994 So.2d 314 (2008)
VALLADARES
v.
STATE.
No. 2D08-520.
District Court of Appeal of Florida, Second District.
November 5, 2008.
Decision without published opinion. Affirmed.


925 P.2d 918 (1996)
144 Or. App. 106
STATE of Oregon for the Use and Benefit of Richard L. CIPRIANO, dba Rich & Assoc. Construction Co., Plaintiff,
v.
TRIAD MECHANICAL, INC., an Oregon corporation, Defendant-Appellant, and
Reliance Insurance Company, a Pennsylvania corporation, Defendant, and
State of Oregon, By and Through its Department of Fish and Wildlife, Respondent.
TRIAD MECHANICAL, INC., an Oregon corporation, Appellant,
v.
STATE of Oregon, By and Through its DEPARTMENT OF FISH AND WILDLIFE, Respondent.
9306-04234; CA A84922.
Court of Appeals of Oregon.
Argued and Submitted April 21, 1995.
Decided October 16, 1996.
Review Denied December 24, 1996.
*919 Rodney R. Mills, Portland, argued the cause for appellant. With him on the briefs was Seifer, Yeats & Mills.
Richard D. Wasserman, Assistant Attorney General, argued the cause for respondent. With him on the brief were Theodore R. Kulongoski, Attorney General, and Virginia L. Linder, Solicitor General.
Before WARREN, P.J., and EDMONDS and ARMSTRONG, JJ.
WARREN, Presiding Judge.
Triad Mechanical, Inc., appeals from a judgment dismissing its breach of contract and quantum meruit claims against the Oregon Department of Fish and Wildlife (ODFW). Before trial, the court granted ODFW's motion under the parol evidence rule to exclude evidence of anything intended to contradict the terms of a written contract and change orders signed by ODFW and Triad. The trial court also ruled that two change orders constituted an accord and satisfaction *920 between ODFW and Triad. Those rulings effectively precluded Triad from presenting evidence to support its claims. The court then granted ODFW's motion to dismiss Triad's claims and entered a judgment under ORCP 67 B. We affirm.
Triad contends that the trial court erred in the following three particulars: (1) in holding that the parol evidence rule barred evidence of discussions that the parties allegedly had before signing the two written change orders; (2) in holding that the change orders constituted an accord and satisfaction; and, (3) in granting ODFW's motion to dismiss.[1] We affirm.
Triad and ODFW entered into a written contract to construct improvements to the Oak Springs Fish Hatchery. The contract required Triad to complete the improvements in 335 days. Rich & Associates Construction Company, a subcontractor to Triad, agreed to perform a portion of the project involving rock excavation.
The contract between Triad and ODFW specified that 100 cubic yards of rock were to be excavated and provided that any rock excavation in excess of 100 cubic yards would be a change to the contract. The contract gave Triad a claims procedure to pursue equitable adjustments to the contract for changed conditions. As relevant, Article 27 of the contract provides that ODFW's engineer would
"promptly investigate the conditions, and if he finds that such conditions do so materially differ [from those specified in the contract] and cause an increase or decrease in the cost of, or the time required for, performance of this Contract, an equitable adjustment shall be made and the Contract modified in writing accordingly. * * * Adjustment for such conditions shall be made in accordance with Article 28 of [the Contract]."
Article 28 provides, in turn, that equitable
"[a]djustments for changes or changed conditions covered in Article 26 and 27 will be made on the basis of agreement of the parties: Provided, that if the parties fail to agree on the amount of an increase in the cost of performance of the Contract, the adjustment shall be on the basis of force account * * *." (Emphasis in original.)
In mid-March 1992, Rich encountered rock in excess of 100 cubic yards. On March 25, 1992, representatives of Triad, Rich and ODFW met to discuss changes to the contract required by the excess rock.
The parties disagree as to the result of the meeting. According to Triad, the parties agreed that ODFW would pay Triad a fixed unit price, ranging from $7 to $226.26 per cubic yard, for the direct cost of removing the additional rock, depending on the type and depth of the rock to be excavated. Triad asserts that the parties decided to postpone consideration of additional compensation for time and expense resulting from the extra excavation work because the total amount of those costs could not be determined at the time of the meeting.[2] Triad asserts that the parties understood that those costs would be pursued as a separate claim on completion of the project. ODFW contends that all the terms of the parties' agreement with respect to the extra rock excavation are contained in two written change orders, which ODFW prepared, signed and sent to Triad for its signature in June and August 1992. Thus, ODFW maintains that the evidence supporting Triad's assertions constitutes evidence of an oral agreement, proof of which is barred by the parol evidence rule because the change orders constitute either a completely or partially integrated agreement.
The written change orders, numbered 4 and 6, specified the costs per cubic yard for the additional rock excavation.[3] In addition, *921 each stated that "the completion time [for the project] will not increase and [will] remain at 335 days as a result of this change order." There is no mention in the change orders of an agreement that another claim would be submitted for the delay and impact costs associated with the extra excavation or, put another way, that the change orders reflect only the parties' agreement regarding the direct costs of the extra rock removal. Upon receipt, Triad promptly signed and returned the change orders to ODFW.
Triad completed the project on January 5, 1993, 52 days after the completion date specified in the contract of November 15, 1992. On January 7, 1993, it presented a claim to ODFW for the delay and impact costs associated with excavating the extra rock. ODFW refused to pay the claim, asserting, inter alia, that Triad had waived further claims for costs incurred as a result of the extra rock excavation when it signed change orders 4 and 6. Rich thereafter filed an action against Triad and ODFW on the subcontract between Rich and Triad. Triad, in turn, filed cross-claims against ODFW for breach of contract, seeking to recover the delay and impact costs allegedly incurred by Triad as a result of the additional excavation.
Before trial, ODFW filed a motion, based on the parol evidence rule, "for a ruling precluding [Triad and Rich] from entering any evidence or making reference in the presence of the jury to anything intended to contradict the terms of the written contract and change orders." That motion sought to exclude evidence of the discussion that Triad alleges the parties had at their March 25 meeting.
After reviewing the change orders, the trial court granted ODFW's motion to limit evidence. The trial court also ruled that change orders 4 and 6 constituted an accord and satisfaction between the parties. Triad told the court that those rulings effectively precluded it from presenting evidence necessary to prove its claims. Triad then sought to introduce evidence of the facts surrounding the March 25 meeting to show that the change orders did not encompass all of the terms that the parties had agreed upon.
