MR. JUSTICE NORVELL
delivered the opinion of the Court.
Based upon special findings of a jury, the District Court of Young County, Texas, rendered judgment for the sum of $430,-750.00 in favor of the City of Graham and against the Brazos River Authority. The Court of Civil Appeals affirmed. 335 S.W. 2d 247.
The City’s theory of recovery was that the River Authority had taken or damaged three pieces of property owned and used by it in carrying out its municipal functions. Article 1, Sec. 17, Texas Constitution. The jury found that the City’s sewage disposal plant, its water treatment plant and its Salt Creek “channel reservoir” had all been rendered subject to flooding as a result of the “construction, maintenance and operation of Possum Kingdom Dam and the siltation * * * resulting therefrom”. It also found that the intrinsic value of the sewage disposal plant “at the present time had Possum Kingdom Dam not been constructed and maintained and operated” would have been $140,000.00, but that by reason of the construction, maintenance and operation of such dam, the value of the sewage disposal plant was only $750.00 at the present time; a difference of $139,250.00. Similar findings were made with reference to the water treatment plant, (before, intrinsic value — $250,000.00; after — $1500.00—differ-ence— $248,500.00), and the “channel reservoir” (before, intrinsic value — $43,000.00; after — none—difference—$43,000.00).
The River Authority as petitioner in this Court attacks the judgments of the courts below by nine points of error wherein it asserts that the Authority is not liable in law for injuries resulting from the flooding of any of the respondent City’s facili[170]*170ties; that as a matter of law, the evidence relating to damages will not support a recovery for the damaging or taking of the water treatment plant or the “channel reservoir”; that the City’s action is barred by the two year statute of limitations, Article 5526, Vernon’s Ann. Texas Stats.; that the District Court erroneously excluded from evidence a purported release executed by the City to the Authority, and that the trial court erroneously instructed the jury as to the measure of damages and improperly commented upon the weight of the evidence.
Petitioner under its first contention above mentioned asserts that the City as an upper riparian on the Brazos has no vested right to have the waters of the Brazos and its tributary, Salt Creek, flow by its land at undiminished speed and that it is the checking of the flow of the river by the operation of the Possum Kingdom Dam that causes siltation which in turn brings about a rise in the water level of the Brazos and Salt. Creek and results in the flooding of respondent’s property; that petitioner is entitled to use the bed and banks of the Brazos for the storage and flow of water under the statutory direction of the State, and that respondent’s lands are subject to a servitude whereby damages resulting from the State’s efforts to control flood waters cannot be recovered from the State.
The pertinent facts of the case, particularly those relating to the first argument or contention of the petitioner above mentioned, are:
The Brazos River Authority, formerly the Brazos River Conservation and Reclamation District, is a public governmental agency created directly by legislative enactment under authority of the Conservation Amendment to the Texas Constitution. See Article 16, Sec. 59, Texas Constitution, Article 8280-101, Vernon’s Ann. Texas Stats. In 1941, the Authority constructed the Possum Kingdom Dam across the Brazos in Palo Pinto County. This dam is located to the west and upstream from the City of Mineral Wells. The spillway of the dam is one thousand feet above sea level. The construction of the dam resulted in the formation of Possum Kingdom Lake which covers some 26,000 acres and extends from the dam in a generally westerly and northerly direction for some sixty-five miles up the Brazos. In order to provide for the bed and banks of such lake, the Authority secured, by purchase or condemnation, lands and easements over lands for permanent or intermittent flooding up to the 1100 foot contour mark, although this was not the invariable practice or rule. Gooseneck Bend on the Brazos is a large ox-bow [171]*171loop located approximately fifty-five miles up the Brazos from the Possum Kingdom Dam. Salt Creek flows approximately north to south and joins the Brazos at Gooseneck Bend. The City of Graham is located on the east side of Salt Creek. Its sewage disposal plant is located near the southwest corner of the city limits on the west side of the creek and about three miles up stream from the Salt Creek-Brazos confluence. This plant was built in 1923, long before the construction of the Possum Kingdom Dam, and has been improved and modernized since that time. The “channel dam” heretofore mentioned is located across Salt Creek approximately one and a quarter miles above the sewage disposal plant. This dam was built in 1908 and enlarged in 1923. It creates a small channel reservoir in Salt Creek which holds about ten acre feet of water and is used as an emergency or standby water supply for the City. The City’s water treatment plant is located on the east side of Salt Creek about 1200 feet upstream from the channel dam and about a mile and a half above the sewage disposal plant. The main source of the City’s water supply comes from two reservoirs, Lake Graham and Lake Eddleman, which are upstream from the water treatment plant and located on separate branches of Salt Creek. These lakes are connected by a canal and water is taken from them through Lake Eddleman to the water treatment plant by means of a 16 inch pipe line.
