that pond is electric only,,,go to the marine patrol website,,there is a section where you can look up restrictions on certain bodies of waters . i have a friend that fishes it quite a bit,,gets lots of brookies out of there..
Tewksbury is an amazing fishery. There are enormous Browns there, big rainbows and football-sized brookies. But very difficult to fish except for the newly stocked trout. There is so much natural food: smelt (in spring they run up the small trickle of a stream in the north end), huge population of crawfish which the big browns come into shore to feed on after dark, and great hatches of bugs including big Hexagenia. Hard to compete with all the available food in there, but it can be done with perservation -- especially just before dark. A fish finder will show huge markings among the logs on the bottom in the deep sections (over 90' deep), but getting them to hit is a challenge. I have hooked a trout there at the west end from shore fly casting so large during a late evening Hexagenia hatch that I never stopped him until he ran out all my backing and broke off. I have seen 8-10 pound trout taken out of there through the ice.
Tewksbury Pond is mentioned as one of the most challenging small trout ponds in the northeast in the classic turn of the century book, Trout, available.
That's it in Grafton. There are some very deep spots and I had heard 90' but I may be wrong. But there is deep water there...and big trout. It is worthy of some serious fishing, but the competition with all the plentiful forage and natural bait makes it tough. The crawfish are so numerous, that you can watch them scatter ahead of you in the shallows just wading in the water at dusk. And the big fish feed after dark on them.
Good luck if you try it. I know a man named Rubin Walleyes (no pun!) who specialized in fly fishing Tewksbury. His best luck was in a float tube from dusk into deep dark. He was very successful in catching trophy fish.
Have you had much luck fishing Lake Winni? It has been the slowest I can remember in 20 years for me...but then I have been focused on turkey hunting 20 mornings of the may season until I finally got my gobbler the last day of the season.