Holt, J.,
delivered the opinion of the court.
In December, 1932, the city of Norfolk, by proper procedure in the Circuit Court of Nansemond county, made application for the correction of, and exoneration from the payment of, certain alleged erroneous assessments of taxes and levies made by the authorities of that county upon that portion of the water works of the city which lay within its limits. That court was of opinion that the city was not entitled to the relief prayed for and from its decision comes this appeal.
The valuation placed upon this property by the county authorities is not challenged; indeed, there are no important issues of fact presented in the record. Those presented are [612]*612in the main constitutional and necessitate a re-examination of those provisions which we have often had occasion to consider and which appear in section 183 of the Constitution of Virginia.
Our present Constitution went into effect in 1902. Later there was a general revision of its provisions—see joint resolution of the legislature adopted February 27, 1928 (Session Acts 1928, chapter 46). Exemptions first given from taxation and pertinent changes in those exemptions can best be shown by comparing related sub-sections in section 183 of the Constitution of 1902 and of the Constitution as it stands today.
Constitution of 1902.
“Section 183. Property exempt from taxation.—Except as otherwise provided in this Constitution, the following property and no other, shall be exempt from taxation, State and local; but the General Assembly may hereafter tax any of the property hereby exempted save that mentioned in sub-section (a):
“(a) Property directly or indirectly owned by the State, however held, and property lawfully owned and held by counties, cities, towns, or school districts, used wholly and exclusively for county, city, town or public school purposes, * * #.
“(g) * * * and whenever any building or land, or part thereof, mentioned in this section, and not belonging to the State, shall be leased or shall be a source of revenue [613]*613or profit, all of such buildings and land shall be liable to taxation as other land and buildings in the same county, city or town; * *
[612]*612
Constitution as Amended in 1928.
“Section 183. Property exempt from taxation.—Unless otherwise provided in this Constitution, the following property and no other shall be exempt from taxation, State and local, including inheritance taxes:
“(a) Property owned directly or indirectly by the United States, the Commonwealth or any political subdivision thereof, * #
“Whenever any building or land, or part thereof, mentioned in this section, and not belonging to the State, shall be leased or shall otherwise be [613]*613a source of revenue or profit all of such buildings and land shall be liable to taxation as other land and buildings in the same county, city or town. But the General Assembly may provide for the partial taxation of property not exclusively used for the purposes herein named.”
By said sub-section (a) in the Constitution of 1902, properties owned by cities, to be exempt from taxation, must be used wholly and exclusively for municipal purposes. No such provision appears in the revision of 1928, and so we think it plain that this omission did not narrow exemptions originally given. Indeed, the revisors of 1928 tell us that no material changes were intended.
Sub-section (g), so far as it deals with exemptions, is not changed at all, save in this: The legislature might limit the right to tax—that is to say, it might provide for partial taxation and for apportionment. This power granted was not immediately exercised and was not exercised until March 25, 1930 (Acts of Assembly 1930, ch. 397, p. 833; Tax Code, section 435a).
This Code provision could neither enlarge nor contract constitutional limitations and could only deal with the proper assessment and distribution of taxes lawfully levied. It gave no new right to levy and could not come into operation until after a lawful levy had been made.
Norfolk’s water works system was established in 1872 and has since been constantly enlarged to meet increasing demands. Lake Prince was added in 1922. An interesting account of its continuous development appears in the record. Some small sources of supply have been abandoned because their use was uneconomical and much of the work once done has become obsolete. There were two other water companies in this vicinity, the Norfolk County Water Company and the Portsmouth, Berkley & Suffolk Water Company. They appear to [614]*614have been failing ventures and were taken over by the city, and it was from the latter company that Lake Prince was purchased.
In 1919 city demands for the use of its own inhabitants had grown to such an extent that a water famine was imminent and the necessities of the city were urgent. It was this which led to the purchase and development of Lake Prince in Nansemond county. That source of supply became available in 1922 and from it now comes about fifty per cent of the city’s water.
It, the county now contends, should pay county taxes, although no effort to levy such a tax was made for ten years. Acquiescence in this interpretation of the county’s rights by those charged with the administration of its affairs, while not conclusive, is valuable. Superior Steel Corp. v. Commonwealth, 147 Va. 202, 136 S. E. 666; Houghton v. Payne, 194 U. S. 88, 24 S. Ct. 590, 48 L. Ed. 888.