The elevation of the clarifier outlet of the sewage disposal plant is 1003.94 feet above sea level. The clarifier wall is two feet higher in elevation. The elevation of the top of the channel dam is 1009.97 feet while the engine room floor of water treatment plant is at an elevation of 1019.09 feet. When the water in Salt Creek rises above an elevation of 1003.94 feet, the sewage disposal plant is rendered inoperative with the result that raw sewage flows into the creek. When the water rises above the top of the channel dam, 1009.97, the water behind and impounded by the dam is rendered unfit for municipal use, and cannot be processed by the water treatment plant. When the water mark exceeds 1019.09 feet, the operation of the water treatment plant is severely hampered and it cannot effectively process waters from the city reservoir.
It appears that all these facilities of the City have been flooded to a more or less extent upon one or more occasions. The sewage disposal plant has been repeatedly flooded.
The nature and extent of the siltation problem in Possum Kingdom Lake is fully developed by the testimony. The head[172]*172waters of the Brazos are located in New Mexico but little or none of the water which falls in the Brazos watershed west of the caprock in West Texas reaches Possum Kingdom Lake. The Brazos watershed lying between the caprock and Goose-neck Bend is approximately 13,000 square miles. The area is semiarid and the waters drained from the basin are heavily laden with silt. For a ten-year period extending from 1924 to 1934, the river carried annually about 9,900,000 tons of silt past the Mineral Wells gauging station (about 65 miles below Gooseneck Bend) according to the measurements of the United States Geological Survey. One witness described the silt carriage load of this period as being the equivalent of 6,506 acre feet per year. For an approximate 13-year period from 1941 to 1954, the annual silt carriage measured at the South Bend gauging station (about ten miles above Gooseneck Bend and above the backwater of Possum Kingdom Lake) was considerably less, being 3,760,220 tons per year. This was explained by the presence of drought conditions during the 1941-54 period in which the water drained from the river basin was reduced from an average of 953,550 acre feet per annum for the 1924-34 period to 467,179 acre feet annually for the 1941-54 period. The average annual silt load carried over the Possum Kingdom Dam for the 1941-54 period was 88,065 tons as compared to 3,760,220 tons of silt carried into the reservoir. In other words, during a 12.71 year period ending in 1954, some 46,673,090 tons of silt was deposited in Possum Kingdom Lake. Less than three per cent of the silt carried into the Lake was taken out.
This process of siltation has resulted in the raising of the floor of the Lake above the elevation of the original bed of the river and the narrowing of the channel of the stream of the current running through the waters of the Lake. At and near the head of the Lake — around Gooseneck Bend — the siltation and sedimentation has been extremely heavy. When the flowing water of the Brazos reaches the static water of the Lake, with the consequent slowing of the speed of the waters, the heavy particles of silt known as the “bed load” are deposited resulting in the formation of sandbars and similar barriers in the bed and shores of the upper portions of the Lake.
The rise in the elevation of the level of the waters in the river and in the Lake at Gooseneck Bend is indicated by the testimony of the witness Robert Gooch. His testimony and charts showed the following water elevations in 1938 — before the construction of the dam; — in 1941, — immediately after the construction of the dam, — and in 1954, after the dam had been in [173]*173operation for some thirteen years, according to various quantities of water which would pass by a given point on the river measured in cubic feet per second.