After the offer of proof, ODFW moved to dismiss Triad's claims and, in the alternative, for summary judgment.[4] The trial court granted ODFW's motion and entered judgment under ORCP 67 B dismissing Triad's cross-claims against ODFW for breach of contract on the ground that there was no genuine issue as to any material fact and that ODFW was entitled to judgment in its favor of as a matter of law.[5]
Triad first assigns error to the trial court's grant of ODFW's motion to limit evidence under the parol evidence rule.[6] The parol evidence rule is found in ORS 41.740, which provides, as relevant:
"When the terms of an agreement have been reduced to writing by the parties, it is to be considered as containing all those terms, and therefore there can be, between the parties and their representatives or successors in interest, no evidence of *922 the terms of the agreement, other than the contents of the writing, except where a mistake or imperfection of the writing is put in issue by the pleadings or where the validity of the agreement is the fact in dispute. However this section does not exclude other evidence of the circumstances under which the agreement was made, or to which it relates, as defined in ORS 42.220, or to explain an ambiguity, intrinsic or extrinsic, or to establish illegality or fraud."
The Oregon Supreme Court "has recognized that a literal reading of ORS 41.740 would `exclude any parol evidence of the terms of an agreement once that agreement has been reduced to writing by the parties.'" Abercrombie v. Hayden Corp., 320 Or. 279, 286, 883 P.2d 845 (1994) (quoting Hatley v. Stafford, 284 Or. 523, 526 n. 1, 588 P.2d 603 (1978)). The court does not interpret ORS 41.740 as having that effect, however, and, instead, treats it as a codification of the common-law parol evidence rule.[7] The rule is a rule of integration. It prohibits oral evidence of those aspects of the bargain that the parties intended to memorialize in the writing.[8]Caldwell et ux v. Wells, 228 Or. 389, 395, 365 P.2d 505 (1961). If the parties did not intend the writing to represent their entire agreement, the agreement is only partially integrated, and prior consistent additional terms not evidenced by the writing may still form part of the entire agreement. Siegner v. Interstate Production Credit Assn., 109 Or.App. 417, 425, 820 P.2d 20 (1991). An oral agreement is not integrated in a contemporaneous writing if it is not inconsistent with the written agreement and is "such an agreement as might naturally be made as a separate agreement by parties situated as were parties to the written contract."[9]Hatley, 284 Or. at 535, 588 P.2d 603.
In analyzing a parol evidence issue, we must determine whether the agreement that the parties have reduced to writing is integrated and, if so, to what extent. ORS 41.740; Abercrombie, 320 Or. at 287, 883 P.2d 845. Although that inquiry presents issues that are both factual and legal, they are issues for the court rather than for the trier of fact. See Abercrombie, 320 Or. at 287-89, 883 P.2d 845.
In this case, the parties agree that the writings, the two change orders, are integrated. Neither party disputes that the change orders bound ODFW to pay set amounts per cubic yard for rock excavation that exceeded the 100 cubic yards specified in the original contract. Therefore, the change orders were the parties' final expression, at least with regard to those terms. See Abercrombie, 320 Or. at 288, 883 P.2d 845 (integration found where parties agreed that writings were final as to their terms but disagreed about the meaning of those terms). The scope of the duties and obligations encompassed by an integrated writing turns on an examination of the parties' intent. A writing is only as complete as the parties intended it to be.
With regard to the question of whether the writings are completely or partially integrated, we review the trial court's findings of historical fact for any evidence to support them and its legal conclusions based *923 on those facts for errors of law. See Wescold, 120 Or.App. at 519-20, 852 P.2d 960.
At this point, ODFW raises two arguments. First, ODFW argues that Triad's oral evidence is inadmissable under the parol evidence rule, whether the change orders are fully or only partially integrated, because the terms of the alleged oral agreement are "inconsistent" with an express term found in both change orders. See Abercrombie, 320 Or. at 288-91, 883 P.2d 845 (providing that the court need not address the question of whether an integrated writing is completely or partially integrated after finding that the asserted parol evidence is inconsistent with an express term of the writing). Second, ODFW argues that the change orders are not a partial integration of the parties' agreement, because the alleged oral agreement is so closely connected to the matters actually addressed in the integrated writings that it would not have been natural for the parties to have omitted those terms. We agree with both arguments.
In determining whether the parties intended the integrated writing to be a complete or partial integration, we consider all relevant evidence, including the writings and the surrounding circumstances. Abercrombie, 320 Or. at 289, 883 P.2d 845. Our task is to decide whether the historical facts are susceptible of only one reasonable interpretation. Wescold, 120 Or.App. at 520, 852 P.2d 960.
Our inquiry begins with an examination of the writings because the parties' intent often appears from the writings themselves. And, when the writing is complete on its face, we presume that the parties intended the writing to be a complete integration. Hatley, 284 Or. at 535, 588 P.2d 603. On this point, the Supreme Court in Hatley explained:
"[T]he apparent completeness and detail of the writing itself may lead the court to conclude the parties intended the writing to be a complete integration of their agreement.
"[W]hen the writing is complete on its face, [the court] should admit evidence of consistent additional terms only if there is substantial evidence that the parties did not intend the writing to embody the entire agreement." 284 Or. at 535, 588 P.2d 603 (citations omitted).
In this light, an integration clause in a writing is an indication that the writing was intended to be a complete integration, but it is not conclusive. Howell v. Oregonian Publishing Co., 82 Or.App. 241, 245, 728 P.2d 106 (1986), mod. 85 Or.App. 84, 735 P.2d 659, rev. den., 303 Or. 699, 740 P.2d 1212 (1987).
Turning to ODFW's first argument, a prior agreement is "inconsistent" with the terms of an integrated writing if it contradicts or negates an express term in the writing. Abercrombie, 320 Or. at 289, 883 P.2d 845. In Triad's offer of proof, its project manager testified, in part, that the parties orally agreed, before signing the change orders, that, on completion of the project, Triad would submit a separate claim for the additional time it would take Triad to complete the project due to the extra excavation work. ODFW maintains that that evidence negates the express statement in both change orders providing that "the completion time [for the project] will not increase and [will] remain at 335 days as a result of this change order."
In Triad's offer of proof, its project manager repeatedly testified that Triad did not ask for additional time to complete the project because it could not quantify the extra work, and, thus, it could not determine the impact of the additional work on the project schedule. He testified that ODFW agreed that Triad could submit a claim for extended project costs after the project conclusion, when the exact costs would be known. It follows then, Triad contends, that the language in the change orders means only that the State did not agree, at that time, to extend the project completion date. We are not persuaded. The language in the change orders is unambiguous, and Triad does not argue that there is an ambiguity present. The change orders unconditionally provide that the project completion would not be extended due to the extra excavation work. We conclude, therefore, that evidence of the asserted oral agreement that Triad could extend the project duration specified in the contract *924 and both change orders, and, later, pursue a claim for the costs associated with that additional work, is inconsistent with an express term of the writing. The trial court ruled that there was a complete integration and excluded that evidence.