This general rule also should be remembered: Exemption from the burden of taxation extended to individuals or private corporations must be strictly construed. But this rule does not apply to property like that mentioned in section 183. The policy of the State has always been to exempt it. Property held by the State or by a political subdivision of it and for a public purpose has never been dealt with as if it were a private venture. To do so would be in substance a tax by the State upon itself.
In Commonwealth v. Lynchburg Y. M. C. A., 115 Va. 745, 80 S. E. 589, 590, 50 L. R. A. (N. S.) 1197, Judge Buchanan said:
“The exemptions from taxation provided for by section 183 of the Constitution are in accord with the policy of the State from an early day. The Constitutional Convention, in taking away the power of exemption from the legislature, did not intend to change the old policy of the State on the subject, but placed limitations upon the use of property exempted so as to prevent the perversion or abuse of the liberality of the State.
“It is insisted by the Commonwealth that the provision of section 183 of the Constitution must receive a strict construe[615]*615tion. The general rule is that provisions exempting property of individuals or private corporations from taxation must be strictly construed, taxation of such property being the rule and exemption from taxation the exception. One of the reasons for this is that all such persons should bear their fair share of the burdens of taxation, and that lessening the burden of one increases the burdens of others. But as the policy of the State has always been to exempt property of the character mentioned and described in section 183 of the Constitution, it should not be construed with the same degree of strictness that applies to provisions making exemptions contrary to the policy of the State, since as to such property exemption is the rule and taxation the exception.”
We look to the Constitution of 1902 in determining the validity of the assessment made in 1928. Succeeding assessments are governed by the Constitution as it stood amended in 1928. Assessment for 1929 was made under it; those for all succeeding years were likewise made; but those made after 1929 are also affected by and subject to the limitations imposed by the apportionment statute of 1930, which of course is not retroactive.
Is the assessment made in 1928 valid? We have seen that under sub-section (a) of section 183 property to be exempt must be owned and held by the city, and it must be “used wholly and exclusively” for city purposes. Under sub-section (g) it may also be taxed if it “be leased or shall otherwise be a source of revenue or profit” to the city.
There is no question as to ownership, but it is contended that this supply of water is not used wholly and exclusively for city purposes. That qualifying provision turns upon the uses to which this property has been put. While use and not profit is the test, yet the absence of a purpose to profit at times tends to clarify the nature of the use, and an unauthorized use may be too small to notice.
In Commonwealth v. City of Richmond, 116 Va. 69, 81 S. E. 69, 72, L. R. A. 1915A, 1118, it appears that the Commonwealth in 1912 undertook to levy a tax upon certain properties and utilities owned by the city, including its water works. The city’s total receipts from that source for 1911 [616]*616were $254,122.48, and in that year there was received from water consumers outside the city’s limits $6,455.28. With these figures before it the Commonwealth’s claim received short shrift. The court said that these outside receipts “would seem to us de minimis and as not requiring further consideration.” It did, however, go on to say:
“The principle sustained by the ‘weight of authority,’ as well as elementary writers, is that all property lawfully owned and held by cities and towns for governmental purposes, though a source of revenue or profit, which was paid into the city treasury and used for municipal purposes by the city, the dominant purpose in the use having direct reference to the purposes for which the property is authorized by law to be owned and held, and tends immediately and directly to promote those purposes, is exempt from State taxation.”
And in support of that conclusion is cited with approval this statement from Professor Pond’s work on Public Utility:
“Nor should the fact that revenue may be derived from the operation of such plants by the city change the principle of their exemption from taxation, for in no sense can that fact alter the nature of the use to which such property is put, nor the purpose accomplished by such use. And this is the test of its being a proper subject of support by taxation and of exemption from taxation. That revenue may be realized from such plants, tending to make them self-supporting, is no reason for subjecting them to the payment of taxation for their own support and that of the government to which they belong. This incidental matter of revenue does not change the nature of the use or purpose of such property from a public one and for municipal purposes generally, to one that is wholly private and that is conducted for the sole purpose of pecuniary profit rather than for the general welfare, and so liable to taxation.”