Water flow cubic feet per second 1938 before dam was constructed 1941 immediate ly after dam was constructed 1954 — dam in operation for 13 years Difference in elevation between 1941 and 1954
10,000 990.7 1000.3 1003.4 3.1
20,000 995.3 1001.0 1006.2 5.2
30,000 998.4 1002.0 1008.5 6.5
40,000 1000.9 1003.5 1010.6 7.1
50,000 1003.9 1005.0 1012.3 7.3
This rather graphically represents the effects of the siltation occurring in the Lake. The witness Gooch also testified that based upon 19 years of data relating to the water flow of the Brazos, he estimated that under conditions as they existed in 1954-55, the water level of the Lake at the location of the City’s sewage disposal plant on Salt Creek (about three miles upstream from Gooseneck Bend) and in the vicinity of the City’s other installations, would reach an elevation of 1005 (1.1 feet above the clarifier outlet) whenever the Brazos carried a water flow of 15,000 cubic feet per second, and that a flow of 15,000 second feet or more would occur once every eight or nine months on an average. Other estimates of the witness were that a flow of 19,000 second feet would raise the elevation to 1006 feet and occur on an average of once every 11 months, that a flow of 37.000 second feet would raise the water elevation to 1010 feet (above 1009.97 feet, the elevation of the top of the channel dam) and occur on an average of once every two years and five months; that under 1954-55 lake and riverbed conditions, a flow of 100,000 cubic feet would result in a water level of 1019 feet, the approximate level of the floor of the City’s water treatment plant. Mr. Gooch stated that he had no record of a 100.000 second foot flow during the 19-year period immediately before 1954, but that “within the memory of people living in this area there have been floods on the Brazos of 100 thousand cubic feet per second, although it was not measured by the U. S. Geological Survey at that time.” He also stated on the basis of engineering knowledge of rivers, that much larger floods have occurred on rivers the size of the Brazos and that a flow of 100 thousand cubic feet per second is not much of a flow for that river because of the enormous drainage area involved, some 13.000 square miles.
Obviously the estimates as to water elevations and average [174]*174periods of flooding are approximate only. There are variables of a minor nature that also enter into these estimates and predictions. Undoubtedly the flow from the Salt Creek watershed between Lake Graham and Lake Eddleman and the creek’s confluence with the Brazos — approximately six miles- — has some effect upon the water levels in Salt Creek opposite the City’s installations, and there are minor differences in the position of the sewer disposal plant and the water treatment plant on Salt Creek which would affect in a small way the calculations of water levels. However, there is no serious conflict in the testimony relating to the rise in water elevation caused by the siltation process taking place in Possum Kingdom Lake and what has been said above gives an accurate though approximate picture of the situation.
We consider first that portion of the judgment relating to the sewage disposal plant. This represents a recovery of $139,-250.00 in damages. The court considered that a “taking” of the plant had resulted because of its being subjected to repeated floodings as a result of the construction, maintenance and operation of Possum Kingdom Dam. The judgment specifically describes the tract of land upon which the plant is located, together with easements incident thereto, and then provides that such property by force of the judgment is subjected “to an easement or servitude in favor of the Brazos River Authority so that (the Authority) may, without further liability, flood, overflow, inundate or submerge said properties by reason of the construction, maintenance and operation of Possum Kingdom Dam with the crest of the spillway gates at elevation of 1000 feet above mean sea level; and that the easement or servitude herein awarded (shall) become effective upon and only upon the payment of the damages herein awarded.”
It therefore appears that we have a proceeding in the nature of an inverse condemnation in that the Authority has taken the property of the City and now the City is attempting to recover compensation for such taking. Unless it can be said, as contended for by the petitioner, that the Authority was legally entitled to flood the City’s water disposal plant in carrying out its flood control and kindred activities, the fact of a taking can hardly be questioned. The plant was constructed before Possum Kingdom Lake came into existence. When constructed it was not subject to flood damage, except in case of the highest waters in Salt Creek, but now as a result of the existence of the Lake and its heavy siltation, the plant is subject to repeated overflows which, when present, render its operations impossible and cause raw [175]*175sewage to be discharged into the Creek and by backwater action carried up the stream along the western border of the town. Fort Worth Imp. Dist. No. 1 v. City of Fort Worth, 106 Texas 148, 158 S.W. 164, 48 L.R.A. (N.S.) 994; Chicago Rock Island & Gulf Ry. Co. v. Tarrant County Water Control and Improvement Dist. No. 1, 123 Texas 432, 73 S.W. 2d 55; Tarrant County Water Control and Improvement Dist. No. 1 v. Fowler, Tex. Civ. App., 175 S.W. 2d 694, wr. ref. w.o.m.; 2 Nichols on Eminent Domain (3rd Ed.), 236, 253, Secs. 6(1), 6.22, 6.23; 16 Tex. Jur. 436, Eminent Domain Sec. 251.