As we understand it,[10] however, Triad also argues that the parties' oral agreement encompassed a claim for the impact or additional costs associated with the additional work that Triad conducted within the 335 days specified for the completion of the project, and that, therefore, the change orders were only partially integrated. ODFW responds that, even so, the alleged oral terms are encompassed by the change orders.
To restate the legal standard briefly: we review the question of whether the parties intended that the writing be completely or partially integrated by looking at whether the asserted oral term is such that the parties, under the circumstances, might naturally have omitted it from the writing.[11]Hatley, 284 Or. at 533, 588 P.2d 603. We look first to the writing, however, and presume that it is intended to be a complete integration. Id. at 535, 588 P.2d 603. Evidence of consistent additional terms is only admitted where there is substantial evidence that the parties did not intend that the writing embody the parties' entire agreement. Id.
The change orders, on their face, are complete. There is no mention that the listed costs are limited to the direct costs of the rock removal, nor do they mention that additional claims for the "impact" costs will be submitted later, at the project conclusion, when they will be known. Triad points to the fact that the change orders do not contain integration clauses as evidence that the parties did not intend that the writings embody all of the terms of their agreement. That, however, is not a dispositive indicator of the parties' intent, and, thus, the mere absence of an integration clause is insufficient to rebut the presumption of complete integration. Triad also relies on the testimony of its project manager that he did not intend, by signing the change orders, to resolve anything but the question of the direct costs of the additional excavation. That evidence is also insufficient to rebut the presumption of complete integration. Under the circumstances there are several facts that lead to the conclusion that the alleged oral terms were not the type that the parties might naturally have omitted from the change orders. This was a sophisticated business transaction and, when considering the surrounding circumstances, we are aware of the fact that parties with business experience are more likely to reduce their entire agreement to writing than parties without such experience. Hatley, 284 Or. at 534, 588 P.2d 603. That is the case here. Specifically, Article 27 of the contract expressly provides that any modification "in the cost of, or the time required for, performance of [the] Contract" must be in writing. Moreover, Triad's project manager testified that he was familiar with the change order procedure because he had done business with the State in the past. We find nothing in the testimony of Triad's project manager to indicate that he was unaware of the consequences of failing to put the whole agreement in the change orders. Rather, he repeatedly testified that (1) he knew that the additional excavation would require additional time, additional cost, or both; (2) he discussed those requirements *925 with ODFW; (3) he did not ask for additional time to complete the project at the March 25th meeting or at the time he signed either of the two change orders; and, (4) he did not make note of those requirements on the change orders nor did he attempt to clarify that the change orders only covered the direct costs of the additional excavation when he signed them. Under these circumstances, we conclude that the subjects addressed in the alleged oral agreement were within the contemplation of the parties, and, thus, that it would not have been natural for the parties, situated as they were, to have omitted them from the writings. Put another way, the matters of additional time and additional costs are so interrelated and connected to the main purpose of the change orders that it would not have been natural for the parties to have regarded them separately and not include them in the change orders. The writings taken together are completely integrated.
In summary, we hold that the terms of the alleged oral agreement are inconsistent with the integrated writings and, to the extent that Triad asserts a claim for compensation in addition to its claim for additional time, all of the terms that Triad alleges the parties discussed were within the scope of the writings. Additionally, the alleged oral agreement was so closely connected in subject matter to the agreement that was reduced to writing that it would not be natural, given the provisions of Articles 27 and 28, to fail to address in writing the claims now made. Consequently, we hold that the trial court did not err in granting ODFW's motion under the parol evidence rule. We therefore affirm the judgment in favor of ODFW on Triad's first, second and third cross-claims.
Affirmed.
ARMSTRONG, Judge, dissenting.
The majority concludes that the parol evidence rule bars Triad from seeking to prove its claim for indirect and delay costs for removing rock in excess of the amount specified in the parties' original construction contract. It reaches that conclusion on the ground that the change orders that addressed the direct cost of removing that rock would have addressed Triad's right to seek indirect and delay costs for that work if the parties intended such a right to survive execution of the change orders.
The majority is wrong. Given the terms of the original contract, there was no reason for the parties to believe it necessary to include language in the change orders to preserve Triad's right to seek a further contract adjustment for additional rock removal costs. That right existed in the original contract, so there was no reason to mention it in the change orders. Therefore, the contractual right that Triad seeks to enforce is not one that would naturally have been included in the change orders and, hence, it is not one that the parol evidence rule bars Triad from seeking to prove.
Article 27 of the original contract provides the mechanism by which equitable adjustments to the contract are to be made to address conditions that differ from those specified in the contract. The article provides that the Oregon Department of Fish and Wildlife's engineer will
"promptly investigate the conditions, and if he finds that such conditions do so materially differ [from those specified in the contract] and cause an increase or decrease in the cost of, or the time required for, performance of this Contract, an equitable adjustment shall be made and the Contract modified in writing accordingly. * * * Adjustments for such conditions shall be made in accordance with Article 28 of [the Contract]."
Article 28 provides, in turn, that equitable
"[a]djustments for changes or changed conditions covered in Article 26 and 27 will be made on the basis of agreement of the parties: Provided, that if the parties fail to agree on the amount of an increase in the cost of performance of the Contract, the adjustment shall be on the basis of force account * * *."
Under those provisions, the parties envisioned that changed conditions would lead to changes in the original contract by negotiated agreement. If the parties failed to reach such an agreement with regard to an increase *926 in the cost of the contract, there was a mechanism to address that failure.
Consistent with those provisions, the parties negotiated an agreement on the increased direct cost of removing the additional rock that Triad had encountered. According to Triad's evidence, they postponed trying to reach agreement on all of the consequences of the additional rock excavation, because they could not reasonably determine at that time what they would be. There was no reason to recite that fact in the change orders, however, because the original contract already provided that further adjustments could be made by agreement. In fact, if the parties had intended the change orders to foreclose any right of Triad to seek a further adjustment for rock excavation beyond the direct excavation costs stated in the change orders, they would have had to say that in the change orders, because the original contract gives Triad the right to seek such an adjustment.
The change orders confirm that understanding. They simply recite the changes that the parties had agreed to make; they do not state that the parties had agreed that there would be no further changes as a result of the additional rock excavation.
Moreover, contrary to the majority's suggestion, see 144 Or.App. at 115-116, the statement in the change orders about maintaining the original 335-day contract term supports my interpretation of the change orders. Each change order states that the "completion time will not increase and [will] remain at 335 days as a result of this change order." All that means is that the change orders do not change the completion time under the contract, which is to say that the parties have not agreed to change the completion time as a result of the additional rock excavation. Significantly, however, the change orders do not say that the parties have agreed that the additional rock excavation will not result in a change in the completion time of the contract. That means that the change orders affect only what they addressed, which is the parties' agreement about the direct cost to remove the additional rock. Any other effect of the additional rock excavation is subject to adjustment under the terms of the original contract.
