The only thing I've ever successfully used to catch Shad with, is a cast net.
daytime - they must be schooling on the surface, or just below it
nighttime - you can find them circling under dock/pier lights, especially those that are close to the water's surface
I would suggest a minimum size of 5ft radius for the cast net ... and a mesh size of 1/4" ... monofilament mesh ... with the most weight per foot that you can afford (minimum of 1lb/foot).
Google up "bait cast net" and you'll find plenty of links for brands ... and how-to throw instructions. I bought mine from Nylon Net Company ... but, there are many other good ones out there.
Just don't forget to wrap the throw line around your wrist before throwing the net ... had a friend that forgot to do so, and threw his brand new $50 cast net right to the bottom of the lake :D
AND, of course, check with your local regulations FIRST ... to make sure it's legal to even use a cast net .. mesh size &/or radius size regulations ... or even if you can legally catch & use Shad for bait (at that lake).
... cp