SPINA, J.

In the present case, here on direct appellate review, we consider whether the tort of private nuisance falls within the purview of the Massachusetts Tort Claims Act (Act), G. L. c. 258, and, if so, whether such a claim brought by John N. Morrissey, on behalf of the JNM 2006 Trust, against, among others, the Executive Office of Transportation and Public Works (Commonwealth)3 is barred by the exceptions to the waiver of sovereign immunity set forth in G. L. c. 258, § 10 (b) and (e). For the reasons that follow, we conclude that an action for private nuisance against the Commonwealth is subject to the provisions of the Act, and that Morrissey's claim, arising from certain construction activities on a State highway, is barred by statutory exceptions to the waiver of sovereign immunity.

1. Background. For the purposes of our review, we accept as true the allegations in Morrissey's amended complaint. See Iannacchino v. Ford Motor Co., 451 Mass. 623, 636 (2008), quoting Bell Atl. Corp. v. Twombly, 550 U.S. 544, 555-556 (2007). Morrissey, as the attorney for and sole trustee of the JNM 2006 Trust, holds legal title to a six-acre property at 23 Cambridge Turnpike in Lincoln (Trust property), where Morrissey's father lives. The Trust property's only access to a public way is a driveway onto the Cambridge Turnpike, also known as Route 2, a State highway. New England Deaconess Association—Abundant Life Communities, Inc. (Deaconess), owns the land that abuts the Trust property. The primary means of vehicular access to the Deaconess property is a paved road along the side of its property that exits onto Route 2. Prior to the commencement of road work, Route 2 in the vicinity of the Trust and Deaconess properties was a four-lane undivided highway. It had a narrow breakdown or acceleration lane beginning at the exit of the Deaconess property and continuing for approximately 700 feet in front of the Trust property and the next two neighboring properties before converging with the right-hand travel lane of Route 2. The portion of the Trust property adjacent to Route 2 is relatively level and is approximately eight feet above the road grade.

At some indeterminate time, Deaconess commenced construction of a senior living community on its property (The Groves). In late summer and early fall of 2007, Deaconess met with the Morrisseys about its plans to widen Route 2 to accommodate an acceleration and deceleration lane for vehicular traffic entering and exiting the Deaconess property. It presented several options for the provision of lateral support to the Trust property during the road construction. At a subsequent meeting, the Morrisseys provided Deaconess with a list of conditions as to the performance of the work and requested compensation of $50,000 to mitigate the costs of the anticipated nuisance. Deaconess ultimately decided that it would perform the road work by cutting back the existing grass escarpment and finishing the sloped surface with "riprap."4 Because this method of construction did not require an easement onto the Trust property, Deaconess informed Morrissey that he had no right to input over any aspect of the project, and that he would not be compensated for anticipated harm to the Trust property, other than possibly the transplanting of certain trees that might be affected by the road work.

On October 30, 2007, the Massachusetts Highway Department (highway department) issued a permit to Deaconess to enter on and make certain improvements to Route 2 in Lincoln.5 The permit allowed Deaconess, among other things, to widen the acceleration and deceleration lane, perform associated drainage work, install a guardrail, and construct a riprap escarpment. It also imposed limitations on construction activities and required that Deaconess indemnify the Commonwealth and the highway department against all suits, claims, or liability arising from the work covered by the permit. Delphi Construction, Inc. (Delphi), hired by Deaconess to manage construction of The Groves, commenced work on Route 2 in late November, 2007.

The Morrisseys soon complained to Delphi that a portion of the completed riprap escarpment encroached onto the Trust property, that approximately six feet of the Trust property had collapsed into the excavated but unfinished portion of the escarpment, and that a construction fence had been installed on the Trust property without permission. Their demands that the work on Route 2 stop and that they be provided with monetary compensation were ignored. On April 7, 2008, Morrissey filed an amended verified seven-count complaint for monetary damages and injunctive relief against Deaconess, the Commonwealth, and Delphi (collectively, the defendants).6 As pertinent to the present appeal, four counts were brought against the Commonwealth: interference with rights to lateral support (Count I); trespass to land (Count II); private nuisance (Count III)7; and inverse condemnation in violation of art. 10 of the Massachusetts Declaration of Rights (Count V).

