Drought Watch Issued in Parts of the Lower Susquehanna River Watershed

The Pennsylvania Department of Environmental Protection has issued a “drought watch” for much of the state’s Susquehanna basin including Dauphin, Lebanon, and Perry Counties—plus those counties to their north.  Residents are asked to conserve water in the affected areas.

Irrigation of a manure-covered field.
Water conservation measures are voluntary during a drought watch, and most consumers try to cut back on nonessential use.  For many though, threats to water supply and water quality generate little concern.  This evening, on this farm along a Dauphin County waterway undergoing restoration, we shouldn’t be too surprised to see lots of water being pumped from the creek to soak down liquid manure that was spread on the fields earlier in the week.  This happens to be the only property along a five-mile segment of stream that still allows cattle and draft horses to wade, defecate, and urinate in the water.  It is the only parcel for nearly seven miles that has eroding banks of legacy sediments that are maintained denuded of nearly all vegetation.  Despite some beneficial practices like the use of cover crops, it’s a polluter.  And now its operator appears to be engaged in something new: “stream dewatering”.  With three irrigation guns in operation, this farmer was easily pumping and removing up to one half or more of the creek’s flow, which at the time, according to a United States Geological Survey gauge less than a mile upstream, was only about 3 cubic feet per second or 1,100 gallons per minute (G.P.M.).  That doesn’t let much for the municipalities downstream that rely upon this waterway as a supplemental source of drinking water, does it?  Such a large reduction in base flow can threaten the survival of fish and other aquatic inhabitants in the creek, particular during hot summer weather when dissolved oxygen levels can be at their lowest of the year.  Water is like a lot of other necessities, no one really gives it a second thought until they don’t have it; and as long as I have mine, that’s all that really matters.

Three Mile Island and Agnes: Fifty Years Later

Fifty years ago this week, the remnants of Hurricane Agnes drifted north through the Susquehanna River basin as a tropical storm and saturated the entire watershed with wave after wave of torrential rains.  The storm caused catastrophic flooding along the river’s main stem and along many major tributaries.  The nuclear power station at Three Mile Island, then under construction, received its first major flood.  Here are some photos taken during the climax of that flood on June 24, 1972.  The river stage as measured just upstream of Three Mile Island at the Harrisburg gauge crested at 33.27 feet, more than 10 feet above flood stage and almost 30 feet higher than the stage at present.  At Three Mile Island and Conewago Falls, the river was receiving additional flow from the raging Swatara Creek, which drains much of the anthracite coal region of eastern Schuylkill County—where rainfall from Agnes may have been the heaviest.

Three Mile Island flooding from Agnes 1972.
1972-  From the river’s east shore at the mouth of Conewago Creek, Three Mile Island’s “south bridge” crosses the Susquehanna along the upstream edge of Conewago Falls.  The flood crested just after covering the roadway on the span.  Floating debris including trees, sections of buildings, steel drums, and rubbish began accumulating against the railings on the bridge’s upstream side, leading observers to speculate that the span would fail.  When a very large fuel tank, thousands of gallons in capacity, was seen approaching, many thought it would be the straw that would break the camel’s back.  It wasn’t, but the crashing sounds it made as it struck the bridge then turned and began rolling against the rails was unforgettable.  (Larry L. Coble, Sr. image)
Three Mile Island flooding from Agnes 1972.
1972-  In this close-up of the preceding photo, the aforementioned piles of junk can be seen along the upstream side of the bridge (behind the sign on the right).  The fuel tank struck and was rolling on the far side of this pile.  (Larry L. Coble, Sr. image)
2022-  Three Mile Island’s “south bridge” as it appeared this morning, June 24,2022.
Three Mile Island flooding from Agnes 1972.
1972-  The railroad along the east shore at Three Mile Island’s “south bridge” was inundated by rising water.  This flooded automobile was one of many found in the vicinity.  Some of these vehicles were overtaken by rising water while parked, others were stranded while being driven, and still others floated in from points unknown.  (Larry L. Coble, Sr. image)
2022-  A modern view of the same location.
Three Mile Island flooding from Agnes 1972.
1972-  At the north end of Three Mile Island, construction on Unit 1 was halted.  The completed cooling towers can be seen to the right and the round reactor building can be seen behind the generator building to the left.  The railroad grade along the river’s eastern shore opposite the north end of the island was elevated enough for this train to stop and shelter there for the duration of the flood.  (Larry L. Coble, Sr. image)
2022-  Three Mile Island Unit 1 as it appears today: shut down, defueled, and in the process of deconstruction.
Three Mile Island flooding from Agnes 1972.
1972-  In March of 1979, the world would come to know of Three Mile Island Unit 2.  During Agnes in June of 1972, flood waters surrounding the plant resulted in a delay of its construction.  In the foreground, note the boxcar from the now defunct Penn Central Railroad.  (Larry L. Coble, Sr. image)
2022-  A current look at T.M.I. Unit 2, shut down since the accident and partial meltdown in 1979.