All of this the court must have thought applied to the Commonwealth’s claim there asserted. The fact that Richmond furnished water to Barton Heights and to near-by industrial plants did not change the character of the use.
[617]*617In Board of Supervisors v. Norfolk, 153 Va. 768, 151 S. E. 143, 146, this court said:
“So long as the dominant purposes for which the lands were purchased are maintained, incidental uses which serve in some small degree to lessen the city’s burdens although foreign to, but not in derogation thereof, and which do not change the character of the holding, are not sufficient to bring them within the exception noted in the Constitution, and to make them a subject for taxation.”
Although it is true that we held the receipts there to be de minimis.
In Commonwealth v. Trustees of Hampton Normal & Agricultural Institute, 106 Va. 614, 56 S. E. 594, an attempt was made to tax, among other properties of the Hampton Normal & Agricultural Institute, what was known in the record as the “Hemenway” farm. On it, for the instruction of its pupils, the Institute established a model dairy farm and from it there was received something like $9500 a year for products sold to outsiders, but it was held that this large income was but an incident of an undertaking whose dominant purpose was the instruction of its pupils. It was the use to which this farm was put, independent of profits derived from its operation, not here de minimis, which warranted an exemption.
Recently we have had occasion to consider the principles involved. In Light v. City of Danville, ante, page 181, 190 S. E. 276, the right of eminent domain was upheld. Danville is undertaking to establish a hydro-electric plant in a distant county. Already that city is supplying electricity to its urban community, part of which is outside of its corporate limits, and it was conceded that this custom would be continued when the new plant had been established. The court was of opinion that tins extra-urban use was but an incident of a major and dominant purpose. Plainly Danville could not condemn land in furtherance of a venture whose purpose was to supply outside consumers. The right to condemn was upheld because the dominant design was a public use. Compare Shoemaker v. U. S., 147 U. S. 282, 297, 13 S. Ct. 361, 37 L. Ed. 170.
[618]*618Of course there must be reason in all things. Ashland, to supply itself with water, could not dam James river and out of its surplus serve all the needs of Richmond.
If built-up settlements contiguous to Norfolk were not furnished water for domestic uses, for sewerage purposes and for fire protection, they would soon become a menace both to its safety and to its health, and so such service is but incidental to Norfolk’s major purpose, which was never one for profit, major or minor.
We have seen that Lake Prince was acquired because of an urgent present municipal demand. A water famine was at hand and that situation differentiates this case from the Newport News cases, Warwick County v. Newport News, 153 Va. 789, 151 S. E. 417, and Newport News v. Warwick County, 159 Va. 571, 166 S. E. 570, 167 S. E. 583.
The Newport News Light & Water Company and the Old Dominion Land Company were private allied corporations organized for profit and controlled practically the entire sources of water supply in the lower peninsula of Virginia. They supplied the city of Newport News, the city of Hampton, the town of Phoebus, Buckroe Beach, the town of Kecoughton, Hilton Village, Fort Eustis, the settlement at Old Point and intervening suburban communities with water.
Newport News undertook to purchase this system, actuated doubtless by a desire to supply itself and to profit by outside operations. This it did, acting under authority given by its charter, general laws and a special act of the General Assembly approved March 25, 1926 (Acts of Assembly, 1926, ch. 530, p. 880). Under obligations imposed by this act on Newport News are these:
“2. Upon the purchase of said water works plant by the city of Newport News, the said city shall continue to serve all corporations or persons now being supplied with water by said water works system in York county, James City county, Warwick county, Elizabeth City county, the city of Hampton, the town of Phoebus and United States to supply water to Fort Eustis, Navy mine depot, Langley aviation field, Fortress Monroe and the National Soldier’s Home, upon such terms and conditions as may be agreed upon.”
[619]*619This dual consideration, a purpose to profit and the obligation to serve outside interests, runs like a leitmotif through all the Newport News water cases.
Acting upon authority conferred and upon limitations imposed, it sells about one-third of its supply to outside consumers. Warwick County v. Newport News, 153 Va. 789, 151 S. E. 417.
