In 1994, Ps bought 381.40 acres on which to grow oats and peanuts and graze cattle. The land overlies the Edwards Aquifer, 'an underground layer of porous, water-bearing rock, 300-700 feet thick, and five to forty miles wide at the surface, that stretches in an arced curve from Brackettville, 120 miles west of San Antonio, to Austin.' A well drilled in 1956 had been used for irrigation through the early 1970s, but its casing collapsed and its pump was removed sometime prior to 1983. The well continued to flow under artesian pressure, and while some of the water was still used for irrigation, most of it flowed down a ditch several hundred yards into a 50-acre lake on the property. The lake was also fed by an intermittent creek. Much of the lake water came from the well. Ps' predecessors had pumped water from the lake for irrigation. The lake was also used for recreation. To continue to use the well, or to drill a replacement Ps needed a permit from D. D had been created in 1993. The Act that created D 'prohibits withdrawals of water from the aquifer without a permit issued by D.' With few exceptions, water may not be withdrawn from the aquifer through wells drilled after June 1, 1993. A user's total annual withdrawal allowed under an 'initial regular permit' (IRP) is calculated based on the beneficial use of water without waste during the period from June 1, 1972, to May 31, 1993. Beneficial use is defined by 'the use of the amount of water that is economically necessary for a purpose authorized by law when reasonable intelligence and reasonable diligence are used in applying the water to that purpose.' A user's total permitted annual withdrawal cannot exceed his maximum beneficial use during any single year of the historical period, or for a user with no historical use for an entire year, the normal beneficial use for the intended purpose. Ps applied for authorization to pump 700 acre-feet of water annually for irrigation. Ps' request was based on two acre-feet for the total beneficial use of irrigating the 300 acres plus the recreational use of the 50-acre lake. In December 1999, D approved Ps' request to amend his application to move the point of withdrawal from the existing well to a replacement well to be drilled on the property. Ps proceeded to drill the replacement well at a cost of $95,000. In November 2000, D notified Ps that their application would be denied because 'withdrawals from the well during the historical period were not placed to a beneficial use.' The matter was transferred to the State Office of Administrative Hearings. The prior owner testified that in 1983 and 1984, an area totaling only about 150 acres had been irrigated, that this had been done using an agricultural sprinkler system that drew water from the lake, and that no more than seven acres had been irrigated with water directly from the well. The administrative law judge concluded that water from the lake, including the well water that had flowed into it, was state surface water, the use of which could not support Ps' application for groundwater, and that the recreational use of the lake was not a beneficial use as de fined by the Act. Ps were to be should be granted an IRP for 14 acre-feet of water. D agreed. Ps appealed and sued D for taking his property without compensation in violation of article I, section 17(a) of the Texas Constitution. The court granted summary judgment for Ps concluding that water from the well-fed lake used to irrigate 150 acres during the historical period was groundwater and that Ps were entitled to an IRP based on such beneficial use. The court granted summary judgment for D on all of Ps' constitutional claims, including his takings claim. Both parties appealed. The court of appeals agreed with D that groundwater from the well became state surface water in the lake and could not be considered in determining the amount of Ps' IRP. The court affirmed D's decision to issue a permit for 14 acre-feet. It then held that 'landowners have some ownership rights in the groundwater beneath their property . . . entitled to constitutional protection ' and therefore Ps' takings claim should not have been dismissed. Both parties appealed.