Are you worried about your well running dry this summer? Are you wondering if your public water supply is going to implement use restrictions in coming months? If we do suddenly enter a wet spell again, are you concerned about losing valuable rainfall to flooding? A sensible person should be curious about these issues, but here in the Lower Susquehanna River Watershed, we tend to take for granted the water we use on a daily basis.
This Wednesday, June 7, you can learn more about the numerous measures we can take, both individually and as a community, to recharge our aquifers while at the same time improving water quality and wildlife habitat in and around our streams and rivers. From 5:30 to 8:00 P.M., the Chiques Creek Watershed Alliance will be hosting its annual Watershed Expo at the Manheim Farm Show grounds adjacent to the Manheim Central High School in Lancaster County. According to the organization’s web page, more than twenty organizations will be there with displays featuring conservation, aquatic wildlife, stream restoration, Honey Bees, and much more. There will be games and custom-made fish-print t-shirts for the youngsters, plus music to relax by for those a little older. Look for rain barrel painting and a rain barrel giveaway. And you’ll like this—admission and ice cream are free. Vendors including food trucks will be onsite preparing fare for sale.
And there’s much more.
To help recharge groundwater supplies, you can learn how to infiltrate stormwater from your downspouts, parking area, or driveway…
…there will be a tour of a comprehensive stream and floodplain rehabilitation project in Manheim Memorial Park adjacent to the fair grounds…
…and a highlight of the evening will be using an electrofishing apparatus to collect a sample of the fish now populating the rehabilitated segment of stream…
…so don’t miss it. We can hardly wait to see you there!
This month, the International Union for Conservation of Nature (I.U.C.N.) added the Migratory Monarch Butterfly (Danaus plexippus plexippus) to its “Red List of Threatened Species”, classifying it as endangered. Perhaps there is no better time than the present to have a look at the virtues of replacing areas of mowed and manicured grass with a wildflower garden or meadow that provides essential breeding and feeding habitat for Monarchs and hundreds of other species of animals.
If you’re not quite sure about finally breaking the ties that bind you to the cult of lawn manicuring, then compare the attributes of a parcel maintained as mowed grass with those of a space planted as a wildflower garden or meadow. In our example we’ve mixed native warm season grasses with the wildflowers and thrown in a couple of Eastern Red Cedars to create a more authentic early successional habitat.
Still not ready to take the leap. Think about this: once established, the wildflower planting can be maintained without the use of herbicides or insecticides. There’ll be no pesticide residues leaching into the soil or running off during downpours. Yes friends, it doesn’t matter whether you’re using a private well or a community system, a wildflower meadow is an asset to your water supply. Not only is it free of man-made chemicals, but it also provides stormwater retention to recharge the aquifer by holding precipitation on site and guiding it into the ground. Mowed grass on the other hand, particularly when situated on steep slopes or when the ground is frozen or dry, does little to stop or slow the sheet runoff that floods and pollutes streams during heavy rains.
What if I told you that for less than fifty bucks, you could start a wildflower garden covering 1,000 square feet of space? That’s a nice plot 25′ x 40′ or a strip 10′ wide and 100′ long along a driveway, field margin, roadside, property line, swale, or stream. All you need to do is cast seed evenly across bare soil in a sunny location and you’ll soon have a spectacular wildflower garden. Here at the susquehannawildllife.net headquarters we don’t have that much space, so we just cast the seed along the margins of the driveway and around established trees and shrubs. Look what we get for pennies a plant…
Here’s a closer look…
All this and best of all, we never need to mow.
Around the garden, we’ve used a northeast wildflower mix from American Meadows. It’s a blend of annuals and perennials that’s easy to grow. On their website, you’ll find seeds for individual species as well as mixes and instructions for planting and maintaining your wildflower garden. They even have a mix specifically formulated for hummingbirds and butterflies.
Nothing does more to promote the spread and abundance of non-native plants, including invasive species, than repetitive mowing. One of the big advantages of planting a wildflower garden or meadow is the opportunity to promote the growth of a community of diverse native plants on your property. A single mowing is done only during the dormant season to reseed annuals and to maintain the meadow in an early successional stage—preventing reversion to forest.