The case of Newport News v. Warwick County, 159 Va. 571, 166 S. E. 570, 582, 167 S. E. 583, is the authority reluctantly relied upon by the Judge below, and so it is important that we know its scope. Speaking through Mr. Justice Chinn, in conclusion, it is said:
“In view of the conclusions expressed, we are of opinion that the judgment of the trial court should be affirmed, in so far as it holds that the lands and buildings thereon, belonging to the city of Newport News as a part of its water works system, situated in Warwick county, were a source of revenue or profit to said city of Newport News during the year 1928, within the meaning of section 183 of the Constitution, as amended, and liable to taxation by Warwick county for the year 1929; * *
These profits he elsewhere states must be substantial.
The situation is further clarified by this observation of the Chief Justice made upon petition to rehear:
“* * # the court deems it only necessary to say that the opinion in question expressly applies the construction therein placed upon the amended section (183) of the Constitution to the facts and circumstances of the case under consideration, and does not undertake to apply such construction to a situation in which a municipality owns and operates a water works system wholly and exclusively for its own municipal purposes. * * *”
Plainly the sale of water by Newport News to outlying communities was not incidental; it was in response to a statutory mandate, and profits for the year in judgment were found by the court to be $77,892.76. Assuming that this finding of fact is accurate, liability to taxation follows as a matter of course.
[620]*620Norfolk’s service to its suburbs was incidental to the purpose for which Lake Prince was acquired and served to protect itself in the manner noted, possibly with the exception of Virginia Beach whose purchases amounted to $10,000, which compared to the magnitude of the city’s operations was inconsequential.
Mr. W. P. Jordan, a certified public accountant testifying for the county, has placed in evidence a statement showing income and expenses for the years in judgment. Spealdng in thousands, the city received from water rents for the year 1927 $827,000, including receipts from outside sources, in amount $53,000, which is something less than 7% of its gross water rate income. Rates to outsiders are higher, the cost of service was high, and so it is probable that only 6% or less of water used was thus consumed. We think this is de minimis, and if it were not, the city should not be taxed, because this use in any aspect of this case was, as we have seen, but incidental. It was not made for profit—there was no profit—and it was not made in response to any statutory mandate.
Has this water works system been a source of revenue or profit as defined in sub-section (g) of section 183 of the Constitution of 1902?
Certainly “revenue” and “profit” are not, as these terms are commonly used, synonyms, and so it may be argued that the city has received revenue from its water system. Certainly it has received more than $800,000 from that source.
These terms, however, we have already construed. In Commonwealth v. City of Richmond, supra, there was a revenue of over $250,000, and yet that revenue did not warrant the imposition of taxes, while Newport News v. Warwick County, supra, proceeds upon the theory that there must be substantial net profits. Not until there have been charged against and deducted from the gross income all proper charges and expenses, and not unless there then remains a substantial net profit, can there be any taxes assessed against a city under said sub-section (g).
Expert accountants have been examined at length, both for the city and for the county. Any detailed discussion of the many items covered would be endless and fruitless.
[621]*621For convenience, we shall deal with thousands only. Mr. Breeden’s estimate of gross receipts for the year 1927 is $842,000. Mr. Jordan puts those receipts at $854,000. From each of them should be deducted a $6,000 item received from the sale of fishing privileges in Lake Prince. This was an incidental income, just as was the sale of milk from a model dairy farm, established for the use and instruction of students at the Hampton Institute, in amount, $9,000. If the Institute should not be charged with that $9,000 in estimating its income, Norfolk should not be charged with this $6,000. Fish from Lake Prince and milk from the Hampton farm are sources of income not contemplated when they were acquired. Deducting this item of $6,000, the receipts of both these experts are, respectively, $836,000 and $848,000.
Mr. Breeden states that the expenses of operation were $853,000. That estimate includes a sinking fund annuity of $161,000, which, for reasons hereafter to be stated, should be stricken out. To it for like reasons should be added a depreciation item of $210,000. Making these changes, the city’s expenses were $902,000.
Mr. Jordan puts operating expenses at $237,000, to which he adds interest on bonded debt, $455,000, making an aggregate of $692,000. If to this be added a depreciation item of $210,000, his estimate of expenses also aggregates $902,000.