Of course, the parties never reached an agreement about those effects beyond the agreement embodied in the change orders. The department sought summary judgment below on the ground that the parties' failure to reach agreement about additional costs due Triad for rock excavation precluded recovery of those costs. The trial court denied that motion, however, and the department does not challenge that ruling on appeal. Consequently, we need not decide whether Triad can prevail on its claims in the face of the department's rejection of Triad's effort to obtain a further equitable adjustment for the indirect delay and costs of the additional rock excavation.
Because of its decision on the parol evidence issue, the majority does not reach the alternative ground on which the trial court dismissed Triad's claims, which is that the change orders constitute an accord and satisfaction of the parties's dispute over the additional rock excavation. An accord and satisfaction occurs when a debtor tenders a payment on the condition that the creditor accept it in discharge of an unliquidated debt, and the creditor accepts the payment on that condition. Fiedler v. Bowler, 117 Or.App. 162, 165, 843 P.2d 961 (1992).
At the time the parties executed the change orders, there was no disputed claim or unliquidated debt. The contract was executory. The change orders merely addressed certain terms under which the parties had agreed to continue performance of it. Under those circumstance, the department was not a debtor on an unliquidated debt that the change orders discharged. See Fiedler, 117 Or.App. at 165, 843 P.2d 961. Consequently, the change orders cannot constitute an accord and satisfaction.
If the foregoing issues are addressed in the manner that I believe that they should be, it follows that the trial court erred in granting summary judgment to the department on Triad's claims. Therefore, I respectfully dissent from the majority's decision to affirm the dismissal of Triad's claims.
NOTES
[1]  Triad does not make any argument concerning its quantum meruit claim and we do not address it.
[2]  In its brief, Triad characterized these costs as "delay and impact" costs.
[3]  Change order 4 stated a rock excavation cost of $700 per cubic yard for a portion of the excavation, which was a typographical error by ODFW. It also provided a list of estimated quantities of rock to be removed under the terms of the change order, according to the rock type and depth. Change order 6 changed the $700 unit price to $7 per cubic yard and adjusted the estimated rock quantities to reflect the final quantities of rock that were actually removed. Because the actual quantity of rock removed was more than what the parties originally estimated in change order 4, change order 6 also provided for a 32.4 percent increase in the cost of the additional excavation work.
[4]  ODFW had previously moved for summary judgment on Triad's breach of contract claim on the ground that ODFW had complied with the equitable adjustment procedures specified under the contract. That motion was denied and that denial is not at issue on appeal.
[5]  The judgment also dismissed ODFW's first counterclaim against Triad for liquidated damages and awarded ODFW costs and disbursements against Triad. Rich's claim against Triad based on the additional rock excavation was abated pending the conclusion of this appeal.
[6]  We do not address Triad's assignment that the trial court erred by ruling that the change orders constituted an accord and satisfaction. That does not raise a new or different issue from the one we resolve here. Triad's claim is for breach of contract and our ultimate inquiry goes to the scope of the parties' agreement: whether the evidence of an alleged oral agreement is properly admissible to vary or supplement the terms of the parties' written agreement. An accord and satisfaction is a type of executed, substituted contract. Lenchitsky v. H.J. Sandberg Co., 217 Or. 483, 490, 343 P.2d 523 (1959). To determine whether the agreement should be characterized as an accord and satisfaction does not help us to resolve the question regarding the scope of the parties' agreement.
[7]  Despite its name, the parol evidence rule is a substantive rule, not a rule of evidence. It "`does not exclude certain data because they are * * * untrustworthy or undesirable means of evidencing some fact to be proved[;] * * * [rather,] it declare[s] that certain kinds of fact are legally ineffective in the substantive law.'" Abercrombie, 320 Or. at 286, 883 P.2d 845 (quoting 9 Wigmore, Evidence § 2400 (Chadbourn rev 1981)). That follows from the rule's purpose, which is to promote commercial certainty by allowing contracting parties to rely on the final written expression of their agreement as embodying the terms of the agreement. Id.; Wescold, Inc. v. Logan International, Ltd., 120 Or.App. 512, 518-19, 852 P.2d 960 (1993), rev. den., 318 Or. 459, 871 P.2d 123 (1994).
[8]  The parol evidence rule, however, does not prohibit a party from introducing evidence extrinsic to a writing to explain an ambiguity in the writing, even if the writing is completely integrated. ORS 41.740 ("this section does not exclude other evidence * * * to explain an ambiguity"); see Abercrombie, 320 Or. at 291, 883 P.2d 845, and cases cited therein. Triad does not argue that the terms of the change orders are ambiguous.
[9]  Triad does not contend that the oral agreement was supported by a separate consideration.
[10]  During its offer of proof, Triad presented evidence of its delay costs. Triad's project manager testified that its claims included costs for additional manpower and lost productivity that it incurred both before and after the specified completion date of November 15, 1992. It is not clear from the record, however, just how much Triad is claiming for the costs that it incurred for the additional 52 days that it took to complete the project. First, Triad submitted a summary of its claims against ODFW: $81,819 for extended project support; $140,430 for productivity loss/impact; and $15,600 for retainage/contract balance. There is no dispute that Triad completed the project 52 days behind schedule. However, Triad calculated its "extended project support" costs based on 105 calendar days. Moreover, Triad's letter to ODFW dated June 7, 1993, asserts a claim for $38,827 for the extended project overhead costs Triad incurred during the period between the contract completion date of November 15, 1992, and May 28, 1993, when it fulfilled the project requirements.
[11]  Triad does not contend that the oral agreement was supported by a separate consideration.


856 F.2d 167
47 Fair Empl.Prac.Cas.  1697,47 Empl. Prac. Dec. P 38,325, 12 Fed.R.Serv.3d 193
Aretha S. BAKER, Plaintiff-Appellant,v.BUCKEYE CELLULOSE CORPORATION, Defendant-Appellee.
No. 88-8045.
United States Court of Appeals,Eleventh Circuit.
Sept. 30, 1988.

James Finkelstein, Albany, Ga., for plaintiff-appellant.
John G. Skinner, Smith, Currie & Hancock, Atlanta, Ga., for defendant-appellee.
Appeal from the United States District Court for the Middle District of Georgia.
Before VANCE and HATCHETT, Circuit Judges, and NESBITT*, District Judge.
NESBITT, District Judge:
Aretha Baker appeals the district court's order denying her motion for a preliminary injunction on the grounds that the court should have held an evidentiary hearing.  Although Fed.R.Civ.P. 65(a) does not require a hearing on every motion for injunctive relief, we hold that on the facts of this case the court erred in not conducting a hearing.