Petitioner contends that an upper riparian owner such as the City of Graham has no legal right to have the water in a stream flow at its customary rate of speed in coursing by or through his or its premises. As a corollary to this position, it is asserted that as most of the siltation in the Lake is caused by particles of soil being deposited on the bed and banks of the Lake as a result of of the diminution in the speed of the water flow, such injury as may result to the upper riparian is noncompensable. It is also urged as essentially a part of the same argument, that the bed and banks of the river are owned or subject to the control of the State and hence may be used by the Authority for water storage and flood control purposes without its being liable to the owners of the upland along the shores of the stream.
This argument so far as we have been able to ascertain has never been accepted in any jurisdiction. What it amounts to is the assertion that although the Authority would have to pay compensation under Article 1, Sec. 17 of the Constitution for those lands which would be covered with water immediately after the construction of the dam — the first filling of the lake, —any subsequent inundations caused by the maintenance and operation of the dam would be damnum absque injuria. In other words, it is an assertion that the taking and damaging of lands in addition to the taking for the original bed of the lake is justified under the police power. This question then naturally arises: The surface elevation of the lake when full in 1941, immediately after the construction of the dam would be approximately 1005 feet above sea level at a flow of 50,000 second feet,1 why then did the Authority adopt the general policy of acquiring lands for overflow purposes up to the 1010 line? The answer to this question is that, from an engineering standpoint, it may be reasonably anticipated that as the dam is used and operated [176]*176throughout the years the high water contour lines of the lake will rise,2 and that from a legal standpoint, there has been no recognition of, nor can there be a rational line of demarcation drawn distinguishing periods of high water which occur within a few days or months after the completion of the dam and are occasioned solely by the construction thereof, and floods which take place some years thereafter as a result of the operation and use of the dam for water impounding purposes. To attempt a distinction between the power of eminent domain and an exercise of the police power along this line would, as intimated by the Court of Civil Appeals, involve us in a sophistic Miltonian Serbonian Bog.
Governmental agencies and authorities are necessities. They are capable of rendering great and beneficent public services. But any appeal to the tradition of our laws which omits a decent regard for private property rights is both inaccurate and distorted. It is because of this regard that our governmental agencies and authorities in acquiring properties for their public purposes are generally required to proceed under the power of eminent domain rather than under the police power. Such a policy has not resulted in a destruction of flood control and improvement agencies in the past and there is no reason to apprehend that the continuation of such policy will prove overly costly or inimical to the American way of life in the future.
The geographical location of the City’s sewage disposal plant with reference to the artificial lake created by the erection of the dam is unusual, but the problem of damages created thereby should not operate to vary the established rule of compensation contemplated by the Constitution. It would be manifestly unjust to say that because much land and property in the lower reaches of the river and below a flood control dam would be saved from damage and destruction, the dam constructing authority should be allowed to take lands lying above the dam for water storage purposes under the police power without paying compensation therefor.
It may be that a riparian is in no position to complain of the slowing of the waters running in a stream adjoining his land — ■ when this is his sole complaint. But, that is not the case before us, nor are we concerned with the rights of riparians in and to [177]*177flood waters as was the case in Motl v. Boyd, 116 Tex. 82, 286 S.W. 458. Our problem here need not be pulverized into molecular parts in an attempt to fit it into the dictum of some particular case which was essentially concerned with a wholly different question than that now before us. Our questions may be simply restated thus: Does the operation of the dam and the consequent formation of the Lake cause the flooding of respondent’s property? This must be answered in the affirmative and thus a second question is raised: Can a valid distinction be drawn between flooding which results from the building of the dam only and flooding which occurs as a result of the construction of the dam and the resulting siltation of the reservoir acting together? Keeping the critical elevation of the sewage disposal plant in mind — 1003.94 feet, and referring to the table in the forepart of this opinion, it will be seen that a flow of more than 40,000 second feet would be required to flood the sewage disposal plant immediately after the dam was constructed. By 1954, because of siltation, a flow of slightly more than 10,000 second feet would bring the water level above the clarifier outlet of the sewage disposal plant.
