[786]*786MEMORANDUM OPINION AND ORDER
ROVNER, District Judge.
I. INTRODUCTION
Pending before the Court is the motion of defendant County of DuPage (“Du-Page”) for a directed verdict. For the reasons set forth below, the Court denies the motion.
II. ANALYSIS
Because this is a diversity case, the Court must look to Illinois law for guidance on the defendant’s motion for directed verdict. See Consolidated Bearings Co. v. Ehret-Krohn Corp., 913 F.2d 1224, 1227 (7th Cir.1990). The Illinois standard for such verdicts is set forth in Pedrick v. Peoria & Eastern R.R. Co., 37 Ill.2d 494, 510, 229 N.E.2d 504, 513-14 (1967), where the Illinois Supreme Court remarked:
[VJerdicts ought to be directed ... only in those cases in which all of the evidence, when viewed in its aspect most favorable to the opponent, so overwhelmingly favors movant that no contrary verdict based on that evidence could ever stand.
See Consolidated Bearings, 913 F.2d at 1224; Schultz v. American Airlines, Inc., 901 F.2d 621, 623 (7th Cir.1990). Having heard the evidence presented in plaintiffs' case, the Court cannot conclude that the evidence so overwhelmingly favors defendant that a verdict in plaintiffs’ favor could not stand.
A. Inverse Condemnation Claim
DuPage initially argues that it is entitled to a directed verdict on plaintiffs’ claim for inverse condemnation because plaintiffs have established that the Warner property was flooded on only two occasions. This argument is premised upon a line of cases which holds that real property cannot be deemed “taken” unless the property is flooded frequently or continuously. See, e.g., Starcevich v. City of Farmington, 110 Ill.App.3d 1074, 443 N.E.2d 737, 741, 66 Ill.Dec. 811, 815 (3d Dist.1982) (complaint failed to state a cause of action for taking because alleged injuries complained of were not sufficiently frequent or permanent in nature). However, DuPage’s argument misses the point in two respects. First, the Illinois constitution protects property owners from uncompensated taking or damaging. See Department of Transportation of the State of Illinois v. Rasmussen, 108 Ill.App.3d 615, 439 N.E.2d 48, 54, 64 Ill.Dec. 119, 125 (2d Dist.1982). This Court has previously ruled that the infrequency of the flooding at issue in this case precludes a claim for taking, but leaves room for a claim of damaging. (Memorandum Opinion and Order of June 23, 1986 at 4.) Although, as DuPage argues, there are some eminent domain and inverse condemnation cases in which the finding of damage was based upon acts or events of a permanent nature, see, e.g., Rasmussen, 439 N.E.2d at 54-55, 64 Ill.Dec. at 125-26 (recognizing damage claim for impairment of access to property resulting from construction of highway overpass), a claim for damage may also stand upon acts or events which are transient. DuPage not only overlooks the distinction between taking and damage but the differing effects which flooding has upon real and personal property. Real property can only be deemed “taken” by flooding which occurs on a frequent or continuous basis, because isolated or intermittent flooding does not deprive its owner of the use and enjoyment of the property. When the property is personal, however, one flood may be more than sufficient to cause permanent damage or destruction. Thus, cases from other jurisdictions have recognized inverse condemnation claims for injury to personal property which arose from infrequent flooding. See Hawkins v. City of La Grande, 102 Or.App. 502, 795 P.2d 556, 558-59, review allowed, 310 Or. 547, 800 P.2d 789 (1990) (rejecting contention that single incident of flooding can never result in compensable taking; although temporary flooding of plaintiffs’ property did not support an inverse condemnation for taking of plaintiffs’ land, it did support such a claim for the taking of plaintiffs’ personal property destroyed in the flooding); Skeen v. State, 550 S.W.2d 713 (Tex.Civ.App.1977) (finding owner entitled to judgment on inverse condemnation for water damage to real and [787]*787personal property which resulted when her land was flooded on two occasions due to elevation of nearby highway and design of adjacent culverts and service roads). Plaintiffs, through the testimony of Warner employees A1 Abrams, C. Robert Mascari and Larry Stanley, have presented ample evidence that the flood damage which occurred to the albums, cassette tapes, and other items stored in the Warner warehouse in July and August, 1982 was irreparable. Such evidence suffices to permit plaintiffs’ inverse condemnation claim to reach the jury.
