delivered the opinion of the Court.
This appeal focuses upon the power of a county administrator to execute a contract that binds the county for which he works.
In January 1977, Richard E. Bain, then the York County Administrator, signed, purportedly on behalf of York County, a contract titled “County of York, Subdivision Agreement.” The contract was countersigned on behalf of King’s Villa, the other party thereto, by its president. In addition, the contract was signed by *449the York County Attorney on a signature line marked: “Approved as to form.”
The contract contains many recitals and conditions, but crucial among these for the purpose of this appeal is the following language contained in paragraph 4:
In the event County does not undertake to construct a permanent pump station or does not complete the construction of the permanent pump station on or before January 1, 1979, then and in that event, Owner agrees to build a permanent pump station in accordance with the plans and specifications and in the location as shown which the County now has on file; provided however, that any costs of construction of the permanent pump station by Owner in excess of $50,000 shall be reimbursed immediately up to the amount of tap fees upon payment of such tap fees chargeable on Sections 1, 2, 3 of King’s Villa Subdivision. Such tap fees shall be $700.00 for each structure to be connected to the sewer.
(Emphasis added.) The last sentence lies at the bottom of this dispute. The County argues that by including the italicized language in the contract, the County Administrator attempted to lock the connection fee in place and by that attempt intruded into an area exclusively reserved for the County Board of Supervisors.
At the time the contract was signed, the connection fee, as set forth in the County’s wastewater ordinance, was $700.00 per structure the same figure as recited in the contract. However, in June 1977, five months after the date of the contract, the York County Board of Supervisors amended the wastewater ordinance and increased the connection fee to $1,250.00. The County attempted to collect the new fee from King’s Villa. But King’s Villa refused to pay more than $700.00 per connection and filed suit to enjoin the County from collecting the increased fee and to force it to abide by the January 1977 contract.
The trial court agreed with King’s Villa, enjoined the County from charging the increased fee, ordered the County to charge the $700.00 fee contained in the January 1977 contract, and directed the County to return to King’s Villa any amounts in excess of $700.00 per connection which had already been collected.
The County appealed, claiming that its Administrator had no power permanently to set the connection fee at $700.00 per con*450nection and that to that extent the italicized portion of the January 1977 contract, quoted above, is void and of no effect. We agree. Therefore, we will reverse the decision of the trial court and enter final judgment for the County.
The power to fix or change the connection fee rests exclusively in the York County Board of Supervisors. This is true whether the Board of Supervisors acts in its capacity as the Board of Supervisors, Code § 15.1-320(7), or in its capacity as the governing body of a sanitary district, Code §§ 21-118(5) and 21-118.4(e). In Armstrong v. Henrico County, 212 Va. 66, 77, 182 S.E.2d 35, 43 (1971), we held that setting rates and fees for sewer or water services is a nondelegable legislative function. Thus, the only way the connection fee could have been locked in place indefinitely was for the County Board of Supervisors to authorize such expressly. It could have done this by adopting a resolution to that effect, by ratifying the portion of the contract related to the connection fee, or by other express means.
Here, the County Administrator tried to do more than he was empowered to do. He never had the authority permanently to fix rates and fees. Neither the York County Board of Supervisors nor the governing body of the sanitary district could have authorized the County Administrator to freeze rates and fees indefinitely even if they had wanted to.
King’s Villa is in the unfortunate position of having dealt in good faith with a public servant who exceeded the bounds of his authority. This is not an uncommon problem nor is it one which engenders goodwill on the part of citizens for governmental officials with whom they must deal. For it is true that where, as here, a contract was prepared by the County Administrator and approved as to form by the County Attorney, a citizen might easily conclude, without further inquiry or investigation, that every part of the contract was legal and binding and could be relied upon. However, we have cautioned in several cases that those who deal with public officials must, at their peril, take cognizance of their power and its limits. Deal v. Commonwealth, 224 Va. 618, 623, 299 S.E.2d 346, 349 (1983); S. H. Apts. v. Elizabeth City Co., 185 Va. 67, 78-79, 37 S.E.2d 841, 846 (1946).
The rule of caution repeated above is the outgrowth of competing and conflicting demands. On one hand, the law favors contracts and attempts to uphold and enforce them wherever possible. On the other hand, our system of government is designed to re*451strain public officials from having unfettered, unchecked control over governmental affairs. This means that there are limits on the powers of the various levels of government and curbs on the powers entrusted to agents of government. Were we to rule in favor of King’s Villa we would rend the fabric of government because we would be permitting the judgment of one official to supplant the collective wisdom of the elected governing body whom the people have chosen to wield the power here in dispute. Instead of having rule by the Board of Supervisors we would be allowing rule by one man, who in the final analysis is but an employee of the Board. Such a result is unacceptable under our form of government.
The arguments advanced by King’s Villa in support of the contract are not persuasive, and are easily disposed of. King’s Villa fails to point to any express authority on the part of the County Administrator to set in place for all time a connection fee of $700.00. Instead, it argues that on the bases of the York County Subdivision Ordinance and Code § 15.1-117, Bain had the implied authority to so bind the County.
It is plain that neither the ordinance nor the Code gives rise to the implication urged by King’s Villa. The Subdivision Ordinance states as follows with regard to the role of the County Administrator:
The County Administrator for the County of York or his duly authorized agent is hereby appointed Subdivision Agent and shall on behalf of the Board, administer and enforce the provisions of this ordinance.
There is nothing in the ordinance concerning the permanent setting of connection fees.
Code § 15.1-117(14) is likewise of no avail. It merely provides the County Administrator is “[t]o perform such other duties as may be imposed upon him by the governing body.” The short answer is the Board of Supervisors could not and did not give Bain the authority permanently to fix the connection fee.
In oral argument, King’s Villa’s counsel contended that Code § 15.1-466(J) provides a basis for implying that Bain had the power to bind the County to a fee of $700.00. As far as we can discern, however, counsel misspoke. Code § 15.1-466(J) has no relation whatever to setting the connection fee. It merely provides that a subdivision ordinance shall include reasonable regula*452tions for payments by subdividers and developers of their pro rata share of the cost of providing reasonable and necessary sewerage and drainage facilities. This gave Bain no power, expressly or by implication, permanently to fix the sewer connection fee in a contract.
King’s Villa also argues that the County is estopped to deny the contract. Yet the doctrine of estoppel has no application here. We explained in Deal v. Commonwealth, supra, that where a contract executed by an agent of the government is ultra vires it is void ab initio and of no legal effect; thus no performance by either party thereto can give the unlawful contract validity or serve as the basis of any right of action upon it and the doctrine of estoppel has no application. 224 Va. at 623, 299 S.E.2d at 348-349. Accord School Board v. Burley, 225 Va. 376, 379, 302 S.E.2d 53, 55 (1983). See Richmond R. Co. v. Richmond, etc., 145 Va. 266, 299, 133 S.E. 888, 898 (1926).
Reversed and final judgment.