In our opinion, the siltation of a reservoir to some extent is clearly foreseeable. It is indicated by the engineering testimony that the formation of silt depositions is taken into consideration as a part of the engineering problem. In Tarrant County Water Control and Improvement Dist. No. 1 v. Fowler, Tex. Civ. App., 175 SW. 2d 694, wr. ref., w.o.m., 142 Tex. 375, 179 S.W. 2d 250, the court mentioned the problem of the filling in of the channel of a stream by soil and gravel. The court said:
“This condition, (of flooding) in our opinion, will become progressively more serious, as it was shown that during the last few years, the bed of Ash Creek has half filled with sand and gravel, diminishing its carrying capacity, and, obviously, in times of heavy rainfall, will cause the water to leave its bed and spread out over the adjacent land. That these results were contemplated when the dam was erected is shown, we think, by the evidence of the engineer upon whose plans and advice the dams and reservoir were constructed.”
As to the sewage disposal plant, we are in agreement with the Court of Civil Appeals. The record establishes the fact that this installation or portions thereof will be repeatedly inundated by the back waters of the Brazos and Salt Creek. A “taking” under the constitutional provision is involved, and under our constitution the Authority is liable to pay just compensation [178]*178therefor. Article 1, Sec. 17, Texas Constitution; United States v. Dickinson, 331 U.S. 745, 67 S. Ct. 1382, 91 L. ed. 1789; Hidalgo County Water Improvement District No. 2 v. Holderbaum, Texas Com. App., 11 S.W. 2d 506.
It seems however that under the evidence, the water treatment plant and the channel reservoir are not in the same category as the sewage disposal plant. The judgment of the trial court relating to all of the City’s facilities proceeds upon the theory that they have been taken by the Authority and hence upon payment of compensation — that is, the damages assessed by the jury — the Authority is entitled to a perpetual easement over the lands occupied by such installations of the City. The Authority here persuasively presents the contention that when the sewage disposal plant of the City ceases operations, the only damage shown to the water treatment plant is a mere possibility of flooding which will not support the recovery allowed by the jury.
It is pointed out that one of the deleterious effects of the flooding of the sewage disposal plant is the contamination of the waters of Salt Creek with raw sewage. When the backwater in the creek rises above 1009.97, it flows over the dam of the channel reservoir and destroys the City’s emergency or standby water supply. In the event a break in the conduit from Lake Eddleman to the City’s water treatment plant should occur at the same time the channel reservoir was contaminated by sewage, the City would be without a safe supply of water for domestic use. At the present time there is an inter-relation between the three municipal facilities, i.e., the sewage disposal plant, the channel reservoir and the water treatment plant, but in considering damages for the taking or damaging of such properties, they must be considered separately as urged by the Authority. The City, after having been paid the sum of $139,250.00 (the amount of damages found by the jury) for the taking of its sewage disposal plant, would not be entitled to claim further damages to its channel reservoir and its water treatment plant because the City continued to operate the sewage disposal plant despite its susceptibility to repeated floodings. In arriving at the monetary recovery for the taking or damaging of the channel reservoir and the water treatment plant, we must consider the situation as if the sewage disposal plant were not in existence. Once the sewage disposal plant has been paid for by the Authority, the element of sewage contamination is removed from the picture. What we have left is damage to the channel dam and the water treatment plant caused by the rise in the level of the water (un[179]*179contaminated by raw sewage) occasioned by the construction, maintenance and operation of Possum Kingdom Dam.
There is a species of damage to land that is probably nonrecurring, or at least may not recur for some substantial length of time. Examples of this type are floods occasioned by extremely heavy or unprecedented rainfalls, coupled with some obstruction of a water course. The person responsible for the obstruction of the water course may be liable, in part at least, for the damages caused by the type of flood described. He would not however be liable to the same extent that he would be in cases of continuous or repeated floodings of land. This would be particularly so when such floodings occurred at widely spaced intervals in point of time. It is conceivable that the factual situation in this case points to a time in the future when the waters of Salt Creek would repeatedly inundate the City’s water treatment plant with its critical elevation of 1019.09 feet, but the situation has not as yet become “stabilized”, that is, it has not become sufficiently definite and certain to support the trial court’s theory of recovery.