DuPage briefly suggests two concerns which purportedly counsel against the recognition of inverse condemnation claims in cases like this one: (1) that there is apparently no Illinois decision explicitly recognizing an inverse condemnation claim for injuries to personal property; and (2) that recognition of such a claim would open the floodgates to similar claims in other cases. However, DuPage has cited no case from any jurisdiction which rejects inverse condemnation claims based upon damage to personal property, nor has it marshalled any argument contrary to the many cases from other jurisdictions which have recognized such claims. See Memorandum Opinion and Order of March 4, 1991 (denying DuPage’s motion for judgment on the pleadings as to Count II of plaintiffs’ third amended complaint) at 3-4, 1991 WL 32775.1 The mere fact that Illinois has not yet expressly acknowledged this species of inverse condemnation claims does not suggest a reluctance to do so, nor does it supply a valid basis for this Court to dismiss the claim, as DuPage would apparently have the Court do.2
DuPage’s concern that the recognition of inverse condemnation claims for the loss of personal property will burden local governments with a new and expansive breed of liability is unfounded. Other jurisdictions have accepted such claims without evident fiscal calamity. Moreover, DuPage’s suggestion that recognition of such claims will subject local governments to claims for injuries to personal property in all types of circumstances — automobile accidents involving governmental employees, for example (see Motion for Directed Verdict at 6)— is unfounded. DuPage ignores the fact that the particular proof required by an inverse condemnation — the taking or damaging of property proximately caused by a public improvement — limits such claims to a relatively narrow range of circumstances.
B. Duty to Undertake a Drainage Analysis
DuPage contends that it cannot be held to any duty to undertake a drainage analysis insofar as such analysis would have affected the modifications which it made in 1978 to Thorndale Road and the culvert below and which, according to plaintiffs, was a proximate cause of the flooding which gave rise to this litigation. This dispute has arisen in the context of the “issues” jury instruction plaintiffs have [788]*788modeled after Illinois Pattern Jury Instruction (Civil) No. 20.01. There, plaintiffs contended that DuPage was negligent in the design and construction of the widened roadway and extension and modification of the culvert because, inter alia, DuPage failed to undertake a drainage analysis to assess the impact of the changes it made. See Plaintiffs Proposed Jury Instruction No. 39, ¶ (g); Defendant’s Revised Proposed Jury Instruction No. 13 at 1, H (d). DuPage contends that such a contention is improper in light of the well-established principle that Illinois municipalities have no duty to undertake public improvements. See, e.g., City of Freeport v. Isbell, 83 Ill. 440, 442 (1876). However, as DuPage itself acknowledges, once a municipality undertakes to construct or modify a public improvement such as Thorndale Road or the culvert beneath it, the municipality has a duty to ensure that the improvement is reasonably safe. See County of DuPage’s Memorandum of Law in Support of the County’s Objection to Paragraph D of Revised Jury Instruction Number 39 at 1-2. See also Resnik v. Michaels, 52 Ill.App.2d 107, 110, 201 N.E.2d 769, 770 (1st Dist.1964) (“A municipality is responsible for the negligent construction of public works and for its failure to maintain them, but it is not obligated, and is not liable for its neglect or refusal, to undertake such projects.”); accord Ross v. City of Chicago, 168 Ill.App.3d 83, 522 N.E.2d 215, 218, 118 Ill.Dec. 760, 763 (1st Dist.1988). Given the evidence presented in this case, Du-Page’s concern is not well founded.