I.
In July 1985 Aretha Baker filed a charge with the Equal Employment Opportunity Commission (EEOC) alleging that her employer, Buckeye Cellulose Corporation had discriminated against her because she is black.  After the EEOC issued a right-to-sue letter, she filed this civil rights action, claiming violations of the Civil Rights Act of 1866, 42 U.S.C. Sec. 1981, and of Title VII of the Civil Rights Act of 1964, 42 U.S.C. Secs. 2000e to 2000e-17.  Her complaint had been pending for four months in the district court when she filed a motion for a preliminary injunction, seeking to enjoin certain alleged retaliatory actions taken by Buckeye as a result of her filing suit.  The motion was set for a hearing, which was cancelled and never rescheduled.  The district court denied the motion in a brief order, stating, "Plaintiff has failed to establish to any degree of certainty that she has been legitimately harmed or even threatened with harm.  The court finds that this issue is not ripe for pretrial adjudication."
On appeal, Baker argues that the district court erred in denying the motion for preliminary injunction without first having an evidentiary hearing.  Buckeye contends that the trial court did not even have jurisdiction over the motion because it contained allegations that had not been presented to the EEOC and were not a part of the original charge or complaint.  Alternatively, Buckeye contends that Baker failed to establish that she was entitled to injunctive relief, and that the district court did not abuse its discretion in denying the motion without a hearing.
II.
A. Jurisdiction
In its order denying Baker's motion for a preliminary injunction, the district court did not address the issue of subject-matter jurisdiction.  Buckeye argues that the court did not have jurisdiction to consider the motion because she had not asserted the retaliation claim either before the EEOC or in her complaint.  Under Buckeye's theory, Baker would have to file a new charge with the EEOC alleging retaliatory actions, obtain a right-to-sue letter, and either file a new complaint in the district court or amend the complaint in the pending case.
In Gupta v. East Texas State Univ., 654 F.2d 411 (5th Cir. Unit A Aug. 1981), the court held thatit is unnecessary for a plaintiff to exhaust administrative remedies prior to urging a retaliation claim growing out of an earlier charge;  the district court has ancillary jurisdiction to hear such a claim when it grows out of an administrative charge that is properly before the court.
There are strong practical reasons and policy justifications for this conclusion.  It is the nature of retaliation claims that they arise after the filing of the EEOC charge.  Requiring prior resort to the EEOC would mean that two charges would have to be filed in a retaliation case--a double filing that would serve no purpose except to create additional procedural technicalities when a single filing would comply with the intent of Title VII.
Id. at 411.1   In Gupta, the district court had allowed the plaintiff to amend his complaint to add allegations of retaliatory discharge, even though he had not filed charges with the EEOC.  Although Baker did not seek leave to amend the complaint in this case before she filed the motion for injunctive relief, the court's reasoning in Gupta still applies.  It has long been established in this circuit that the scope of a judicial complaint is defined by the scope of the EEOC investigation that "can reasonably be expected to grow out of the charge of discrimination."   Sanchez v. Standard Brands, Inc., 431 F.2d 455, 466 (5th Cir.1970);  see also Turner v. Orr, 804 F.2d 1223, 1226-27 (11th Cir.1986).  Because a claim of retaliation could reasonably be expected to grow out of the original charge of discrimination, the district court had jurisdiction over the motion for injunctive relief.
B. Necessity of a Hearing
As both parties recognize, a district court's order granting or denying a preliminary injunction is reviewable only for abuse of discretion.   See United States v. Jefferson County, 720 F.2d 1511, 1519 (11th Cir.1983).  A district court may grant injunctive relief if the movant shows (1) a substantial likelihood that she will ultimately prevail on the merits;  (2) that she will suffer irreparable injury unless the injunction issues;  (3) that the threatened injury to the movant outweighs whatever damage the proposed injunction may cause the opposing party;  and (4) that if issued, the injunction would not be adverse to the public interest.  Id. (citing Shatel Corp. v. Mao Ta Lumber and Yacht Corp., 697 F.2d 1352, 1354-55 (11th Cir.1983)).
In the instant case, the district court found that Baker had not established any harm, or even any threatened harm.  In this circuit, however, courts are to presume irreparable harm in Title VII cases.   Jefferson County, 720 F.2d at 1520;  Middleton-Keirn v. Stone, 655 F.2d 609, 611 (5th Cir. Unit B 1981).  On the facts of this case, we hold that the district court erred in not conducting an evidentiary hearing to determine whether Buckeye could overcome that presumption, or whether Baker had met the other requirements listed above.
Federal Rule of Civil Procedure 65(a) states, "No preliminary injunction shall be issued without notice to the adverse party."    The United States Supreme Court has noted in passing that "[t]he notice required by Rule 65(a) before a preliminary injunction can issue implies a hearing in which the defendant is given a fair opportunity to oppose the application and to prepare for such opposition."   Granny Goose Foods, Inc. v. Brotherhood of Teamsters, 415 U.S. 423, 432 n. 7, 94 S.Ct. 1113, 1121 n. 7, 39 L.Ed.2d 435 (1974).  The intended purpose of the rule is to give the party opposing the motion for injunctive relief an adequate opportunity to prepare;  however, Baker asserts that the moving party is also entitled to an opportunity to prove up the motion at a hearing.  Rule 65(a) does not expressly require a hearing on every motion for injunctive relief;  however, where there is a presumption of irreparable harm, as in this case, the court should conduct an evidentiary hearing before granting or denying the motion.
The order denying Baker's motion seems to rely solely on her failure to prove irreparable harm.  On remand, the district court should conduct an evidentiary hearing to determine not only whether Buckeye has rebutted the presumption of irreparable harm but also whether Baker has satisfied the other three requirements for the issuance of a preliminary injunction.   See Middleton-Keirn, 655 F.2d at 612.
III.
The district court's decision denying Baker's motion for a preliminary injunction is reversed and remanded for further proceedings.
REVERSED and REMANDED.

*
 Honorable Lenore C. Nesbitt, U.S. District Judge for the Southern District of Florida, sitting by designation

1
 This case is binding precedent under Bonner v. City of Pritchard, 661 F.2d 1206, 1209 (11th Cir.1981)


535 U.S. 1017
INTERNATIONAL ASSOCIATION OF BRIDGE, STRUCTURAL, AND ORNAMENTAL IRON WORKERS, LOCAL UNION NUMBER 55, ET AL.v.WALCHER & FOX, INC.; andWALCHER & FOX, INC.v.INTERNATIONAL ASSOCIATION OF BRIDGE, STRUCTURAL, AND ORNAMENTAL IRON WORKERS, LOCAL UNION NUMBER 55, ET AL.
