concerns and issues regarding proposed developments in the Little Blackwater River watershed and the potential impacts to the Refuge's mission and future management plans. We are hopeful that the responsible officials will implement our recommendations to ensure that the natural resources and wild places that are drawing new residents to our area will not be adversely impacted by potential changes in water quality, quantity, stormwater management, and increased sedimentation that these new developments may cause.