Plaintiffs’ contention is not that DuPage was bound in the abstract to undertake a drainage analysis and ascertain what actions were required to improve the drainage conditions of the watershed feeding into the Thorndale Road culvert. Rather, plaintiffs argue that in raising the roadway and extending and modifying the culvert, DuPage failed to consider (by means of a drainage analysis) what impact the changes might have upon the existing drainage conditions in the area, and that the modifications which the County made rendered the culvert unsafe. This argument is supported by testimony from plaintiffs’ expert witness, Robert Gudmundson, to the effect that the flow capacity of the culvert was diminished by the addition of 90-degree bends and that the elevation of flood water waiting to pass through the culvert was increased by the elevation of the roadway.3 The jury, of course, must decide whether the improvements which DuPage undertook in 1978 were effectively “unsafe.” However, plaintiffs’ contention that they were, and that consequently DuPage is liable in negligence, is contrary neither to the law nor to the evidence presented in plaintiffs’ case. The Court has modified the jury instruction regarding the issues in the case to delete allegations which might have suggested a duty on the part of DuPage to take affirmative action separate and apart from the improvements it had undertaken to make to Thorndale Road and the underlying culvert. DuPage’s concerns in this regard have therefore been allayed.4
C. Proximate Cause
DuPage argues that there is a lack of evidence suggesting that the 1978 modifications to Thorndale Road and the culvert were a proximate cause of the flooding of the Warner property. That contention holds no merit. Gudmundson testified repeatedly that based upon his study of the conditions in the area and upon data for a 30-year rainfall, the post-1978 elevation of [789]*789the roadway and configuration of the culvert caused the flooding.5 Nonetheless, DuPage suggests that the requisite evidence of proximate cause is absent because such testimony is based, to a certain degree, upon suppositions as to what occurred on the events in question. This argument ignores the fact that findings of negligence are often based upon post facto recreations of events which necessarily rely to some extent upon theories and assumptions as to what likely occurred, as opposed to definitive proof of what actually occurred. The only limitation upon evidence in this regard is that expert opinion upon causation must be expressed to a reasonable degree of scientific certainty. See Memorandum Opinion and Order of February 17,1991 at 25, citing, inter alia, Rodrian v. Seiber, 194 Ill.App.3d 504, 507, 551 N.E.2d 772, 773-74, 141 Ill.Dec. 585, 586-87 (5th Dist.1990) (although an “expert may not state a judgment or opinion based on conjecture,” “an expert opinion couched in terms of probabilities or possibilities based upon certain assumed facts is not improper or inadmissible”). DuPage does not argue that the expert testimony offered in this case fails to meet this criterion. To the contrary, both of the experts who testified on behalf of the parties indicated without reservation that they were able to offer their opinions to a reasonable degree of engineering certainty based upon the data available to them. Accordingly, there is nothing fatally deficient the proof of negligence which plaintiffs have tendered.
D. Statutory Immunity
DuPage argues that its course of conduct with respect to its 1978 work upon Thorndale Road and the culvert is cloaked with immunity pursuant to the Illinois Local Governmental and Governmental Employees Tort Immunity Act, Ill.Rev.Stat. ch. 85, §§ 2-103, 3-102(a), 3-103 (1981) (the “Act”).6 As this Court noted in its June 27, 1989 opinion denying DuPage’s motion for summary judgment, under the version of the Act in effect at the time of the events underlying this case, a local government waived its immunities and defenses under the Act by purchasing liability insurance as DuPage had. See Memorandum Opinion and Order of June 27, 1989 at 8, 1989 WL 75184; see also Ill.Rev.Stat., ch. 85, 119-103(c) (1981).7 Nonetheless, DuPage argues that to the extent it maintained a self-insured retention for liability below a certain amount, it does not waive the immunity defenses otherwise available under the Act. As set forth below, the Court deems that argument to have been waived. Alternatively, the Court concludes that such defenses would not require a directed verdict in DuPage’s favor, because the premises for liability in this case are not [790]*790contrary to the provisions of the Act upon which DuPage relies.
1. Waiver of Statutory Immunity via Purchase of Insurance
DuPage correctly argues that any waiver of immunity under the former version of 119-103(c) is co-extensive only with the amount of its insurance coverage; in other words, to the extent a local government is self-insured, it has not waived its statutory immunity from an award of damages. As the Illinois Supreme Court explained in Antiporek v. Village of Hillside, 114 Ill.2d 246, 499 N.E.2d 1307, 1308, 102 Ill.Dec. 294, 295 (1986):
Tort immunity is intended to protect governmental funds, assuring that they will be directed and used for governmental purposes. If, however, the municipality decides to protect individuals against its negligent conduct by acquiring commercial insurance, the immunity is waived since government funds are no longer in jeopardy and immunity would inure to the benefit of private investors who have assumed the risk of insurers. Conversely, when a municipality self-insurers [sic], it bears all risks itself, and settlements or awards are paid directly from government coffers. Section 9-103(c) does not come into play in such circumstances because there is no concern that private investors, paid to assume certain risks, will attempt to assert immunities and shirk responsibilities they have assumed.