Pictures capture just a portion of the experience of witnessing a massive flood.  Sometimes the sounds and smells of the muddy torrents tell us more than photographs can show.

Aside from the booming noise of the fuel tank banging along the rails of the south bridge, there was the persistent roar of floodwaters, at the rate of hundreds of thousands of cubic feet per second, tumbling through Conewago Falls on the downstream side of the island.   The sound of the rapids during a flood can at times carry for more than two miles.  It’s a sound that has accompanied the thousands of floods that have shaped the falls and its unique diabase “pothole rocks” using abrasives that are suspended in silty waters after being eroded from rock formations in the hundreds of square miles of drainage basin upstream.  This natural process, the weathering of rock and the deposition of the material closer to the coast, has been the prevailing geologic cycle in what we now call the Lower Susquehanna River Watershed since the end of the Triassic Period, more than two hundred million years ago.

More than the sights and sounds, it was the smell of the Agnes flood that warned witnesses of the dangers of the non-natural, man-made contamination—the pollution—in the waters then flowing down the Susquehanna.

Because they float, gasoline and other fuels leaked from flooded vehicles, storage tanks, and containers were most apparent.  The odor of their vapors was widespread along not only along the main stem of the river, but along most of the tributaries that at any point along their course passed through human habitations.

Blended with the strong smell of petroleum was the stink of untreated excrement.  Flooded treatment plants, collection systems overwhelmed by stormwater, and inundated septic systems all discharged raw sewage into the river and many of its tributaries.  This untreated wastewater, combined with ammoniated manure and other farm runoff, gave a damaging nutrient shock to the river and Chesapeake Bay.

Adding to the repugnant aroma of the flood was a mix of chemicals, some percolated from storage sites along watercourses, and yet others leaking from steel drums seen floating in the river.  During the decades following World War II, stacks and stacks of drums, some empty, some containing material that is very dangerous, were routinely stored in floodplains at businesses and industrial sites throughout the Susquehanna basin.  Many were lifted up and washed away during the record-breaking Agnes flood.  Still others were “allowed” to be carried away by the malicious pigs who see a flooding stream as an opportunity to “get rid of stuff”.  Few of these drums were ever recovered, and hundreds were stranded along the shoreline and in the woods and wetlands of the floodplain below Conewago Falls.  There, they rusted away during the next three decades, some leaking their contents into the surrounding soils and waters.  Today, there is little visible trace of any.

During the summer of ’72, the waters surrounding Three Mile Island were probably viler and more polluted than at any other time during the existence of the nuclear generating station there.  And little, if any of that pollution originated at the facility itself.

The Susquehanna’s floodplain and water quality issues that had been stashed in the corner, hidden out back, and swept under the rug for years were flushed out by Agnes, and she left them stuck in the stinking mud.

No Need to Hurry

It’s that time of year when one may expect to find migratory Neotropical songbirds feeding among the foliage of trees and shrubs in the forests, woodlots, and thickets of the lower Susquehanna valley.

During a late afternoon stroll through a headwaters forest east of Conewago Falls outside Mount Gretna, I was pleased to finally come upon a noisy gathering of about two dozen birds.  It had, previous to that, been a quiet two hours of walking, only the rumble of an approaching thunderstorm punctuated the silence.  Among this little flock were some chickadees, robins, Gray Catbirds, an Eastern Towhee (Pipilo erythrophthalmus), and a Hairy Woodpecker (Dryobates villosus).  Besides the catbirds, there were two other species of Neotropical migrants; both were warblers.  No less than six Black-throated Blue Warblers (Setophaga caerulescens) were  vying for positions in the trees from which they could investigate the stranger on the footpath below.  And among the understory shrubs there were at least as many Ovenbirds (Seiurus aurocapilla) satisfying a similar curiosity.