On July 29, 2009, the Commonwealth filed a motion to dismiss "all claims against it" for lack of subject matter jurisdiction pursuant to Mass. R. Civ. P. 12 (b) (1), 365 Mass. 754 (1974). The Commonwealth asserted that the sole basis for Morrissey's claims was the Commonwealth's discretionary decision to issue a permit for construction on Route 2. As such, his claims were barred by the exceptions to the waiver of sovereign immunity set forth in G. L. c. 258, § 10 (b) and (e), pertaining to the performance of a discretionary function and the issuance of a permit. In his opposition to the Commonwealth's motion, Morrissey stated that subject matter jurisdiction was conferred on the Superior Court pursuant to G. L. c. 79 (eminent domain) and G. L. c. 81, § 7 (compensation for injury to real estate caused by alteration of State highway), as well as under the common law of private nuisance and constitutional principles relating to the "taking" of private property.

On October 14, 2009, a judge in the Superior Court allowed the Commonwealth's motion to dismiss as to Counts I and II, and denied the motion as to Count III.8 The judge concluded that Morrissey's private nuisance claim was not barred by the Act because G. L. c. 258 provided an unnecessary, and therefore inapplicable, remedy for a private nuisance action against a governmental entity given that decades before the enactment of the Act, "it was well established that a municipality was not immune from liability if it created or maintained a private nuisance on its land which caused injury to the real property of another." Murphy v. Chatham, 41 Mass.App.Ct. 821, 824-825 (1996), quoting Asiala v. Fitchburg, 24 Mass.App.Ct. 13, 17 (1987).

In contrast, the judge further concluded that Morrissey's claims that the Commonwealth interfered with his rights to lateral support and trespassed onto the Trust property could not survive the motion to dismiss because the Commonwealth has not waived immunity with respect to claims based on a discretionary decision, the issuance of a permit, or an alleged failure to prevent or diminish harmful consequences that it did not originally cause. See G. L. c. 258, § 10 (b), (e), and (j).9 In addition, the judge stated that, contrary to Morrissey's contention, the court did not have jurisdiction over these claims pursuant to G. L. c. 81, § 7, because the Commonwealth "did not involve itself in the alteration of Route 2 by either controlling the work allegedly performed by Deaconess or Delphi Construction, Inc. or taking any portion of the Trust Property." Instead, the judge continued, the Commonwealth's only role in the alteration of Route 2 was its decision to issue a permit to Deaconess and, because Morrissey's claims against the Commonwealth for interference with his rights to lateral support and for trespass were based on this discretionary decision, these claims were barred by the exceptions to the waiver of sovereign immunity set forth in § 10. The Commonwealth appealed,10 and we granted its application for direct appellate review.11

2. Inclusion of private nuisance in the Act. The thrust of the Commonwealth's argument is that, when consideration is given to the genesis of the Act, as well as to its purposes and provisions, it becomes evident that the tort of private nuisance is encompassed within its purview. As such, the Commonwealth continues, in the circumstances of this case, Morrissey's claim is barred by the specific exclusions to the waiver of sovereign immunity set forth in G. L. c. 258, § 10 (b) and (e). We agree.

Prior to the enactment of the Act in 1978, the Commonwealth and its municipalities were not immune from liability with respect to claims for private nuisance. See Morash & Sons v. Commonwealth, 363 Mass. 612, 616-619 (1973) (Morash) (holding that where municipalities already were liable for private nuisances, there was no logical reason why Commonwealth should not also be liable where "it creates or maintains a private nuisance which causes injury to the real property of another"). However, recognizing that sovereign immunity was a "judicially created common law concept," id. at 615, which had precluded recovery in a wide variety of cases, see id. at 620, and that piecemeal exceptions to the doctrine had been created by judges to avoid unjust results, see id. at 623, we opined in Morash, supra at 623-624, and subsequently in Whitney v. Worcester, 373 Mass. 208, 212-213 (1977) (Whitney), that the Legislature should take action to abolish the common-law doctrine of governmental immunity from tort liability. If the Legislature declined to do so within a specified time frame, then this court would abrogate the doctrine when next presented with an appropriate case.12 See Whitney, supra at 210. See also Irwin v. Commissioner of the Dep't of Youth Servs., 388 Mass. 810, 816-817 (1983).