(Citations omitted.) This same principle applies when a local government has obtained commercial insurance for liability beyond a certain amount, but is self-insured for liability below that amount. See Carr v. City of Chicago, 630 F.Supp. 932, 936 (N.D.Ill.1986) (Shadur, J.) (“§ 9-103(e) provides for the insurer’s waiver only ‘within the limits of said policy....’ Illinois courts construe the scope of the waiver coextensively with the type and amount of damages the insurance policy covers.”); Beckus v. Chicago Board of Education, 78 Ill.App.3d 558, 397 N.E.2d 175, 33 Ill.Dec. 842 (1st Dist.1979) (where defendant was insured for liability in excess of $1 million and maintained a self-insurance retention for liability up to that amount, defendant had not waived its statutory immunity from liability below $1 million); Collins v. School District No. 189, St. Clair County, 115 Ill.App.3d 100, 450 N.E.2d 387, 389, 70 Ill.Dec. 914, 916 (5th Dist.1983) (where insurance policy excluded liability for punitive damages, defendant had not waived liability as to claims for such damages in purchasing the insurance). DuPage represents without contradiction from plaintiffs that it maintained a self-insured retention of $100,000 for each event within the scope of its insurance policy, or a total of $200,000 for the two flood events at issue in this case. Thus, DuPage contends that its statutory immunity remains intact up to the amount of $200,000. For two reasons, this argument fails.
First, although this case has been pending for nearly eight years, DuPage has not raised this argument until now. The issue was not raised in DuPage’s motion for summary judgment (indeed, as the Court noted in denying that motion, DuPage did not rely upon the provisions of the Act at all, see Memorandum Opinion and Order of June 27, 1989 at 8); it was not raised in DuPage’s trial memorandum, nor was it raised in the pretrial order. Plainly this was not an argument the merits of which depended upon the evidence which plaintiffs would produce at trial; consequently, there is no excuse for the failure to assert this argument at an earlier date. Indeed, shortly before trial, plaintiffs moved to strike the statutory immunity defenses which DuPage had belatedly included it its affirmative defenses. When DuPage appeared in court upon the motion on November 13, 1990, the Court inquired of Du-Page’s counsel how it intended to proceed upon these defenses and expressed the concern that such defenses might raise legal issues which should be resolved in advance of trial. In response, DuPage’s counsel made no mention of the argument it raises now. Subsequently, in its decision denying the motion to strike the affirmative defenses, the Court observed:
[791]*791The Court does have some concerns as to what, if anything, DuPage plans to make of the immunity defenses. Du-Page has not filed any dispositive motion based upon these defenses, and the date for such motions has long since passed. Moreover, the Court has previously noted in dictum in this litigation that the assertion of immunity under the Illinois Local Governmental and Governmental Employees Tort Immunity Act is barred where, as here, the governmental entity has purchased liability insurance. See Memorandum Opinion and Order of June 27, 1989 at 7-8. Thus, it is not at all clear why DuPage has invoked this act. DuPage should, of course, be fully 'prepared to address the relevance of its statutory immunity defenses and the manner in which they must be addressed in the forthcoming pretrial order. Should the Court subsequently ascertain that these defenses require pretrial motions which DuPage has not filed or that the resuscitation of these defenses in response to the second amended complaint poses undue burdens which have not been called to the Court’s attention, the court may reconsider this ruling and determine that DuPage has indeed waived these defenses.