No. 01-1146.
No. 01-1337.
Supreme Court of the United States.
April 22, 2002.

1
C. A. 6th Cir. Certiorari denied. Reported below: 270 F. 3d 1018.


26 Ariz. App. 304 (1976)
547 P.2d 1104
SUN CITY WATER COMPANY, an Arizona Corporation, Appellant,
v.
The ARIZONA CORPORATION COMMISSION, Appellee.
No. 1 CA-CIV 2934.
Court of Appeals of Arizona, Division 1, Department B.
April 6, 1976.
Rehearing Denied May 19, 1976.
*305 Evans, Kitchel & Jenckes, P.C. by Earl H. Carroll, Phoenix, for appellant.
Robertson, Molloy, Fickett & Jones, P.C. by Charles D. Wahl, Michael J. Meehan, Tucson, for appellee.
OPINION
JACOBSON, Presiding Judge.
This appeal calls into question the manner in which the Arizona Corporation Commission may set a "fair rate of return" *306 on the fair base value of a public service corporation's assets.
The appellant, Sun City Water Co. (Company) appeals from a judgment of the Superior Court of Maricopa County affirming a decision of appellee, Arizona Corporation Commission (Commission) setting the fair rate of return on Sun City's fair base value at 6.72%. The trial court, however, remanded the matter back to the Commission for further hearings on the issue of whether the rate schedule adopted by the Commission would yield a full 6.72% return. Only Sun City has appealed.
The Company is a wholly-owned subsidiary of Citizen's Utilities Company, supplying water to residents of the Sun City area of Maricopa County. On October 13, 1972, the Company filed an application with the Commission, requesting that it determine the fair value of the Company's utility properties, that it fix a just and reasonable rate of return thereon and that it approve rate schedules which would provide the rate of return that was determined. At this time the Company did not propose rate schedules (actual charges for water supplied to customers) as it was unaware of what revenue requirements the Commission would determine were necessary.
The hearings on this application were concluded on May 10, 1973, but the Commission did not issue its rate order until October 23, 1973, approximately a year after the initial application was made. The decision of the Commission established a fair value rate base, determined that 6.72% was a fair return on that base and authorized the Company to charge certain specified water rates, which in the Commission's opinion would yield a 6.72% rate of return. The actual rate schedule adopted was apparently prepared and furnished by the Commission's own staff, without consultation with the Company.
The Company filed an application for rehearing, contending that the 6.72% rate of return was unreasonable,[1] and that in any event the rate schedules adopted by the Commission would not yield this 6.72% return. Further, the Company requested that it be permitted to establish rates pending court review, subject to refund, which would enable it to earn the minimum rate of return testified to by an expert of 7.7%. The Company's application for rehearing was denied and suit followed in superior court.
The hearing before the Commission established that as of July 31, 1972, (the end of the test year for the rate proceeding) substantially all of the Company's 10,150 customers were located in Sun City, a retirement community developed by Del E. Webb Corporation. The water distribution system (mains and services) are installed by Del E. Webb Corporation as contractor. The initial cost of this system is paid for by Del E. Webb Corporation, but the Company repays Del E. Webb Corporation in full for these facilities as customers are attached. This arrangement had the prior approval of the Commission. The Company itself pays for all wells, pumping plants, sewage facilities, buildings, equipment and related facilities. The Company's facilities as such are relatively new.
The evidence before the Commission and subsequently before the trial court on the issue of fair rate of return can be summarized as follows: (1) Dr. Walter A. Morton, an economist and rate of return expert called by the Company, testified that in his opinion a fair rate of return would be 9.46%; (2) Jack O. Sanders, the Company's rate manager, testified that in his opinion a fair rate of return would be 9.75%; and (3) Dr. John K. Langum, also a rate of return expert who testified for the Commission, was of the opinion that a "minimum" rate of return for the Company was "no less than 7.7%."
In essence, the Commission adopted the opinion of its own witness, Dr. Langum, but concluded: (1) Dr. Langum "did not *307 give enough recognition to the results of earnings of the eleven water utilities reported by" him;[2] (2) that the Company's properties were new and thus would have relatively low management and maintenance expense: (3) that because Sun City was one of the fastest growing areas in Arizona there are relatively few unused service connections, and (4) that the Company does not have to pay for its system until it becomes revenue producing and thus the risk is minimal to the owner compared to other utilities. Based upon these factors, the Commission set the rate of return at 6.72%.
At the time of trial before the superior court, Dr. Langum, while still maintaining his original opinion as to a rate of return of 7.7%,[3] was allowed to testify, over objection, that the methods used by the Commission in arriving at its conclusion were reasonable. At this time, the Company also produced evidence that the schedule of rates established by the Commission would in actuality yield a rate of return of only 6.07% instead of the 6.72% set by the Commission.
The issues presented on appeal are:
(1) What is the standard to be applied in judicial review of the Commission's decision?
(2) If the standard of review is the "substantial evidence test", is there substantial evidence which would justify the Commission's conclusion that 6.72% is a fair rate of return?
(3) Did the trial court err in finding that the schedule of rates established by the Commission would yield a 6.72% return?
(4) Was the trial court in error in the manner in which it remanded the matter back to the Commission?
We are first faced with the issue of the scope of judicial review of the decision of the Commission setting a fair rate of return. While both parties agree that the trial before the superior court is de novo, the Company has the burden of showing, pursuant to A.R.S. § 40-254(E), by "clear and satisfactory evidence", that the Commission's decision was unreasonable or unlawful, they differ as to the standard to be applied by the court in making this determination. The Commission, on the one hand, contends that it does not have to demonstrate either the evidence or the method it utilized in reaching its decision, with the limitation that the rate of return may not be confiscatory, but rather if a judicial review shows that the total effect of the rate of return is neither unjust nor unreasonable, judicial inquiry is at an end and the Commission must be affirmed. In support of this proposition, the Commission cites Federal Power Commission v. Hope Natural Gas Co., 320 U.S. 591, 64 S.Ct. 281, 88 L.Ed. 333 (1944).