For wildflower mixes containing native species, including ecotypes from locations in and near the Lower Susquehanna River Watershed, nobody beats Ernst Conservation Seeds of Meadville, Pennsylvania. Their selection of grass and wildflower seed mixes could keep you planting new projects for a lifetime. They craft blends for specific regions, states, physiographic provinces, habitats, soils, and uses. Check out these examples of some of the scores of mixes offered at Ernst Conservation Seeds…
Pasture, Grazing, and Hay Mixes
Warm-season Grass Mixes
Retention Basin Mixes
Floodplain and Riparian Buffer Mixes
Rain Garden Mixes
Steep Slope Mixes
Solar Farm Mixes
Strip Mine Reclamation Mixes
We’ve used their “Showy Northeast Native Wildflower and Grass Mix” on streambank renewal projects with great success. For Monarchs, we really recommend the “Butterfly and Hummingbird Garden Mix”. It includes many of the species pictured above plus “Fort Indiantown Gap” Little Bluestem, a warm-season grass native to Lebanon County, Pennsylvania, and milkweeds (Asclepias), which are not included in their northeast native wildflower blends. More than a dozen of the flowers and grasses currently included in this mix are derived from Pennsylvania ecotypes, so you can expect them to thrive in the Lower Susquehanna River Watershed.
In addition to the milkweeds, you’ll find these attractive plants included in Ernst Conservation Seed’s “Butterfly and Hummingbird Garden Mix”, as well as in some of their other blends.
Why not give the Monarchs and other wildlife living around you a little help? Plant a wildflower garden or meadow. It’s so easy, a child can do it.
It was a routine occurrence in many communities along tributaries of the lower Susquehanna River during the most recent two months. The rain falls like it’s never going to stop—inches an hour. Soon there is flash flooding along creeks and streams. Roads are quickly inundated. Inevitably, there are motorists caught in the rising waters and emergency crews are summoned to retrieve the victims. When the action settles, sets of saw horses are brought to the scene to barricade the road until waters recede. At certain flood-prone locations, these events are repeated time and again. The police, fire, and Emergency Medical Services crews seem to visit them during every torrential storm—rain, rescue, rinse, and repeat.
We treat our local streams and creeks like open sewers. Think about it. We don’t want rainwater accumulating on our properties. We pipe it away and grade the field, lawn, and pavement to roll it into the neighbor’s lot or into the street—or directly into the waterway. It drops upon us as pure water and we instantly pollute it. It’s a method of diluting all the junk we’ve spread out in its path since the last time it rained. A thunderstorm is the big flush. We don’t seem too concerned about the litter, fertilizer, pesticides, motor fluids, and other consumer waste it takes along with it. Out of sight, out of mind.
Perhaps our lack of respect for streams and creeks is the source of our complete ignorance of the function of floodplains.
Floodplains are formed over time as hydraulic forces erode bedrock and soils surrounding a stream to create adequate space to pass flood waters. As floodplains mature they become large enough to reduce flood water velocity and erosion energy. They then function to retain, infiltrate, and evaporate the surplus water from flood events. Microorganisms, plants, and other life forms found in floodplain wetlands, forests, and grasslands purify the water and break down naturally-occurring organic matter. Floodplains are the shock-absorber between us and our waterways. And they’re our largest water treatment facilities.
Why is it then, that whenever a floodplain floods, we seem motivated to do something to fix this error of nature? Man can’t help himself. He has a compulsion to fill the floodplain with any contrivance he can come up with. We dump, pile, fill, pave, pour, form, and build, then build some more. At some point, someone notices a stream in the midst of our new creation. Now it’s polluted and whenever it storms, the darn thing floods into our stuff—worse than ever before. So the project is crowned by another round of dumping, forming, pouring, and building to channelize the stream. Done! Now let’s move all our stuff into our new habitable space.
The majority of the towns in the lower Susquehanna valley with streams passing through them have impaired floodplains. In many, the older sections of the town are built on filled floodplain. Some new subdivisions highlight streamside lawns as a sales feature—plenty of room for stockpiling your accoutrements of suburban life. And yes, some new homes are still being built in floodplains.
When high water comes, it drags tons of debris with it. The limbs, leaves, twigs, and trees are broken down by natural processes over time. Nature has mechanisms to quickly cope with these organics. Man’s consumer rubbish is another matter. As the plant material decays, the embedded man-made items, particularly metals, treated lumber, plastics, Styrofoam, and glass, become more evident as an ever-accumulating “garbage soil” in the natural floodplains downstream of these impaired areas. With each storm, some of this mess floats away again to move ever closer to Chesapeake Bay and the Atlantic. Are you following me? That’s our junk from the curb, lawn, highway, or parking lot bobbing around in the world’s oceans.
Beginning in 1968, participating municipalities, in exchange for having coverage provided to their qualified residents under the National Flood Insurance Program, were required to adopt and enforce a floodplain management ordinance. The program was intended to reduce flood damage and provide flood assistance funded with premiums paid by potential victims. The program now operates with a debt incurred during severe hurricanes. Occurrences of repetitive damage claims and accusations that the program provides an incentive for rebuilding in floodplains have made the National Flood Insurance Program controversial.