(Memorandum Opinion and Order of December 14, 1990 at 5-6, 1990 WL 251896; footnote omitted, emphasis added.) Du-Page offers no excuse for its failure to raise this argument until now, and in light of the Court’s explicit instruction to address the implications of the immunity defenses in the pretrial materials, there can be none. The Court went to great lengths to ensure that the plethora of legal issues raised by the parties were briefed, argued, considered, and resolved prior to trial.8 Repeatedly the Court admonished the parties that it did not want issues which could have been foreseen earlier asserted for the first time in the midst of trial.9 A fair trial demands that both the parties and the Court have the opportunity to address questions of liability in a timely and complete manner; toward that end, the parties must honor the deadlines imposed for raising the kind of argument DuPage now makes in support of its request for a directed verdict. DuPage has had every opportunity to raise the question of self-insurance; at this late date, it has foregone that opportunity. Consequently, any immunity defenses under the Act which might have been asserted to the extent of DuPage’s self-insured retention have been waived.
2. Merits of the Statutory Immunity Defenses
Even if the Court were to assume that DuPage enjoyed any immunity under the Act, such immunity would not compel a directed verdict under any of the sections of the Act which DuPage has cited.
a. § 3-103(a)
Section 3-103(a) of the Act provides:
A local public entity is not liable under this Article for an injury caused by the adoption of a plan or design of a construction of, or an improvement to public property where the plan or design has been approved in advance of the construction or improvement by the legislative body of such entity or by some other body or employee exercising discretionary authority to give such approval or where such plan or design is prepared in conformity with standards previously so approved. The local public entity is liable, however if after the execution of such plan or design it appears from its use that it has created a condition that is not reasonably safe.
[792]*792Ill.Rev.Stat, ch. 85, ¶ 3-103(a) (1981). Du-Page argues that because the design of the improvements to Thorndale Road and the underlying culvert involved the exercise of judgment on the part of DuPage engineers and other employees, DuPage is immune from liability for injuries resulting from that design. However, by the express terms of the final sentence of this section, this immunity does not extend to designs which result in an unsafe condition. Both the allegations of plaintiffs’ complaint and the evidence plaintiffs have produced at trial reveal that it is plaintiffs’ contention that the design which DuPage adopted for the 1978 improvements interfered with the drainage in the watershed within which the Warner property is located and caused the property to flood. Accordingly, § 3-103(a) does not bar plaintiffs’ negligence claim.
b. § 3-102(a)
Section 3-102(a) of the Act provides:
Except as otherwise provided in this Article, a local public entity has the duty to exercise ordinary care to maintain its property in a reasonably safe condition for the use in the exercise of ordinary care of people whom the entity intended and permitted to use the property in a manner in which and at such times as it was reasonably foreseeable that it would be used, and shall not be liable for injury unless it is proven that it has actual or constructive notice of the existence of such a condition that is not reasonably safe in sufficient time prior to an injury to have taken measures to remedy or protect against such condition.
Ill.Rev.Stat., ch. 85, Tí 3-102 (1981). Du-Page asserts that plaintiffs have presented no evidence tending to show that DuPage had actual or constructive notice of any problem in the design of the culvert or Thorndale Road prior to the flooding of the Warner warehouse in 1982. The Court disagrees.
As DuPage itself points out (Motion for Directed Verdict at 12), the Village of Ben-senville’s engineer, John Wentworth, notified DuPage employee Glen Matz in 1981 that a blockage of sticks had accumulated in the culvert and that Matz subsequently removed the blockage. Such evidence tends to show that DuPage, through its employee, had notice of a problem which both Matz and Gudmundson believed was one potentially enhanced by the bends in the culvert which were installed by DuPage in 1978.10
In addition, as plaintiffs point out, Went-worth testified that he and Matz had discussed alternative means of eliminating the bends in the culvert. Wentworth also testified that he had sent a letter to Matz proposing a second, 36-inch culvert adjacent to the existing culvert under Thorn-dale. Several other witnesses testified to ongoing discussions between Bensenville and DuPage regarding measures to alleviate a perceived inadequacy in the existing culvert. Accordingly, plaintiffs have presented sufficient evidence of notice to DuPage regarding the purported defects in the culvert to meet the requirements of § 3-102(a).
c. § 2-103
DuPage also invokes § 2-103 of the Act, which provides:
A local public entity is not liable for an injury caused by adopting or failure to adopt an enactment or by failing to enforce any law.