The Company, on the other hand, points out that the Arizona Supreme Court has rejected the reasoning of the Hope case in rate base cases in Simms v. Round Valley Light & Power Co., 80 Ariz. 145, 294 P.2d 378 (1956). Because of this rejection of the "end result" reasoning of Hope in rate base cases, the Company urges that it should likewise be rejected in rate of return cases. The Company instead urges that the test for review of a rate of return decision of the Commission is that the decision must be supported by substantial evidence which is capable of being articulated to the reviewing court. Stated conversely, if there is no substantial evidence to support the Commission's decision, the Commission's action must be set aside and the matter remanded for further proceedings.[4]
*308 It is clear that the Simms case rejected the reasoning of Hope based on Article 15, § 14 of the Arizona Constitution,[5] requiring that the Commission, in rate base cases, determine the fair value of the utility's property, stating:
"It is clear, therefore, that under our constitution as interpreted by this court, the commission is required to find the fair value of the company's property and use such finding as a rate base for the purpose of calculating what are just and reasonable rates. The Hope case cannot be used by the commission. To do so would violate our constitution. The statute under consideration in that case prescribed no formula for establishing a rate base. While our constitution does not establish a formula for arriving at fair value, it does require such value to be found and used as the base in fixing rates. The reasonableness and justness of the rate must be related to this finding of fair value. (emphasis added) 80 Ariz. at 151, 294 P.2d at 382.
The Commission argues that since the rejection of the rationale of the Hope decision was based upon constitutional considerations, and since there are no constitutional provisions dealing with rate of return as compared to rate base, Simms is not authority for rejecting Hope in rate of return determinations. We agree that the rate of return allowable to a public service corporation is not specifically mentioned in the constitution, but it is apparent that the sole constitutionally mandated purpose in determining the fair value of a utility's property is to enable the Commission to set a fair rate of return  the finding of fair base value having no purpose in and of itself. It is thus somewhat incongruous to say that the Commission cannot use an "end justifies the means" approach to determine the basis of the final determination, but can use that same approach in reaching the final determination itself.
As was stated in Simms, although admittedly dicta;
"The legislative duty and power to fix just and reasonable rates having been by the constitution delegated exclusively to the corporation commission's the courts cannot disturb the commission's ultimate conclusion or findings of facts in arriving at such conclusion when the same is supported by substantial evidence, is not arbitrary or is not otherwise unlawful." (emphasis added) 80 Ariz. at 154, 294 P.2d at 384.
Also see, Florida Rate Conf. v. Florida Railroad & P.U. Com'n, 108 So.2d 601 (Fla. 1959).
Even those cases cited by the Commission in support of the Hope rule have had some difficulty in applying the rule as is evidenced by this passage from State Corp. Com'n v. Federal Power Com'n, 206 F.2d 690 (8th Cir.1953):
"However, the Congress has provided for judicial review of the orders of the Federal Power Commission in such cases. Obviously there must be some review. And as Mr. Justice Jackson stated in Federal Power Commission v. Hope Natural Gas Company, supra, 320 U.S. at page 645, 64 S.Ct. at page 308, `If we are to hold that a given rate is reasonable just because the Commission has said it was reasonable, review becomes a costly, time-consuming pageant of no practical value to anyone.'" 206 F.2d at 722.
We therefore hold that the judicial scope of review of a decision of the Corporation Commission setting a fair rate of return for a public service corporation is to determine whether the Commission's order is supported by substantial evidence, and thus not arbitrary. See, Ariz. Corp. Comm. v. Superior Court, 107 Ariz. 24, 480 P.2d 988 (1971).
*309 In this regard, we specifically reject the rationale of the Hope decision, insofar as that case intimates that the Commission is allowed to reach its determination without fear of judicial scrutiny, as long as the end result is not unjust or unreasonable.
We turn then to a determination of whether the rate of return set by the Commission is supported by substantial evidence. It is first important to define what is "rate of return" and what is a "fair and reasonable" rate of return. "Rate of return" is the income earned by a utility after operating expenses, but before deduction of interest charges divided by the rate base. Thus, rate of return includes the interest which must be paid on short and long term debt and dividends on stock. New England Tel. & Tel. Co. v. Dept. of Pub. Util., 331 Mass. 604, 121 N.E.2d 896 (1954). Simply put, rate of return is the net profit allowed the utility.
The U.S. Supreme Court has defined a fair rate of return in Blue Field Water Works & Improvement Co. v. Public Service Commission of West Virginia, 262 U.S. 679, 43 S.Ct. 675, 67 L.Ed. 1176 (1923):
"What annual rate will constitute just compensation [fair rate of return] depends upon many circumstances, and must be determined by the exercise of a fair and enlightened judgment, having regard to all relevant facts. A public utility is entitled to such rates as will permit it to earn a return on the value of the property which it employs for the convenience of the public equal to that generally being made at the same time in the same general part of the country on investments in other business undertakings which are attended by corresponding risks and uncertainties; but it has no constitutional right to profits such as are realized or anticipated in highly profitable enterprises or speculative ventures. The return should be reasonably sufficient to assure confidence in the financial soundness of the utility and should be adequate, under efficient and economical management, to maintain and support its credit and enable it to raise the money necessary for the proper discharge of its public duties." 262 U.S. at 692-93, 43 S.Ct. at 679.
It is conceded by both the Company and the Commission that the fair rate of return concept embodied in the Blue Field decision requires the determination by the Commission of the "capital costs" of the business.
"Capital costs" as used in rate of return cases refers to the percentage figure it would cost the utility to obtain debt and equity capital. Riverton Consolidated Water Co. v. Pennsylvania Public Utility Commission, 186 Pa.Super. 1, 140 A.2d 114 (1958). Debt cost as a part of a capital cost study is normally not a matter of dispute as it is provable as a historical fact. In this case, all the experts agree that the cost of the company's long-term debt was 6.00% and the short-term debt was 6.58%.
The cost of equity capital is not capable of such mathematical precision and in fact is a judgment call, enlightened by consideration of all the relevant factors. However, for the purposes of this preliminary discussion, cost of equity capital is normally determined by two methods  the "investor method", that is, an analysis of how investors form reasonable expectations of the earning-dividend and growth expectation of utility stocks or the "opportunity cost comparative earnings method", that is, what capital would earn in other enterprises of corresponding risks and hazards.
It is generally conceded by the parties in this case that the "opportunity cost-comparative earnings method" is the more reliable test for determining cost of equity capital and that the "investor's method" is primarily used as a check and guide to other measurements.
This then brings us to the crux of the problem before the court. While the Commission in its written decision states that it "must appraise the equity earning of other utilities, and non-regulated companies, and use this appraisal in setting the allowed *310 rate of return on the equity component in the cost of capital", its decision itself belies this comprehensive appraisal. The Commission rejected Dr. Morton's testimony primarily because he used Moody's Index of 125 Industrials in forming his opinion as to a proper rate of return. The Commission likewise rejected Mr. Sander's testimony because his opinion as to rate of return was higher than the seven water companies used in his report. Finally, Dr. Langum's opinion was modified because he did not give enough recognition to the earnings of the eleven water utilities reported by him. We therefore agree with the Company that the Commission's determination of the rate of return in this case was based solely upon a comparison of the rate of return on regulated water companies.
