Terra Technologies has designed and constructed a Wetland and Stream Mitigation Bank in Gasconade County, Missouri which will provide compensatory mitigation for future impacts to wetlands and streams throughout the Gasconade River watershed which includes parts of Gasconade, Osage, Maries, Pulaski, Phelps, Dent, Texas, Laclede, Wright and Webster Counties. This unique site surrounds a low-lying area bordering a shallow ephemeral channel that originates onsite and flows in two directions from its most uphill point. This unique morphology is a result of the fact that the much larger nearby Second Creek used to flow through the bank valley but abandoned that portion of its path thousands of years ago. In more recent years, this site has been in agricultural production and was likely logged for green ash lumber.
Terra Technologies recognized the potential of this site as the shallow local topography and poorly drained soils presented an opportunity to spread the water carried by the stream across a wide area through the proper placement of berms and through the excavation of the surrounding areas. Additionally, excavation and microtopography captured runoff and subsurface flows from the surrounding Ozark hills, creating additional wetlands a distance from the stream channel.
This site contains approximately 8 acres of created riparian corridor and almost 34 acres of wetlands surrounded by about 95 acres of upland prairie and forest buffers. In addition, the bank surrounds a 16.5-acre permittee-responsible mitigation site which contains notably high botanical and wetland habitat diversity.The herbaceous layer in parts of the restoration areas had a high level of diversity, but the tree layer contained only a handful of species. Additional herbaceous species have been planted and numerous tree and shrub species have been introduced to the site to drastically enhance the wooded diversity. In addition, some areas in fallow fields surrounding the low-lying area have been excavated and planted with the same diverse mixture of appropriate native wetland species.
Recently, the Gasconade River Wetland and Stream Mitigation Bank was independently verified by the Missouri Herpetological Association to sustain habitat for small-mouthed salamanders (Ambystoma texanum) and marbled salamanders (Ambystoma opacum). Small-mouthed salamanders had not been previously observed in Gasconade County and marbled salamanders had not been recorded in the county in more than 30 years. Several central newts (Notophthalmus viridescens louisianensis) have also been observed at this location. The presence of these salamanders shows that the mixture of successful upland and wetland ecosystems at this mitigation site is functioning at a high enough level to provide valuable wildlife habitat for species that need both habitat types to survive and reproduce.
Terra Technologies oversaw the construction of the site, and is currently monitoring the site. Construction was completed in 2008 and this bank was approved in 2016 by the US Army Corps of Engineers.
Contact our St. Louis office at
314-984-0050 for more information.
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