A little background. My lake is a tiny impoundment approx 50 acres. It’s long and narrow probably 3/8-1/2 mile long. There’s the main lake, the ‘narrows’ that we call it then the channel that’s also the inlet. The lake is VERY shallow average I’d say 8 feet. 
 

While out this summer getting acquainted with my SV Garmin I found the original creek bed. I kept zigzagging scanning this along a decent stretch of the main lake. It’s an average of three feet deeper than the rest. There’s no contour maps for this lake and my Garmins don’t have QuickDraw, so come spring I’m going to zigzag again and waypoint it so it’s clear as day. 
 

I don’t know squat about impoundments because they’re few and far between around here. I’m guessing this creek bed should be a good spot to target? School me on creek beds and impoundments. 
 

 

Here’s a google earth image. Up is north, the current runs from the north to the south-south east. I used the measuring tool on Google Earth and it’s about 4600’ from end to end. 

 

What river/creek was impounded to form this lake?

Dickerson creek which is a tiny creek that runs through our county. The outlet (we call it the toilet) is a 48 inch vertical culver that drains under the road to the lake you see across the road from my lake. So there is current but not much. 

River/creek channels are the lifeblood of an impoundment, it's where the lake started.

 

When looking at a topographical map I start my searches at the river/creek channels & look shallower from there.