In United States v. Dickinson, 331 U.S. 745, 67 S. Ct. 1382, 91 L. ed. 1789, the Supreme Court of the United States, in connection with a limitation question, considered a problem similar to that now before us. The United States Government did not condemn lands needed for the basin of a lake caused by the construction of a dam but “left the taking to physical events, thereby putting on the owner the onus of determining the decisive moment in the process of acquisition by the United States when the fact of taking could no longer be in controversy.” In the course of its opinion, the Court said:
“The source of the entire claim — the overflow due to rises in the level of the river — is not a single event, it is continuous. And as there is nothing in reason, so there is nothing in legal doctrine, to preclude the law from meeting such a process by postponing suit until the situation becomes stabilized. An owner of land flooded by the Government would not unnaturally postpone bringing a suit against the Government for the flooding until the consequences of inundation have so manifested themselves that a final account may be struck.”
By analogy, what was said in the Dickinson case has some application here. An admittedly difficult problem is presented and some additional statement is required. As pointed out in the forepart of this opinion, there was expert testimony that under river and lake bed conditions as they existed in 1954, a [180]*180flow of 100,000 second feet in the Brazos would be necessary to raise the water level in Salt Creek adjacent to the City’s installations to an elevation of 1019 feet, near the floor elevation of the water treatment plant, and that in the 19-year period prior to 1954, a flow of such dimensions had not occurred. There is some evidence that in 1957 the water in Salt Creek arose above the floor of the water treatment plant, although the Authority disputes the occurrence. It appears that heavy precipitation on the comparatively short watershed of Salt Creek acting in conjunction with a rise on the Brazos contributed to this rise in the level of the water. However, conceding that the watershed of the Brazos is fully capable of procuring and the river has in times past experienced a flow of 100,000 second feet in the vicinity of Possum Kingdom Lake and that the Lake’s level to some extent is affected by heavy local precipitation in the Salt Creek vicinity, that is not evidence that 1019 foot floods have become recurring and certain phenomena to the extent that we may say that a permanent, as distinguished from a sporadic damage, has taken place. There is evidence that the danger of flooding may increase with the passage of years and that engineers have advised the City to remove its water treatment plant to another location, particularly in view of the fact that much of the plant will have to be replaced because of obsolescence and an enlarged installation is required by the growth of the City. On the other hand, the plant is now in operation. It was not destroyed by the 1957 high water. The jury’s findings of damages were predicated upon an estimate which practically accounted for the entire value of the plant. In order to support the jury’s findings in this regard, it would be necessary to say that one flooding of the plant, coupled with the possibility of further floodings at uncertain and perhaps widely spaced intervals, is sufficient in law to support the award. This we cannot do without entering the realm of conjecture, speculation and guess work. It may be entirely possible that the water treatment plant could be used for years to come without another re-flooding or until, by ordinary wear and tear and natural obsolescence, it had become unsuitable for the purpose for which it was constructed. It would seem that the safer rule to follow is one requiring the plaintiff in actions such as this to establish definitely by evidence above the dignity of conjecture that the damage claimed is the result of a repeated and recurring injury rather than a sporadic one. Until a plaintiff is in position so to establish the repetitious nature of the injury, he should be confined in his demand for damages to those flowing directly from the single injury or flooding.
[181]*181The evidence here relied upon to establish a complete destruction (for all practical purposes) of respondent’s water treatment plant “fails to give any certain or reliable basis for the recovery sought and the verdict rendered but left the jury to wander through the domain of surmise and speculation in order to reach the verdict rendered.” Fort Worth & Denver City Ry. Co. v. Speer, Texas Civ App., 212 S.W. 762, 765, no wr. hist.
In Austin & N. W. Ry. Co. v. Anderson, 79 Texas 427, 15 S.W. 484, a case dealing primarily with a limitation question, this Court discussed the various types of actions arising from the flooding of lands because of the erection of structures along or across water courses. In speaking of occasional injuries resulting from sporadic high waters the Court said: “But where it (the damage) is not permanent, but depends on accidents and contingencies so that it is of a transient character, successive actions may be brought for injury as it occurs; * * This temporary type of injury mentioned in the Austin case is all that the evidence here suggests. A case for permanent injury such as envisioned by the jury verdict has not yet matured. See also, Baker v. City of Fort Worth, 146 Texas 600, 210 S.W. 2d 564, 5 A.L.R. 2d 297.
