specially concurring:
I concur with the result reached by the majority. I have specially concurred to emphasize the limited statutory and constitutional issues that are before us in this appeal where the attorney general elected not to enter an appearance. This opinion addresses only section 37-92-305(11), 15 C.R.S. (1989 Supp.), and the appropriation of nontributary ground water that is not in a designated ground water basin. In my view, the water court had statutory authority to retain jurisdiction over the case pursuant to section 37-92-305(11). The water court did not, in my opinion, unconstitutionally impose a retrospective interpretation of the statute on Qualls because a final decree for a water right had not been entered. I also agree that collateral estoppel did not bar the water court from retaining jurisdiction.
Qualls applied for a permit to construct a well and on June 28, 1974, the state engineer issued the permit. The permit authorized Qualls to drill a well into the Arapahoe aquifer and to withdraw 275 acre-feet of water per year from that formation. The well was completed and on June 25, 1975, Qualls filed a statement of beneficial use of ground water with the Office of the State Engineer. Subsequently, Qualls filed an application for a replacement well permit which was granted by the state engineer on June 10, 1982. The replacement well permit also limited production from the well to 275 acre-feet per year from the Arapahoe aquifer. The replacement well was completed and Qualls filed a statement of beneficial use with the state engineer.
On December 10, 1983, Qualls filed an application for nontributary ground water that was not in a designated ground water basin and sought to perfect its right to the Arapahoe aquifer ground water covered by the 1982 replacement well permit.1 A statement of opposition was filed and the matter was referred to the water referee for Water Division 1. The parties stipulated to proposed rulings and findings of the referee and the referee accepted the rulings and findings on November 27, 1984. The water court adopted the referee’s rulings and findings as the decree of the water court on December 31, 1984. The decree provided that Qualls had a conditional water right in the amount of 275 acre-feet per year. The conditional water right was *1102continued until November, 1988 at which time Qualls would be required to make a showing of due diligence in putting the water to beneficial use or a showing that the conditional water right had been put to beneficial use and was absolute.
Effective July 1, 1985, the legislature amended the Ground Water Management Act, sections 37-90-101 to -142, 15 C.R.S. (1973 & 1989 Supp.), and set forth that nontributary ground water was not subject to the doctrine of prior appropriation. Section 37-90-102(2), 15 C.R.S. (1989 Supp.); see also section 37-92-305, 15 C.R.S. (1989 Supp.). In lieu of the prior appropriation doctrine, nontributary ground water resources “shall be allocated as provided in this article on the basis of ownership of the overlying land.” Section 37-90-102(2). In keeping with a departure from the doctrine of prior appropriation, section 37-92-305(11), C.R.S. 15 (1989 Supp.) was added to the Water Right Determination and Administration Act, sections 37-92-101 to -602, 15 C.R.S. (1973 & 1989 Supp.). Section 37-92-305(11) provides that a decree for a nontributary ground water right need not include a date of initiation of the withdrawal project and that a holder of a conditional nontributary ground water right is relieved of any duty to make showings of diligence in completing the appropriation.2
On October 14, 1988, the water court entered an order, sua sponte, relieving Qualls of the duty to show due diligence. In addition, the order provided that the water court would retain jurisdiction pursuant to section 37-92-305(11). Qualls filed a motion to amend the order to strike the provision for retained jurisdiction on the part of the water court. The water court denied the motion to amend on February 8, 1989. Qualls appealed.
Qualls contends that the water court had no jurisdiction to add a retained jurisdiction provision to the conditional decree. Alternatively, Qualls asserts that adding a retained jurisdiction provision constitutes unlawful retrospective application of the provisions of Senate Bill 5, ch. 289, 1985 Colo. Sess. Laws, 1160-69,3 that there is no “necessity” to retain jurisdiction pursuant to section 37-92-305(11), and that collateral estoppel bars redetermination of the amount of ground water that may be withdrawn annually from the well.
In my view, the retained jurisdiction provision is an acknowledgement on the part of the water court of the authority conferred upon it by the legislature to retain jurisdiction to adjust annual amounts of withdrawal of nontributary ground water which is not in a designated ground water basin or any ground water from the Dawson, Denver, Arapahoe, Laramie-Fox Hills or Dakota formations outside of a designated ground water basin as aquifer information becomes available. Sections 37-92-305(11), 37-90-137(4). The provision entered in the water court’s order does not confer upon the water court any power that it did not already possess pursuant to section 37-92-305(11). Qualls does not contend that the retained jurisdiction provisions of section 35-92-305(11) are unconstitutional and questions only the water court’s application of the statute. See section 37-82-101, 15 C.R.S. (1989 Supp.);4 *1103State v. Southwestern Colorado Water Conservation Dist., 671 P.2d 1294, 1316-18 (Colo.1983) (state has plenary authority over ground water; court does not reach issue of state’s power over existing ground water users under section 37-90-137(4) of the Ground Water Management Act). In light of the legislative intent set forth in section 37-92-305(11), Qualls’ argument that the water court lacked jurisdiction to add a retained jurisdiction provision to its 1988 order cancelling Qualls’ diligence obligations is unfounded.
