Pond Boss Forums INTRO Questions & Observations sonar survey of my pond

Well, it wasn't very sophisticated or very surprising but, I finally took my Hummingbird 727 to my pond today and spent more than an hour getting depth readings almost everywhere.

I was disappointed to find only one spot where the water hit 9' - I knew it was a shallow pond but I didn't realize how much of it was only about 4' - a lot more than I realized.

Bear in mind that I've only owned this pond a short while and I rarely take my fishfinder to ponds since most of them are too shallow to be able to see much. Even with this pretty nice unit, in water less than 12' deep, you only see what is in about a 12-inch diameter circle directly under the the unit so, there's not much use.

Anyway, I drew the crude map of my pond and wrote numbers in areas where I got highly consistent readings. But, I combed practically every square foot of that place except the far back end where I can see all the way to the bottom and it's only about 2' deep all through that area.

OK, it's a 1.2mb file so, I'm just posting the link to my scanned "scratch pad". Enjoy if it interests you or inspires you.
http://aldavison.net/fishing/pondDepthSurvey5-12-2010.pdf

Oh, and by way of a "legend", the things that look like chopped broccoli are trees that stand in the pond (though none have had any leaves for many years - they are all dead) and there's a little arch thing that represents what used to be a bent tree that formed an arch - sadly, it finally broke and fell into the water. North is at the top and that's the area where the creek feeds in. The dam is at the very bottom of the page and the square is my drain box.

Is the pond at full pool now?

Well, we aren't completely sure just what water level is full pool at our pond. With all the work we did on the drain box and installing the shutters, we have the water at the level that we think is normal. I could raise it at least another foot and I think it would still be safe for the dam. But, the reason we haven't raised it is because we want to leave a margin of safety in case of a massive rain event.

I suppose your question would raise another question for me - what exactly is full pool? How does one determine that?

If my water were to rise another 3 feet from what the level is currently, it would begin to pour in over the top of the drain box (a 6' x 9' concrete structure that is completely open at the top). I've only seen it that way once - and our spillway area was running water at about a 3 inch depth. We believe that the spillway area is really intended to run only for emergencies and not normal levels. This was a 100-year flood event and our drain box was pretty much at capacity. At this event, we observed that water was only about 2 feet from over-topping the dam.

So, currently, our water level is 5-6 feet below the top of the dam. That feels right but, someday I'll get Greg Grimes to come and look...when I'm not too broke to pay him.

Al, good job. That area near the dam that drops from 5' 2" to 8+ might be
a good spot.