Blog · September 27, 2026
What Is a Drainage Swale on a Plat
A drainage swale is a shallow grassed channel the plat uses to move stormwater without a pipe.
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The easement around it keeps the grade from being filled. The flow arrow, if the plat draws one, shows which neighbor is downhill.
On the recorded sheet
Paving the swale or running a fence across the flow line is what causes the complaint after the first hard rain.
The mix-up to avoid
The swale is a grade, not a creek boundary, unless the plat also calls the lot line to the water.
Find the county map
The county GIS map is the practical place to start. Find it from the Platbookmapper directory, then treat the recorded plat and deed as the documents behind the picture.
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey.