Hi PJB, if it were me I would remove the smaller tree grouping,but only because I like trees. I would suggest that on the larger tree grouping you had marked, if you keep them, you remove trees back say a 30 to 50ft back from the shoreline for less tree debris in the pond and easier soil,grass,etc. management.

Looks like a great place to build what looks like a great dream pond.
A few questions would be how big is the current pond, how large is the pond you will build? What are your goals for the pond. Are you going to manage the pond or just let nature take it's course? Will it be for mostly swimming and such or for fishing primarily? Will you feed and or aerate? Are you planning on bedding areas and structure or just a smooth bottom with little or no contours?

With the long dam you have drawn, IMHO,I would be real particular in it's construction. A high quality core and quality clay dam would save tons of headaches and additional to prevent a leak rearing it's ugly head. The pond bottom would need quality clay liner in 3 or 4, 3" to 5"lifts each packed and laced into the dam area IMHO. Will assume you have read of the many problems fellow PB'ers have had with small leaks, seeps, large leaks and even worse case dams breached. Bob Lusk's book on "A perfect Pond" would be a good start, if your back ground is not in pond construction and management.

My pond is not visible from the road and I like that, although I have still had uninvited company a couple of times. I have three trees at the shore line and plan on removing two of the three because of limb and leaf debris that drops into the pond.

Since you said your property is flat,and leads to the assumption that the pond will receive little runoff(?), are you planning on a well, or is there an existing well for water level control? Does the area you live in receive lots of rain?

IMO, since you are planning a home as well, limited tree cutting, other than the strip around the pond I was discussing above might warrant waiting until you have everything built and look at it from where you build your house. I say that because it only takes a few minutes to cut down a tree and so long to grow one back you wish you would have kept,IMHO.

Good luck and let us know what you decide to do.

Life is more fun with a pole in your hand.