Ill.Rev.Stat., ch. 85, § 2-103 (1981). Du-Page cites this provision out of concern that plaintiffs might argue, based upon evidence indicating that the Warner warehouse was built lower than Bensenville building ordinances required, that DuPage had some responsibility to ensure that Ben-senville properly enforced its building codes and ordinances. No such argument has surfaced to date, and in response to DuPage’s motion plaintiffs have disavowed any intent to make it. Accordingly, § 2-103 is inapposite.
[793]*793E. Public Official Immunity
Finally, DuPage invokes the common law doctrine of public official immunity. See, e.g., Ten Eicken v. Johnson, 1 Ill.App.3d 165, 273 N.E.2d 633, 636 (1st Dist.1971); Lusietto v. Kingan, 107 Ill.App.2d 239, 246 N.E.2d 24, 27 (3d Dist.1969). DuPage argues that because this doctrine would protect the designers of the 1978 improvements to Thorndale Road from liability arising from these improvements, the County as their employer enjoys comparable immunity. For several reasons, this contention is erroneous.
As a threshold matter, DuPage’s invocation of common law immunities is inappropriate. “In Illinois, municipalities and their employees enjoy no immunity from suit, except as provided by the Act.” Melbourne Corp. v. City of Chicago, 76 Ill.App.3d 595, 394 N.E.2d 1291, 1297, 31 Ill.Dec. 914, 920 (1st Dist.1979). See also Warchol v. City of Chicago, 75 Ill.App.3d 289, 393 N.E.2d 725, 729, 30 Ill.Dec. 689, 693 (1st Dist.1979) (“the liability of a municipal corporation is currently governed by the Local Governmental and Governmental Employees Tort Immunity Act”). Moreover, although the provisions of the Act have effectively codified common law immunities, see id., 393 N.E.2d at 729, 30 Ill.Dec. at 693, the express terms of the Act regarding liability cannot be ignored. Cf. Horton v. City of Ottawa, 40 Ill.App.3d 544, 352 N.E.2d 23, 25-26 (3d Dist.1976) (rejecting argument premised upon common law public official immunity, where that argument disregarded applicable provisions of the Act).
In any event, public official immunity has no bearing whatsoever upon this case. Sections 2-201, et seq. of the Act do codify the doctrine of public official immunity which existed at common law. Ul.Rev. Stat., ch. 85 ¶ 2-201, et seq. (1981); see also Ill.Rev.Stat, ch. 85 ¶ 3-103(b) (1981). Yet, as the Court pointed out in its decision denying DuPage’s motion for summary judgment, public official immunity is immaterial where, as in this case, no public official has been named as a defendant. See Memorandum Opinion and Order dated June 27, 1989 at 6 (“even a cursory reading of Warner’s amended complaint reveals that Warner is not seeking to hold any public officials ‘personally liable’ for their acts in connection with the Thorndale improvements”). Further, although § 2-109 of the Act provides that “[a] local public entity is not liable for an injury resulting from an act or omission of its employee where the employee is not liable,” Ill.Rev. Stat., ch. 85, ¶ 2-109 (1981), this provision does not operate to relieve DuPage of liability here. The same argument that Du-Page attempts to make was explicitly rejected in Horton:
Defendant argues that, under both the statute and case law, the official in charge of city streets is not liable, and therefore the city which employs him is similarly immune from liability under section 2-109, supra_
While we acknowledge the seemliness of defendant’s logic, we find that defendant would have us disregard Article III of the tort immunity statute which deals with liability for injury occurring in the use of public property....
352 N.E.2d at 25. Thus, regardless of whatever immunity the public officials and employees of DuPage might enjoy for their work in connection with the Thorndale Road improvements, DuPage itself can be subjected to liability consistent with the terms of such provisions as §§ 3-102 and 3-103, discussed above. See id. 352 N.E.2d at 25-26 (holding municipality liable for failure to maintain roadway in reasonably safe condition).11
[794]*794III. CONCLUSION
For the foregoing reasons, defendant’s motion for a directed verdict is denied.