The Black-throated Blue Warbler nests to the north of the lower Susquehanna valley, which it transits as a common spring and fall migrant.  On their wintering grounds, they have a thing for warm weather and the better part of a P.B. & J. sandwich.
Throughout the Susquehanna watershed, the Ovenbird is a common ground-nesting species in deciduous forests with moderately vegetated understories.  The birds seen today may have been a family group that has not yet begun the journey south.

When they depart the Susquehanna valley, these two warbler species will be southbound for wintering ranges that include Florida, many of the Caribbean Islands, Central America, and, for the Ovenbirds, northern South America.  Their flights occur at night.  During the breeding season and while migrating, both feed primarily on insects and other arthropods .  On the wintering grounds, they will consume some fruit.  It is during their time in the tropics that the Black-throated Blue Warbler sometimes visits feeding stations that offer grape jelly, much to the delight of bird enthusiasts.

Black-throated Blue Warblers and Ovenbirds commonly winter on the Florida peninsula and in the Bahamas.  With the major tropical cyclone Hurricane Dorian presently ripping through the region, these birds are better off taking their time getting there.  There’s no need to hurry.  The longer they and the other Neotropical migrants hang around, the more we get to enjoy them anyway.  So get out there to see them before they go—and remember to look up.

Category 4 Hurricane Dorian at 9:06 EDT on September 2, 2019.  If you’re headed that direction, there’s no need to hurry.  Note the cloud-free skies over much of the mainland.  (NOAA National Environmental Satellite, Data, and Information Service image)
A massive bird migration is indicated on Doppler radar in the clear skies over the eastern United States tonight (blue and green over most of the mainland).  In this loop of composite radar images from the southeastern states, note the relative absence of a flight over the Florida peninsula where the outer precipitation bands of Hurricane Dorian can be seen.  Note too that there appears to be a heavy concentration of birds flying in a southwest direction to cross the Gulf of Mexico, thus continuing their journey to Central or South America while avoiding the deadly hurricane and a much smaller tropical disturbance off the shores of Texas and Tamaulipas, Mexico.  (NOAA/National Weather Service image)

Shocking Fish Photos!

There are two Conewago Creek systems in the Lower Susquehanna River Watershed.  One drains the Gettysburg Basin west of the river, mostly in Adams and York Counties, then flows into the Susquehanna at the base of Conewago Falls.  The other drains the Gettysburg Basin east of the river, flowing through Triassic redbeds of the Gettysburg Formation and York Haven Diabase before entering Conewago Falls near the south tip of Three Mile Island.  Both Conewago Creeks flow through suburbia, farm, and forest.  Both have their capacity to support aquatic life impaired and diminished by nutrient and sediment pollution.

This week, some of the many partners engaged in a long-term collaboration to restore the east shore’s Conewago Creek met to have a look at one of the prime indicators of overall stream habitat health—the fishes.  Kristen Kyler of the Lower Susquehanna Initiative organized the effort.  Portable backpack-mounted electrofishing units and nets were used by crews to capture, identify, and count the native and non-native fishes at sampling locations which have remained constant since prior to the numerous stream improvement projects which began more than ten years ago.  Some of the present-day sample sites were first used following Hurricane Agnes in 1972 by Stambaugh and Denoncourt and pre-date any implementation of sediment and nutrient mitigation practices like cover crops, no-till farming, field terracing, stormwater control, nutrient management, wetland restoration, streambank fencing, renewed forested stream buffers, or modernized wastewater treatment plants.  By comparing more recent surveys with this baseline data, it may be possible to discern trends in fish populations resulting not only from conservation practices, but from many other variables which may impact the Conewago Creek Warmwater Stream ecosystem in Dauphin, Lancaster, and Lebanon Counties.

So here they are.  Enjoy these shocking fish photos.

