Flood Plain Maps and Alluvial Soils of the Preston Brook Watershed

 Flood Plain Maps and Alluvial Soils of the Preston Brook Watershed 

Looking at data for the Preston Brook watershed, it is quite a small shed, so I decided to analyze data from the surrounding larger Winooski River watershed that Preston Brook feeds into. 

Typical soils in the Winooski River watershed are deep, moderately well drained, and formed in alluvial materials. These soils are fairly coarse and silty, which makes them have fine drainage capabilities. 

The following image represents that USDA Soil Survey data for soil types in the Winooski River watershed…as we can see, the soils are primarily Adams and Windsor soils, which are loamy-sand soils (nice for drainage!). 

The history of soils in Vermont as a whole is actually quite interesting! The soil in the Champlain valley region of Vermont (and the Preston Brook watershed) are relatively young, as the glaciers that covered the state receded only about 13,500 years ago (Burlington Geographic).  The state soil of Vermont is the Tunbridge soil, which is prime for agriculture! This soil has very defined horizons, which includes a nice, thick, dark O-horizon and is made of loamy, well-drained soil (Vermont Soils). 

The well-draining aspect of the soils in the Winooski River Watershed has been beneficial for Vermont, but in the past few years has been harmful. For the last two years (to the DAY), the summers in Vermont have had periods of drought followed by extreme rain. These extreme rains have over-saturated the loamy soils of the Winooski River watershed, rendering the soils incapable of draining, and thus causing devastating flooding in the area. 

As a result of these floods, the damage estimate/future flood risk mapping of the Winooski River watershed has boomed. For example, this is a map that highlights 200 properties at risk of floods from the Winooski River over the next 30 years:

https://firststreet.org/city/winooski-vt/5085150_fsid/flood

The State website also has AMPLE flood mapping data available for its citizens: https://dec.vermont.gov/watershed/rivers/river-corridor-and-floodplain-protection/river-corridor-and-floodplain-maps. 

Works Cited

“Burlington Geographic.” Www.uvm.edu, www.uvm.edu/place/burlingtongeographic/lenses/surficial-geology.php.

NRCS. “Web Soil Survey.” Usda.gov, 2019, websoilsurvey.nrcs.usda.gov/app/.

“Vermont Soils | Natural Resources Conservation Service.” Www.nrcs.usda.gov, www.nrcs.usda.gov/conservation-basics/conservation-by-state/vermont/vermont-soils.

“Winooski, vt Flood Map and Climate Risk Report.” Firststreet.org, 2024, firststreet.org/city/winooski-vt/5085150_fsid/flood. Accessed 18 Nov. 2024.