The Colorado Constitution, article II, section 11 provides that “[n]o ex post facto law, nor law impairing the obligations of contracts, or retrospective in its operation ... shall be passed by the general assembly.” A law is retrospective in operation where it “ ‘takes away or impairs any vested right acquired under existing laws, or creates a new obligation, or imposes a new duty, or attaches a new disability in respect to transactions already past.’ ” Continental Title Co. v. District Court, 645 P.2d 1310, 1314 (Colo.1982) (quoting Moore v. Chalmers-Galloway Live Stock Co., 90 Colo. 548, 10 P.2d 950 (1932)). However, the water right decreed in 1984 was a conditional right to nontributary ground water from the Arapahoe aquifer that was not in a designated ground water basin. Although a conditional water right has been termed vested, Rocky Mountain Power Co. v. White River Elec. Assoc., 151 Colo. 45, 376 P.2d 158 (1962), it is vested in the sense that if the appropriator diligently puts the water to beneficial use, the appropriator is entitled to a water right to the extent, and in the amount, actually put to beneficial use with a priority date of the original conditional decree. Section 37-92-103(6), 15 C.R.S. (1973);5 Rocky Mountain Power Co. v. Colorado River Water Conservation Dist., 646 P.2d 383, 387 (Colo.1982). In a conditional decree, the priority date and the maximum amount of water that can be appropriated are final; however, the amount of water to be finally decreed and the uses for that water are conditional. See Waterman v. Hughes, 33 Colo. 270, 275-76, 80 P. 891, 893 (1905). In light of the inchoate nature of a conditional water right, the water court may attach conditions to a conditional water right to ground water described in section 37-90-137(4) as authorized by the legislature pursuant to section 37-92-305(11) without violating the constitutional provisions against retrospective operation of the law.
Qualls asserts that a water court must make a finding of necessity in order to retain jurisdiction pursuant to section 37-92-305(11). However, section 37-92-305(11) does not indicate a legislative intent to require the water court to make such a finding as a condition precedent to retaining jurisdiction to adjust the annual amount of withdrawal of ground water from wells described in section 37-90-137(4). See Schubert v. People, 698 P.2d 788, 793 (Colo.1985) (“Legislative intent is the polestar of statutory construction.”).
Finally, collateral estoppel does not bar the water court’s exercise of continued jurisdiction pursuant to section 37-92-305(11) because of the nature of a conditional water decree. See Dodo v. Fenno, 172 Colo. 294, 472 P.2d 146 (1970) (merits of conditional water right open to dispute until right becomes absolute by reason of valid final decree). Collateral estoppel does not bar relitigation of an issue that has not been finally decided. People v. Hearty, 644 P.2d 302, 312 (Colo.1982). Since the actual amount of the conditional water right remains undecided until entry of a final decree, collateral estoppel does not prevent the water court’s retention of jurisdiction pursuant to section 37 — 92—305(11) in this case.
I would affirm the order of the water court.
. Section 37-90-103(6)(a), 15 C.R.S. (1989 Supp.) provides:
"Designated ground water” means that ground water which in its natural course would not be available to and required for the fulfillment of decreed surface rights, or ground water in areas not adjacent to a continuously flowing natural stream wherein ground water withdrawals have constituted the principal water usage for at least fifteen years preceding the date of the first hearing on the proposed designation of the basin, and which in both cases is within the geographic boundaries of a designated ground water basin. "Designated ground water" shall not include any ground water within the Dawson-Arkose, Denver, Arapahoe or Laramie-Fox Hills formations located outside the boun-dries of any designated ground water basin that was in existence on January 1, 1983. The Colorado Ground Water Commission has jurisdiction to regulate the amount of annual withdrawal of designated ground water, unless the ground water is in a ground water management district. Sections 37-90-111, 37-90-130(2), 15 C.R.S. (1973 and 1989 Supp.). The board of directors of a ground water management district have the statutory authority to regulate the use of ground water within the district. Section 37-90-130(2).
Nontributary ground water is defined as “that ground water, located outside the boundaries of any designated ground water basins in existence on January 1, 1985, the withdrawal of which will not, within one hundred years, deplete the flow of a natural stream ... at an annual rate greater than one-tenth of one percent of the annual rate of withdrawal.” Section 37-90-103(10.5), 15 C.R.S. (1989 Supp.).
.Section 37-92-305(11) provides in part:
Nontributary ground water shall not be administered in accordance with priority of appropriation, and determinations of rights to nontributary ground water need not include a date of initiation of the withdrawal project. Such determinations shall not require subsequent showings or findings of reasonable diligence, and such determinations entered prior to July 1, 1985, which require such showings or findings shall not be enforced to the extent of such diligence requirements on or after said date. The water judge shall retain jurisdiction as to determinations of ground water from wells described in section 37-90-137(4) as necessary to provide for the adjustment of the annual amount of withdrawal allowed to conform to actual local aquifer characteristics from adequate information obtained from well drilling or test holes.
Section 37-90-137(4) applies to wells outside of a designated ground water basin that withdraw nontributary groundwater or any ground water from the Dawson, Denver, Arapahoe, Laramie-Fox Hills or Dakota aquifers.
. Senate Bill 5 amended sections 37-90-102, 37-90-137, and 37-92-305 in 1985.
. Section 37-82-101(1) provides in part that “[a]ll nontributary ground water shall be subject to such administration and use as the general assembly may provide by law.”
. Section 37-92-103(6) defines a conditional water right as "a right to perfect a water right with a certain priority upon the completion with reasonable diligence of the appropriation upon which such water right is to be based."