“There are two things that interest me: The relation of people to each other, and the relation of people to land,” said American author and conservationist, Aldo Leopold. Since 1992, The Upper Susquehanna Coalition (USC) with its network of 19 Soil and Water Conservation Districts in New York and Pennsylvania have followed the same sentiment.
To enhance this mission of holistic land and water stewardship, the USC through Tioga County SWCD, have embarked on a Streamside Berm Removal Program. The new initiative with funds received from a NYS CFA grant for the Southern Tier, target work along the 17,000 miles of streams in the Upper Susquehanna Basin. The goal is to remove 48,000 feet of streamside berms and reconnect the streams to their floodplains.
Hold on there! “I thought a berm was good protection from flooding?”
Berm removal and natural stream design are ideas and practices that are counter intuitive to the public and deserve assessment by experienced personnel. “The berming of stream banks are sometimes the result of a post flood emergency stream response, says USC Wetland Biologist, Jeremy Waddell. We don’t condone berming as a short or long term solution.”
The USC team knows stream dynamics and how to help attenuate floods, improve water quality and diversify habitat. The old adage of “slowing it down, spreading it out and soaking it in” is a principle they follow to help landowners understand their particular situation.
“The stream needs access to its floodplain for many reasons. Because the floodplain belongs to the stream, they tend to want to use them from time to time. Berms cut off the flood water and thus cut off the inflow of fertile sediments to rejuvenate soils, said Waddell. From an agricultural standpoint, these deep fertile sediments deposited by occasional flooding are what make those lands so great for crops. As we all know, it’s a process that has been functioning perfectly fine for millions of years.”
Streamside berms serve as an impediment for the stream to spread itself out during flood events. The result of channelizing streams and not allowing access to natural floodplain areas exacerbates the effect of flooding downstream neighbors.
After many of the recent flooding events across the watershed, many streams have required some maintenance to re-establish flow. In many cases, the spoil materials generated from this type of maintenance activity is cast on the stream bank and not removed. This type of streamside material can be very detrimental to stream corridors and can have a lasting affect after the flood is forgotten.
The streamside berm consists mostly of course gravel that is unsuitable for many native species of trees and shrubs to grow. Subsequently, mostly undesirable or invasive species such as Japanese Knotweed, take root and are difficult to eradicate once established. Additionally, the loose gravel is highly erodible and can be re-mobilized in future flooding events.
The linear gravel spoil piles are often piled up around healthy trees in the riparian zone. Over time, the trees will die as a result of material accumulated at their base. The resulting loss of canopy cover in the riparian area allows sunlight to reach the stream and can increase water temperature making the stream unsuitable for cold-water organisms and fish. In addition to providing shade for streams, the tree roots hold stream banks in place and prevent erosion. With the loss of canopy cover in the stream corridor, stream bank erosion and channel migration is likely to occur.
“From a hydrography standpoint, the longer floodwaters remain on the land especially in the headwaters, the peak discharges are slowed down and re-enter the system at a slower rate. This slowing benefits the family or farm downstream, said Waddell. This means slower and lower water passing by when it rains hard. If the stream has a chance to spread out, it will, and that’s good for everybody.”
The berm removal program will target counties impacted by Tropical Storm Lee and Sandy. It will provide high stream flows, access to the floodplain during major storms, where the damaging power of concentrated stream flow will be attenuated. With the advent of continuing climate change and larger, more frequent rainfall events, there is need to ensure watersheds can function correctly by implementing projects that address stormwater concerns.
Since the USC has a long tradition of working collaboratively with private landowners to deliver best management practices on land and water, the USC is actively seeking individuals and businesses that are interested in participating in our Streamside Berm Removal Program or having a site evaluation by a seasoned professional.
The program is at no cost to landowners and the gravel is yours to keep elsewhere, or we can haul it away. If interested please call Jeremy Waddell at 607-972-5098 or email firstname.lastname@example.org .