Guitar Holding Co., L.P. v. Hudspeth County Underground Water Conservation District No. 1, et al., 263 S.W.3d 910 (Tex. Sup. Ct. 2008)

(local groundwater conservation district exceed rule-making authority in grandfathering existing wells without regard to both historic amount of groundwater used and its beneficial purpose; district’s scheme for issuing permits for transfer of groundwater out of district invalid).