In the Lower Susquehanna River Watershed there are municipalities that still permit new construction in floodplains. Others are quite proactive at eliminating new construction in flood-prone zones, and some are working to have buildings removed that are subjected to repeated flooding.
The tall seed-topped stems swaying in a summer breeze are a pleasant scene. And the colorful autumn shades of blue, orange, purple, red, and, of course, green leaves on these clumping plants are nice. But of the multitude of flowering plants, Big Bluestem, Freshwater Cordgrass, and Switchgrass aren’t much of a draw. No self-respecting bloom addict is going out of their way to have a gander at any grass that hasn’t been subjugated and tamed by a hideous set of spinning steel blades. Grass flowers…are you kidding?
O.K., so you need something more. Here’s more.
Meet the Partridge Pea (Chamaecrista fasciculata). It’s an annual plant growing in the Riverine Grasslands at Conewago Falls as a companion to Big Bluestem. It has a special niche growing in the sandy and, in summertime, dry soils left behind by earlier flooding and ice scour. The divided leaves close upon contact and also at nightfall. Bees and other pollinators are drawn to the abundance of butter-yellow blossoms. Like the familiar pea of the vegetable garden, the flowers are followed by flat seed pods.
But wait, here’s more.
In addition to its abundance in Conewago Falls, the Halberd-leaved Rose Mallow (Hibiscus laevis) is the ubiquitous water’s edge plant along the free-flowing Susquehanna River for miles downstream. It grows in large clumps, often defining the border between the emergent zone and shore-rooted plants. It is particularly successful in accumulations of alluvium interspersed with heavier pebbles and stone into which the roots will anchor to endure flooding and scour. Such substrate buildup around the falls, along mid-river islands, and along the shores of the low-lying Riparian Woodlands immediately below the falls are often quite hospitable to the species.
A second native wildflower species in the genus Hibiscus is found in the Conewago Falls floodplain, this one in wetlands. The Swamp Rose Mallow (H. moscheutos) is similar to Halberd-leaved Rose Mallow, but sports more variable and colorful blooms. The leaves are toothed without the deep halberd-style lobes and, like the stems, are downy. As the common name implies, it requires swampy habitat with ample water and sunlight.
In summary, we find Partridge Pea in the Riverine Grasslands growing in sandy deposits left by flood and ice scour. We find Halberd-leaved Rose Mallow rooted at the border between shore and the emergent zone. We find Swamp Rose Mallow as an emergent in the wetlands of the floodplain. And finally, we find marshmallows in only one location in the area of Conewago Falls. Bon ap’.
Newcomb, Lawrence. 1977. Newcomb’s Wildflower Guide. Little, Brown and Company. Boston, Massachusetts.
It was one of the very first of my memories. From the lawn of our home I could look across the road and down the hill through a gap in the woodlands. There I could see water, sometimes still with numerous boulders exposed, other times rushing, muddy, and roaring. Behind these waters was a great stone wall and beyond that a wooded hillside. I recall my dad asking me if I could see the dam down there. I couldn’t see a dam, just fascinating water and the gray wall behind it. I looked and searched but not a trace of a structure spanning the near to far shore was to be seen. Finally, at some point, I answered in the affirmative to his query; I could see the dam…but I couldn’t.
We lived in a small house in the village of Falmouth along the Susquehanna River in the northwest corner of Lancaster County over fifty years ago. A few years after we had left our riverside domicile and moved to a larger town, the little house was relocated to make way for an electric distribution sub-station and a second set of electric transmission wires in the gap in the woodlands. The Brunner Island coal-fired electric generating station was being upgraded downstream and, just upstream, a new nuclear-powered generating station was being constructed on Three Mile Island. To make way for the expanding energy grid, our former residence was trucked to a nearby boat landing where there were numerous other river shacks and cabins. Because it was placed in the floodplain, the building was raised onto a set of wooden stilts to escape high water. It didn’t help. The recording-breaking floods of Hurricane Agnes in June of 1972 swept the house away.
During the time we lived along the Susquehanna, the river experienced record-low flow rates, particularly in the autumn of 1963 and again in 1964. My dad was a dedicated 8mm home-movie photographer. Among his reels was film of buses parked haphazardly along the road (PA Route 441 today) near our home. Sightseers were coming to explore the widely publicized dry riverbed and a curious moon-like landscape of cratered rocks and boulders. It’s hard to fathom, but people did things like that during their weekends before football was invented. Scores of visitors climbed through the rocks and truck-size boulders inspecting this peculiar scene. My dad, his friends, and so many others with camera in hand were experiencing the amazing geological feature known as the Pothole Rocks of Conewago Falls.
