Flooding and Floodplain Management

By: Joe Quatrini, Technical Team Leader
Storm events in 2018 produced record rainfall and caused unprecedented damage to infrastructure and property throughout Bradford County.  The question is, was last year an anomaly, or just a preview of things to come and a shift to a new ‘normal’?  Trends in rainfall data certainly support the latter!  As we prepare for more frequent and more intense storm events at the county level, so too should landowners.
 

What are some of the major factors that make Bradford County susceptible to storm damage?  First, unstable, unconsolidated soils throughout our landscape create easily erodible streambanks.  Much of this instability is a result of numerous glacial advances into northern PA.  The effects of repeated deposition of material from the north and erosion of the existing landscape that occurred thousands of years ago can still be seen today.  Also, much of our soil is affected by a shallow fragipan - a subsurface soil layer that restricts water flow and root penetration, typically a layer of clay or bedrock in Bradford County.  As rain falls, there is reduced soil absorption capacity and most reaches our streams and waterways as runoff instead of through infiltration and groundwater recharge.  Unstable soils and poorly rooted vegetation contribute excess gravel and debris to our waterways, which fill the channels, clog stream culverts, and cause flooding and damage to infrastructure.  Second, our network of stream crossings (pipes, box culverts, and bridges) are, for the most part, significantly undersized and unable to handle large storm flows, let alone be able to handle all the associated debris.  Third, although a rural county, Bradford has an extensive road network that interfaces with thousands of miles of streams.  Every time a road crosses or parallels a stream, there is increased risk of damage during high flow events.  Fourth, flat, low-lying areas adjacent to streams, or floodplains, are typically considered prime areas for development.  Historically, this was related to trade and transport of goods.  Currently, it may be due to ease of construction, reduced maintenance of the landscape or driveways, or other personal preferences.
 
What can landowners do to reduce the risk of flood associated damage?  First and foremost, landowners can limit development in floodplains and flood prone areas.  Whether officially designated as floodplain or just situated near a waterway, land that has the potential to flood or be damaged by stormflows, should not be developed.  Landowners should make a conscious effort to refrain from building improved structures within these areas.  Furthermore, most municipalities have enacted floodplain ordinances that regulate the type of development within floodplains, and landowners should follow them accordingly.  For existing structures in these areas, floodproofing measures can be taken.  For homes and businesses, any utilities (water heaters, furnaces, etc.) can be elevated above the 100-year flood elevation or above historic flood heights.  Additionally, although costly and labor intensive, there may be opportunity to relocate structures outside of known flood and stormwater affected areas.
 
There are many opportunities to improve the county’s resiliency after these events, including: establishing woody vegetation along stream edges (riparian zones) to stabilize streambanks and reduce erosion and debris accumulation; working with local watershed organizations and BCCD to stabilize eroding and unstable streams; maintaining and/or creating wetlands and other water retention features that may slow stormwater runoff, increase infiltration, and recharge groundwater supplies.  Remember, floodplains are called floodplains for a reason, and flooding will continue to happen, it’s just a matter of how often and to what extent.  For more information on this topic, or to learn more about making your property more flood resilient, please contact your local municipality, BCCD, or visit FEMA’s flood map service center website at https://msc.fema.gov/portal/home.
 
The Bradford County Conservation District is committed to helping people manage resources wisely.  You can visit the Bradford County Conservation District at 200 Lake Rd in Wysox across from the Wysox Fire Hall. Contact us at (570) 485-3144 or visit our web page at www.bccdpa.com.
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