Baccharis Consulting LLC

Water Inundation in White Clay Creek Watershed, Delaware (2002-2017)

 

Picture of White Clay Creek

                                             White Clay Creek at Red Mill Park

Discussion of White Clay Creek Watershed

White Clay Creek is a tributary of the Christina River and is not often thought of having tide since it is mostly a Piedmont drainage.  The tidal section runs from its confluence with the Christina River to north of Churchmans Marsh near Stanton, Delaware.  Most of the tidal area is highly disturbed by exotic invasive plant species and ditching.  More information on the watershed can be found at this link.

The tidal exposure is similar to the Christina River in miniature but even smaller than Brandywine Creek.  But like the others, it is a riverine watershed.  This means that precipitation events have an outsize influence on the inundation numbers.  For instance, you can have a heavy rainfall event in the upper parts of White Clay Creek and have the water flow in the tidal sections and have nowhere to go but up.  There is not enough area for the water to spread out.  In these watersheds (riverine) it is best to look at the trends rather than the actual numbers.

White Clay Creek Water Inundation

(2002-2017)

Table 1. White Clay Creek Watershed Tidal Water (2002-2017) in acres
Year Estuarine Tidal Riverine Water
2002 33.60
2007 35.06
2012 40.14
2017 36.16

ETRW = Estuarine Tidal Riverine Water (Salinity < 0.5 ppt)

Table 1 shows that the amount of tidal water in the watershed has risen overall since 2002 with a marked regression in the 2012-2017 time period.  The overall rise is likely due to sea level rise and the regression could possibly be due to sedimentation or precipitation events or a lack thereof.

Table 2. Average Rate of White Clay Creek Watershed Tidal Water Inundation 

(2002-2017) in acres/year

2002-2007 +0.29
2007-2012 +1.02
2012-2017 -0.80

Table 2 shows a fluctuating inundation rate for this watershed.  This seems to be a typical behavior of a riverine watershed.  Unlike a lot of other watersheds, it did not experience the “2007-2012” slowdown in rise.

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