The river here meets serious resistance as it pushes its way through the complex geology of south-central Pennsylvania. These hard dark-gray rocks, York Haven Diabase, are igneous in origin. Diabase sheets and sills intruded the Triassic sediments of the Gettysburg Formation here over 190 million years ago. It may be difficult to visualize, but these sediments were eroded from surrounding mountains into the opening rift valley we call the Gettysburg Basin. This rift and others in a line from Nova Scotia to Georgia formed as the supercontinent Pangaea began dividing into the continents we know today. Eventually the Atlantic Ocean rift would dominate as the active dynamic force and open to separate Africa from North America. The inactive Gettysburg Basin, filled with sediments and intruded by igneous diabase, would henceforth, like the mountainous highlands surrounding it, be subjected to millions of years of erosion. Of the regional rocks, the formations of Triassic redbeds, sandstones, and particularly diabase in the Gettysburg Basin are among the more resistant to the forces of erosion. Many less resistant older rocks, particularly those of surrounding mountains, are gone. Today, the remains of the Gettysburg Basin’s rock formations stand as rolling highlands in the Piedmont Province.
The weekend visitors in 1963 and 1964 marveled at evidence of the river’s fight to break down the hard York Haven Diabase. Scoured bedrock traced the water’s turbulent flow patterns through the topography of the falls. Meltwater from the receding glaciers of the Pleistocene Ice Ages thousands to tens of thousands of years ago raged in high volume abrasive-loaded torrents to sculpt the Pothole Rocks into the forms we see today. Our modern floodwaters with ice and fine suspended sediments continue to wear at the smooth rocks and boulders, yet few are broken or crumbled to be swept away. It’s a very slow process. The river elevation here drops approximately 19 feet in a quarter of a mile, a testament to the bedrock’s persisting resistance to erosion. Conewago Falls stands as a natural anomaly on a predominantly uniform gradient along the lower Susquehanna’s downhill path from the Appalachian Mountains to the Chesapeake Bay.
The scene of dangerous tumbling rapids during high flows, the drought and low water of 1963 and 1964 had left the falls to resemble a placid scene; a moonscape during a time when people were obsessed with mankind’s effort to visit earth’s satellite. Visitors saw the falls as few others had during the twentieth century. Much of it was due to the presence of the wall. I had to be a bit older than four years old to grasp it. You see the wall and the dam are one and the same. The wall is the York Haven Dam.
The initial segment, a crib dam constructed in 1885 by the York Haven Paper Company to supply water power to their mill, took advantage of the geomorphic features of the diabase bedrock of Conewago Falls to divert additional river flow into the abandoned Conewago Canal. The former canal, opened in 1797 to allow passage around the rapids along the west shore, was being used as a headrace to channel water into the grinding mill’s turbines. Strategic placement of this first wall directed as much water as possible toward the mill with the smallest dam practicable. The York Haven Power Company incorporated the paper mill’s crib dam into the “run-of-the-river” dam built through the falls from the electric turbine powerhouse they constructed on the west shore to the southern portion of Three Mile Island more than a mile away. The facility began electric generation in 1904. The construction of the “Red Hill Dam” from the east shore of Three Mile Island to the river’s east shore made York Haven Dam a complete impoundment on the Susquehanna. The pool, “Lake Frederic”, thus floods that portion of the Pothole Rocks of Conewago Falls located behind the dam. On the downstream side, water spilling over or through the dam often inundates the rocks or renders them inaccessible.
During the droughts of the early 1960s, diversion of nearly all river flow to the York Haven Dam powerhouse cleared the way for weekend explorers to see the Pothole Rocks in detail. Void of water, the intriguing bedrock of Conewago Falls below the dam greeted the curious with its ripples, cavities, and oddity. It was an opportunity nature alone would not provide. It was all because of the wall.
Smith, Stephen H. 2015. #6 York Haven Paper Company; on the Site of One of the Earliest Canals in America. York Past website www.yorkblog.com/yorkpast/2015/02/17/6-york-haven-paper-company-on-the-site-of-one-of-the-earliest-canals-in-america/ as accessed July 17, 2017.
Stranahan, Susan Q. 1993. Susquehanna, River of Dreams. The Johns Hopkins University Press. Baltimore, Maryland.
Van Diver, Bradford B. 1990. Roadside Geology of Pennsylvania. Mountain Press Publishing Company. Missoula, Montana.