Making the changes indicated in Breeden’s estimate, the city lost for the year in judgment $66,000, and according to Jordan’s estimate it lost $54,000.
The county, however, contends that the item of $210,000 should not be allowed. The evidence of the city fixes the amount, but the county claims that a charge of this character should not be admitted at all; that against profit should be charged only current repairs and replacements. It also claims that there should be charged against the city for the city’s use of water, for fire protection, etc., $ 148,000.
If this contention be sound, these results follow: The city’s gross receipts were $848,000. If we add to it said item of $148,000, its receipts were $996,000, while its expenses were but $692,000, from which it would follow that the city’s profits were $304,000.
[622]*622We are, therefore, to determine if the sinking fund annuity of $161,000 should be allowed, if the depreciation item of $210,000 is to be allowed, and if there should be charged against the city said item of $148,000.
A sinking fund is a sum set apart out of current net income to meet a present obligation which has not yet matured, but which will mature at some future stated date. Sinking Fund Cases, 99 U. S. 700, 25 L. Ed. 496; 58 C. J. 738. If the debt and its maturity were not known, there could be no intelligent estimate of the necessary sinking fund annuity. Since it is taken out of current net income, it is a part of that income and must be included in any statement of a corporation’s actual income for any given year. A corporation might be highly prosperous and yet its obligations and their maturity might be such that a proper sinking fund annuity would for a stated time absorb its entire income. We think, for these reasons, that the city is not entitled to the credit claimed for the item of $161,000.
We are to determine what credit or allowance, if any, is to be given the city for depreciation or replacements over and above current repairs. “Depreciation may be defined as the loss in value of some destructible property over and above current repairs.” Cumberland Tel. & Tel. Co. v. City of Louisville (C. C.) 187 F. 637, 653.
“A water plant, with all its additions, begins to depreciate in value from the moment of its use. Before coming to the question of profit at all the company is entitled to earn a sufficient sum annually to provide not only for current repairs but for making good the depreciation and replacing the parts of the property when they come to the end of their life. The company is not bound to see its property gradually waste, without making provision out of earnings for its replacement. It is entitled to see that from earnings the value of the property invested is kept unimpaired, so that at the end of any given term of years the original investment remains as it was at the beginning. It is not only the right of the company to make such a provision, but it is its duty to its bond and stockholders, and, in the case of a public service corporation at least, its [623]*623plain duty to the public.” City of Knoxville v. Knoxville Water Co., 212 U. S. 1, 29 S. Ct. 148, 152, 53 L. Ed. 371.
“The amount of the allowance for depreciation is the sum which should be set aside for the taxable year, in order that, at the end of the useful life of the plant in the business, the aggregate of the sums set aside will (with the salvage value) suffice to provide an amount equal to the original cost.” United States v. Ludey, 274 U. S. 295, 47 S. Ct. 608, 610, 71 L. Ed. 1054.
A public utility rate, which takes no notice of such an allowance, may be confiscatory. Columbus Gas & Fuel Co. v. Public Utilities Commission of Ohio, 292 U. S. 398, 54 S. Ct. 763, 91 A. L. R. 1403, 79 L. Ed. 1327.
Its appearance in the annual balance sheets of all large corporations may be said to be a universal practice. We have approved it in principle as a proper practice. Judge Campbell, in Lehigh Portland Cement Co. v. Commonwealth, 146 Va. 146, 135 S. E. 669, 670, said:
“We have followed with keen interest the able argument of counsel for the plaintiff, and feel impressed that in most cases an assessment based upon 100 per cent of the original value of the taxable property, less annual depreciation, as denoted, would afford an equitable basis of taxation. But this argument ignores the plain provisions of section 169 of the Constitution of Virginia, which provides that ‘all assessments of real estate and tangible personal property shall be at their fair market value.’ ”
There the court held that the company’s real estate should be assessed at its fair market value, tempered by the manner in which other real estate in its community was assessed. That, however, is wholly apart from net income for a current year.
In Warwick County v. Newport News, supra, it appeared that $75,354.20 was set aside for such a purpose to cover an eighteen-month period.