While the evidence shows that the channel reservoir by reason of the lower elevation of its dam will be flooded more often than the water treatment plant, it is not shown that in the absence of the creek’s backwater being contaminated with sewage, the channel reservoir would be seriously affected by the presence of ordinary flood waters therein. It certainly would not be totally destroyed as found by the jury.
We next consider the Authority’s claim that the City’s action is barred by the two year statute of limitations. Article 5526, Vernon’s Ann. Texas Stats. The City, in turn, points out that in 1953 the Legislature amended Article 5517 of the Revised Statutes so as to read as follows:
“The right of the State, all counties, incorporated cities and all school districts shall not be barred by any of the provisions of this Title, nor shall any person ever acquire, by occupancy or adverse possession, any right or title to any part or portion of any road, street, alley, sidewalk, or grounds which belong to any town, city, or county, or which have been donated or dedicated for public use to any such town, city or county by the owner thereof, or which have been laid out or dedicated in any manner to public use in any town, city or county in this [182]*182State.” (Italics supplied.) See Article 5517, Vernon’s Ann. Texas Stats.
The Title referred to in said Article 5517 is Title 91 relating to Limitations. The Authority argues that the Legislature meant to refer to Chapter 1 of Title 91 which contains only the limitation articles relating to suits for land. This brings to mind the maxim that “If Parliament does not mean what it says, it must say so.”3 Newton v. Barnes, Texas Civ. App., 150 S.W. 2d 72, wr. ref. If we were to approach the problem from the standpoint of the wisdom of the Legislature enactment, we could perhaps conclude that the Legislature may have had real property limitations only in mind. But this is an approach which may not be employed by the courts. We may not invade the legislative field. 50 Am. Jur., 212, Sec. 228. There is nothing ambiguous or uncertain about the literal meaning of the Act and hence no need to explore its legislative history. The Act simply states that, “The right of the State, all counties, incorporated cities and all school districts shall not be barred by any of the provisions of this Title, * * Article 5526 is a part of the Title of the Revised Statues referred to. “The rule permitting departure from the literal meaning has no application at all where the statute is unambiguous and embodies a definite meaning and the intention of the legislature as expressed in the law is reasonably free from doubt.” 50 Am. Jur. 239, Statutes, Sec. 241. The amended act has remained on the statute books unchanged in wording since 1953, and we are not at liberty to depart from the literal meaning of the article at this time.
We might add, however, that insofar as the sewage disposal plant is concerned, we have a taking by inverse condemnation and the great weight of American authority supports the position that, absent a particular statute covering the situation, the land limitation rather than the general limitation statutes apply to such inverse condemnation proceedings. Ackerman v. Port of Seattle, 55 Wash. 2d 400, 348 P. 2d 664; Aylmore v. City of Seattle, 100 Wash. 515, 171 Pac. 659; Oklahoma City v. Wells, 185 Okl. 369, 91 P. 2d 1077; cases collected in Annot., 123 A.L.R. 676; 18 Am. Jur., Eminent Domain, Sec. 394. The Texas [183]*183rule is in accord. In case of a “taking” of property, the City’s right thereto would not be barred if ever until the expiration of the ten year period necessary to acquire lands by adverse possession under Art. 5510, Vernon’s Ann. Texas Stats. Tarrant County Water Control and Improvement Dist. No. 1 v. Fowler, 175 S.W. 2d 694, Texas Civ. App., wr. ref. w.o.m., 179 S.W. 2d 250. See also, Tarrant County Water Control and Improvement Dist. No. 1 v. Reid, 203 S.W. 2d 290, wr. ref. n.r.e.
