Any spots in lewisville or G-Vine that I can target for Grass Carp?

Not really. They are not native fish and usually only end up in lakes accidentally unless they have been stocked with permission from Texas Parks and Wildlife.

Unless they are in a lake permitted by Parks and Wildlife, they are supposed to be killed instead of being released back into the lake. If permitted by Parks and Wildlife, they are to be returned unharmed to that lake.

I guess from some of the other threads Austin has lakes with Grass Carp in them

Some golf course ponds around the state have them. I saw some huge ones just hanging on the surface in Frisco a few years back and wished I had an egg sinker and treble hook.

Lake Austin has plenty but is catch and release only. Also Purtis Creek , again catch and release only.

Thx for the info guys, I was going to try and catch a common carp and grass carp. I have some friends from Europe that is interested in catching the 2 types. I have a feeling they are not fans of catch and release

Not that I know a lot about it...but my farm landlord is from the UK and his brother is an avid carper. I've also had fishermen from the UK at some of the lakes I manage. At least the guys from the UK do catch and release, I could hardly make them toss the unwanted carps from my lakes out they wanted to put them back so.

If fishing for grass carp you need to be aware of the regulations for the particular water body you are fishing in. Some require catch and release while others require immediate evisceration. Big difference between the two and it is by water body (lake, pond, stream, etc.) Do it wrong and risk a steep fine.

Purtis Creek has common and grass, they are trying to remove the grass carp.