Where in Sichuan is 虾 pronunced ha1 (xa⁵⁵)?
It does not exist any more in Chengdu dialect (my mother's tongue), but I think if you regard Chongqing dialect as a part of Sichuanese, there must be somewhere.

The only usage of 'ha' in Chengdu dialect is in 蛤蟆 but it is ha2, and it does not seem to be a native word in Sichuanese but imported from Standard Chinese. We traditionally use 赖克宝 instead.

The dialects in some place in Chongqing sometimes pronounce 解决 as gai3 jio2. And I believe that this is because they mostly keep the original dialect inherited from Hubei/Hunan dialect. So 虾 must be pronounced as ha1 there.