There was no error in the trial court’s action in excluding from evidence a deed from the City to the Authority which contained a purported release. The conveyance of a small tract of 3.94 acres described in the deed is immaterial to any issue in the present case. Such deed was evidently prepared by using a printed form and was dated in January of 1939. It bore the signature of the then mayor of the City of Graham. The release provision contained therein read as follows:
“The Grantor, for himself and his successors in title, hereby releases the Grantee from liability for damages resulting from overflowing or flooding any other lands owned by him occasioned by the construction, operation or maintenance of said Possum Kingdom Dam, including, but not limited to, the following lands:”
It was recited in the deed that the mayor was acting under authority of a resolution by the City Council. This resolution authorizes the mayor to “execute a proper deed of conveyance of the interest of the City of Graham to said property (the 3.94 acres), the same to be duly attested by the city secretary and the corporate seal thereto affixed”. The deed was not signed by the city secretary nor was the corporate seal affixed thereto. These circumstances are probably immaterial in that the resolution does not authorize the mayor to execute any release, covenant, contract or other written instrument than a conveyance of the specified property. It has been held that an authorization to “make a deed” empowered a mayor to insert a covenant of general warranty into the deed. Abbott v. City of Galveston, 97 Texas 474, 79 S.W. 1064. However, we find no authority and know of no general agency principles which would empower a mayor, authorized simply to “execute a deed”, to also execute such a sweeping release from liability for flooding all of respondent’s other lands as asserted here by petitioner. To the contrary, it appears that whenever a mayor exceeds his delegated authority to contract, the city is not bound, except perhaps in certain cases to the extent of benefits already received. City of [184]*184Bryan v. Page, 51 Texas 532; City of Laredo v. Macdonnell, 52 Texas 511; Penn v. City of Laredo, Texas Civ. App., 26 S.W. 636, no writ hist.; City of Tyler v. Adams, Texas Civ. App., 62 S.W. 119, no writ hist.; Indiana Road Mach. Co. v. City of Sulphur Springs, Texas Civ. App., 63 S.W. 908, no writ hist.; 30-A Tex. Jur.; Municipal Corporations, Sec. 449. There is nothing in the record which would support a finding of estoppel or ratification by respondent city of the unauthorized release. Article 974d-5 has no relevance to the present factual situation.
We are further of the opinion that no reversible error is shown in connection with the special instructions given by the trial court with reference to the damage issues. As heretofore pointed out, special issues were submitted to the jury relating to the depreciation in the intrinsic value of the sewage disposal plant and the water treatment plant of the City caused by the construction, maintenance and operation of the Possum Kingdom Dam. In this connection, the trial court defined “intrinsic value” so as to authorize the jury to consider such matters as replacement cost, depreciation, anticipated serviceable life, general usefulness, and such other matters as have a bearing upon the actual value of the property. The jury was further instructed that in considering the value of these plants it was “not to consider the possibility of constructing levees or dykes around the plaintiff’s sewage disposal plant or water treatment plant”. Petitioner claims that this latter instruction was prejudicial and constituted a comment upon the evidence. We do not agree.
Had petitioner been entitled to any issues on mitigation of damages, it may well have been relevant to consider the possibility of erecting protective dykes and levees around respondent’s plants. But nothing in petitioner’s trial pleadings pertains to mitigation of damages, and thus the right to demand a submission of this affirmative defense was waived. Rule 94, Texas Rules of Civil Procedure. Indeed, petitioner seems to have recognized this in the trial court, as its attorneys expressly stated that evidence of the feasibility of dykes and levees was being preferred solely to show that respondent was not maintaining “up-to-date” plants.
In seeking to determine the actual intrinsic value of these plants, it was not relevant to consider what respondent might have done to make them more or less valuable. The jury was properly instructed to consider the value of the plants as they were, and not as they could have been. No one disputes the fact that these plants have been operated without levees for many [185]*185years, and it was quite possible for the jury to find that this absence of levees lowered the intrinsic value of the plants. Nothing in the trial court’s instructions would have prevented it from so doing and hence no prejudicial error is presented.
The cause of action relating to the taking of the City’s sewage disposal plant is severable from those asserting a claim for damages to the City’s channel reservoir and water treatment plant. The judgment of the Court of Civil Appeals insofar as it affirms the judgment of the trial court for a recovery of $139,-250.00 as and for the taking of the City’s sewage disposal plant is affirmed. As to the claims asserted against the Authority by reason of alleged injuries to the City’s channel reservoir and water treatment plant, the judgments of the Court of Civil Appeals and the trial court are reversed and this cause insofar as it embraces such claims is remanded to the trial court for further proceeding not inconsistent with this opinion.
Opinion delivered October 3, 1961.