The Company contends that while it is proper to consider earnings of regulated utilities, to base a decision solely upon such a consideration is improper for three reasons: (1) There is a circularity of analysis if only earnings from regulated water companies are used, (2) the water company industry generally is in a distressed financial situation and therefore earnings from that industry are not reflective of a fair rate of return and (3) limiting consideration to water companies alone does not give adequate weight to the realities of the comparative money market and attraction of investments. In our opinion, the Company's contentions are well founded.
We agree with the statement in Garfield & Lovejoy, Public Utility Economics, at pg. 120, concerning the impropriety of looking only to earnings of other regulated utilities in reaching rate of return determination:
"First, there is a degree of circularity of analysis in looking to the earnings of other regulative utilities as an indication of what a fair return to a particular regulated utility might be. Second, the earnings of companies in the test group may have lagged adjustments to changed conditions, so that they either understate or overstate typical average earnings to such companies. Third, there is a question of whether utilities in the test group are regulated by the same methods as the utility in question."
The problem inherent in looking at utility A to fix utility B's rate of return and then looking at utility B to fix utility A's rate of return is "rather like observing an endless series of duplicate images in multiple mirrors, [and] would be hopelessly circular." Re Union Electric Company, 47 F.P.C. 144 (1972).
This problem is, in our opinion, compounded when only a specialized segment of the regulated utility industry is used as a comparison basis. In this case, the Commission, in our opinion, not only looked solely to regulated utilities in reaching a rate of return for the company, it limited its review to only a particular segment of that industry  water companies. While admittedly water companies are the most comparable utility to the Company, being itself a water company, the image reflected by that comparison is only that of other water companies and not what is a "fair rate of return". This is especially true, when evidence was presented that this industry was generally sick financially and that at least two of the companies used for comparison purposes had either merged with other companies or subsequently obtained rate of return increases. Companies which are used for comparison purposes must be successful and not in a financially sick condition. Nichols, Ruling Principles of Utility Regulation, Rate of Return (1955), at 310.
Finally, in order for the Commission to intelligently exercise its judgment in setting a rate of return, consideration must be given to the competitive money market for investments. As has been aptly pointed out by Professor Priest in his treatise, Principles of Public Utility Regulation, Volume I, a potential investor is under no restraint where he places his money, be that in corporate stocks, government bonds, debentures, or the capital gains *311 promised by high growth investments. Under such circumstances unless the investor is offered utility opportunities substantially comparable to other types of investments, the utility company will go begging for funds. We therefore hold that the Commission should give consideration to yields returned by these other types of investments when setting a rate of return for a utility. We do not mean to intimate that the utility is entitled to a rate of return comparable with a high risk, speculative stock. Rather, we are simply saying that the Commission in setting rates of return should properly consider the competitive investment market generally in order to avoid the possibility of placing the utility in an unfair investment situation.
Based upon the foregoing, we hold that the Commission improperly limited its decision in comparing only regulated water companies and because of this limitation, the Commission's decision is not based upon substantial evidence and must be set aside.
In setting aside this rate of return decision, we reiterate that the determination of a rate of return which includes a cost of equity factor, is not a precise science, and that reasonable men may differ as to its fair result. We do hold, however, that in reaching that result the Commission must consider all relevant factors and give the weight to them individually that in the opinion of the Commission they deserve. We are also cognizant that the Commission should not be bound solely by the opinions of experts which appear before it, be those company experts or staff experts. However, the right to reject opinions does not operate to create positive evidence or obviate the requirement that there be substantial evidence to support its conclusion. City of Newport v. Newport Electric Division of Citizens Utilities Co., 116 Vt. 103, 70 A.2d 590 (1950).
Since this matter must be remanded to the Commission for further determinations, we will pass on the Company's contention that the Commission improperly considered the age of the Company's facility, the contractual relationship on extensions to its system with Del E. Webb Corporation, and the fact that the Company services a fast growing area. In our opinion, the Commission may properly consider these factors insofar as they relate to the question of risk to the potential investor. See, Bluefield, supra; Wabash Valley Electric Co. v. Young, 287 U.S. 488, 53 S.Ct. 234, 77 L.Ed. 447 (1933). We also note in passing that while we find no statutory procedures for the Company being allowed to participate in the fixing of rate schedules after a fair rate of return has been determined, such participation is, in our opinion, highly desirable to avoid future litigation and to enable the Commission to have placed before it all the competent data relative to that determination.
As previously indicated, the question of the Company's fair rate of return has been pending before the Commission and the courts since October, 1972. Because of this passage of time, we are of the opinion that under the authority of Ariz. Corp. Com'n.v. Mountain States Tel. & Tel. Co., 71 Ariz. 404, 228 P.2d 749 (1951), Sun City Water Company should be entitled to fix a just and reasonable schedule of interim rates, pending action by the Commission. Therefore, the issuance of our mandate in this matter shall be authority to the Company to fix a just and reasonable schedule of rates for the use of its water pending the action of the Commission in establishing a fair rate of return and a schedule of rates which will provide the rate of return established. However, to adequately protect the water customers served by the Company from an unjust and unreasonable rate being fixed by the Company, the authority of the Company to fix such rates shall be conditioned upon the Company posting a bond with the Commission in an amount to be determined by the trial court. The conditions of the bond shall be that should the rates fixed by the Company exceed the rates finally established by the Commission to be just and *312 reasonable, then the Company shall refund to its customers the excess which it collected over and above the amount the Company would have collected had the rates finally determined by the Commission to be just and reasonable been in effect. If the rates finally determined by the Commission to be just and reasonable are equal to or more than the interim rates fixed by the Company then the bond shall be discharged.
Since we reverse the decision of the superior court and remand this matter to the Commission for further proceedings, for a proper determination of rate of return and rate schedules, we do not reach the other issues raised by the Company on appeal.
The judgment of the superior court is reversed and the matter remanded to the trial court for a determination of the amount of bond to be posted by the Company and upon that determination being made, the trial court is directed to remand the matter back to the Commission for further proceedings consistent with this opinion.
EUBANK and FROEB, JJ., concur.
NOTES
[1]  The Company did not either before the Commission or before the trial court object to the fair value rate base established by the Commission.
[2]  The above quotation is from the Commission's decision.
[3]  The difference between Dr. Langum's opinion of 7.7% return and the 6.72% fixed by the Commission results in an estimated loss to the Company of approximately $130,000.00 per year.
[4]  Both parties agree that the court itself has no authority to set the rate of return and this function must be performed by the Commission.
[5]  Art. 15, § 14, Arizona Constitution, provides in part: "The Corporation Commission shall, to aid it in the proper discharge of its duties, ascertain the fair value of the property within the State of every public service corporation doing business therein; ..."