In forms for corporate income tax returns prepared by the Commonwealth, among deductions there allowed is this provision:
“19. Depreciation.—Fill in Schedule H and enter as Item 19 [624]*624the amount claimed as depreciation resulting from the exhaustion, wear and tear, or obsolescence, of the property used in the trade or business. The law provides that only a reasonable allowance is deductible as such depreciation. It also provides that no deduction shall be allowed for any amount expended in restoring property or in making good the exhaustion thereof for which an allowance is or has been made. (Sections 25 and 26, Tax Code of Va.)”
Such an allowance is proper and is sustained by the overwhelming weight of authority, although it was not made in Newport News v. Warwick County, supra.
In the instant case, wooden conduits rot, electrolysis sets in and iron mains rust away. Pumps and provisions for purification become obsolete or give place to more efficient instrumentalities. Silt accumulates and the plant becomes outworn. This slow deterioration cannot be covered by current repairs and replacements, and so if note be not taken, the city in time will find itself without water and without water works. Construction would have to begin anew.
The city has also been charged with an annual item of $148,000, services to itself, such as fire protection, sewer flushing, street cleaning, etc. As a matter of fact, water used for these purposes at current rates would cost less than $5,000. Unquestionably the city is benefited by such service and profits by it. Pestilence might set in from unflushed sewers and the first fire that started might burn the city down, and this applies alike to the city itself and to contiguous built-up suburbs. Not a dollar of profit from this source has come into the treasury and no extravagance is charged in the maintenance of the service, which is distinctly governmental.
“No higher police duty rests upon municipal authority than that of furnishing an ample supply of pure and wholesome water for public and domestic uses. The preservation of the health of the community is best obtained by the discharge of this duty, to say nothing of the preservation of property from fire, so constant an. attendant upon crowded conditions of municipal life.” Columbus v. Mercantile Trust & Deposit Co., 218 U. S. 645, 658, 31 S. Ct. 105, 109, 54 L. Ed. 1193.
[625]*625The principle which we rely upon is forcefully set out in an opinion of the Supreme Court of date March 15, 1937, where it is said:
“We conclude that the acquisition and distribution of a supply of water for the needs of the modem city involve the exercise of essential governmental functions, and this conclusion is fortified by a consideration of the public uses to which the water is put. Without such a supply, public schools, public sewers so necessary to preserve health, fire departments, street sprinkling and cleaning, public buildings, parks, playgrounds, and public baths, could not exist. And this is equivalent, in a very real sense, to saying that the city itself would then disappear.” William Whitlock Brush v. Commissioner of Internal Revenue, 300 U. S. 352, 57 S. Ct. 495, 500, 81 L. Ed.-.
“* # * water works are held in trust for public purposes * * *.” Commonwealth v. Richmond, supra.
This conclusion, as the Brush Case tells us, is not in conflict with those cases which hold cities liable in tort for negligence in the conduct of this business.
The city should not be penalized because it has discharged with fidelity a public trust.
It was never intended by the city that its water works system should be a source of profit. That charge against it and these paper profits are as unsubstantial as a Barmecide feast.
With depreciation charges added and with those for fire protection stricken out, under no plausible basis of calculation can a profit be established against the city for any of the years here in judgment.
The city, under act approved March 3, 1924 (Acts of Assembly, 1924, ch. 87, p. 88), constructed a water main to Virginia Beach at a cost of $200,000. For this outlay Virginia Beach was to pay $12,000 a year, which said statute declared to be interest on the outlay. This was not a city profit, and if it were so declared, it would not affect the conclusions we have heretofore reached.
If the county of Nansemond were to prevail in this litigation, then Isle of Wight and all other counties from which it [626]*626draws its water supply would of course be entitled to equal relief.
In conclusion, we again draw attention to a policy of the State which has always prevailed: Taxes are not to be assessed against it or its subdivisions unless the right to tax is made plain. Nor is this affected by the fact that county property may be withdrawn from taxation. Rudacille v. State Commission, 155 Va. 808, 156 S. E. 829. In the Shenandoah Park hundreds of thousands of acres are in this manner exempt.
The judgment of the court below should be reversed and the cause remanded. It is so ordered.
Reversed and remanded.
Campbell, C. J., and Hudgins and Spratley, JJ., dissenting.