Matt Kofroth, Watershed Specialist with the Lancaster County Conservation District, operates the electrofishing wand in Conewago Creek while his team members prepare to net and collect momentarily-stunned fish.  Three other electrofishing units operated by staff from the Susquehanna River Basin Commission and aided by teams of netters were in action at other sample locations along the Conewago on this day.
Really big fish, such as this Common Carp (Cyprinus carpio), were identified, counted, and immediately returned to the water downstream of the advancing electrofishing team.  Koi of the garden pond are a familiar variety of Common Carp, a native of Asia.
Other fish, such as the Swallowtail Shiner, Redbreast Sunfish (Lepomis auritus), Fallfish, and suckers seen here,  were placed in a sorting tank.
Fallfish (Semotilus corporalis) are very active and require plenty of dissolved oxygen in the water to survive.  Fallfish, Rainbow Trout (Oncorhynchus mykiss), and Smallmouth Bass (Micropterus dolomieu) were quickly identified and removed from the sorting tank for release back into the stream.  Other larger, but less active fish, including suckers, quickly followed.
Small fish like minnows were removed from the sorting tank for a closer look in a hand-held viewing tank.  This Fathead Minnow (Pimephales promelas) was identified, added to the tally sheet, and released back into the Conewago.  The Fathead Minnow is not native to the Susquehanna drainage.  It is the minnow most frequently sold as bait by vendors.
A breeding condition male Bluntnose Minnow (Pimephales notatus).
The Cutlips Minnow (Exoglossum maxillingua) is a resident of clear rocky streams.  Of the more than 30 species collected during the day, two native species which are classified as intolerant of persisting stream impairment were found: Cutlips Minnow and Swallowtail Shiner.
This young River Chub (Nocomis micropogon) is losing its side stripe.  It will be at least twice as large at adulthood.
The Eastern Blacknose Dace (Rhinichthys atratulus) is found in clear water over pebble and stone substrate..
The Longnose Dace (Rhinichthys cataractae) is another species of pebbly rocky streams.
A juvenile Golden Shiner (Notemigonus crysoleucas).  Adults lack the side stripe and grow to the size of a sunfish.
A Swallowtail Shiner (Notropis procne) and a very young White Sucker (Catostomus commersonii) in the upper left of the tank.
A Spotfin Shiner (Cyprinella spiloptera).
A breeding male Spotfin Shiner.  Show-off!
The Margined Madtom (Noturus insignis) is a small native catfish of pebbly streams.
The Banded Killifish (Fundulus diaphanus) is adept at feeding upon insects, including mosquitos.
A young Rock Bass (Ambloplites rupestris).  This species was introduced to the Susquehanna and its tributaries.
The Greenside Darter (Etheostoma blennioides) is not native to the Susquehanna basin.  The species colonized the Conewago Creek (east) from introduced local populations within the last five years.
The Tessellated Darter (Etheostoma olmstedi) is a native inhabitant of the Susquehanna and its tributaries.
The stars of the day were the American Eels (Anguilla rostrata).
After collection, each eel was measured and weighed using a scale and dry bucket.  This specimen checked in at 20 inches and one pound before being released.
Prior to the construction of large dams, American Eels were plentiful in the Susquehanna and its tributaries, including the Conewago.  They’ve since been rarities for more than half a century.  Now they’re getting a lift.
American Eels serve as an intermediate host for the microscopic parasitic glochidia (larvae) of the Eastern Elliptio (Elliptio complanata), a declining native freshwater mussel of the Lower Susquehanna River Watershed.  While feeding on their host (usually in its gills), the glochidia cause little injury and soon drop off to continue growth, often having assured distribution of their species by accepting the free ride.  Freshwater mussels are filter feeders and improve water quality.  They grow slowly and can live for decades.
American Eels are a catadromous species, starting life as tiny glass eels in the saltwater of the Atlantic Ocean, then migrating to tidal brackish marshes and streams (males) or freshwater streams (females) to mature.  This 20-incher probably attempted to ascend the Susquehanna as an elver in 2016 or 2017.  After hitching a ride with some friendly folks, she bypassed the three largest dams on the lower Susquehanna (Conowingo, Holtwood, and Safe Harbor) and arrived in the Conewago where she may remain and grow for ten years or more.  To spawn, a perilous and terminally fatal journey to the Sargasso Sea awaits her.  (You may better know the area of the Sargasso Sea as The Bermuda Triangle…a perilous place to travel indeed!)

SOURCES

Normandeau Associates,  Inc. and Gomez and Sullivan.  2018.  Muddy Run Pumped Storage Project Conowingo Eel Collection Facility FERC Project 2355.  Prepared for Exelon.

Stambaugh, Jr., John W., and Robert P. Denoncourt.  1974.  A Preliminary Report on the Conewago Creek Faunal Survey, Lancaster County, Pennsylvania.  Proceedings of the Pennsylvania Academy of Sciences.  48: 55-60.