As a consequence of this court's directive, the Legislature enacted the Act, thereby allowing plaintiffs with valid tort claims to recover damages against the Commonwealth and other public employers, subject to certain specified limitations.13 See St. 1978, c. 512, § 15. See also Wong v. University of Mass., 438 Mass. 29, 33-34 (2002) (discussing enactment of and amendments to Act); Vasys v. Metropolitan Dist. Comm'n, 387 Mass. 51, 57 (1982) (describing purposes of Act). By this statutory enactment, the Legislature sought to abolish "sovereign immunity and the crazy quilt of exceptions to sovereign immunity... which courts [had] stitched together."14 Rogers v. Metropolitan Dist. Comm'n, 18 Mass.App.Ct. 337, 338-339 (1984). A second and equally important purpose of the Act was "to preserve the stability and effectiveness of government by providing a mechanism which [would] result in payment of only those claims against governmental entities which are valid, in amounts which are reasonable and not inflated." Vasys v. Metropolitan Dist. Comm'n, supra. See Whitney, supra at 216 ("An appropriate balance should be struck between the public interest in fairness to injured persons and in promoting effective government").

As relevant herein, G. L. c. 258, § 2, provides, in pertinent part:

In essence, the Act was enacted to provide "a comprehensive and uniform regime of tort liability for public employers in the wake of our decisions" in Morash and Whitney. Lafayette Place Assocs. v. Boston Redevelopment Auth., 427 Mass. 509, 534 (1998), cert. denied, 525 U.S. 1177 (1999).

In Count III of his amended complaint, Morrissey asserted a claim against the Commonwealth for private nuisance, alleging interference with the use and enjoyment of the Trust property. See note 7, supra. "A private nuisance is actionable when a property owner creates, permits, or maintains a condition or activity on [its] property that causes a substantial and unreasonable interference with the use and enjoyment of the property of another."15 Taygeta Corp. v. Varian Assocs., 436 Mass. 217, 231 (2002), quoting Doe v. New Bedford Hous. Auth., 417 Mass. 273, 288 (1994). With the background to the enactment of the Act in mind, we turn to the specific question whether a private nuisance claim falls within the scope of G. L. c. 258. Some nine years after the Act's enactment, the Appeals Court was given the opportunity to consider this issue.

In Asiala v. Fitchburg, 24 Mass.App.Ct. 13, 14-15 (1987) (Asiala), a homeowner brought an action against the city alleging that it had created a private nuisance by negligently failing to construct and maintain a retaining wall along her property while doing road work, and that the nuisance was interfering with the reasonable and proper use of her land. The Appeals Court concluded that the city was not entitled to a directed verdict because the procedures and defenses of the Act did not apply to the homeowner's claim. See id. at 16-18. The court recognized that the Act "removed the defense of immunity in certain tort actions against the Commonwealth, municipalities and other governmental subdivisions," id. at 17, quoting Dinsky v. Framingham, 386 Mass. 801, 804 (1982), and thus provided "an effective remedy for persons injured as a result of the negligence of governmental entities in the Commonwealth." Asiala, supra, quoting Vasys v. Metropolitan Dist. Comm'n, supra at 55. However, the court stated that such a remedy was not necessary with respect to a private nuisance action against a municipality because, "[d]ecades before the enactment of the Act, it was well established that a municipality was not immune from liability if it created or maintained a private nuisance on its land which caused injury to the real property of another." Asiala, supra. "Therefore, when the Legislature abolished the doctrine of governmental immunity by enacting the Act, it was not necessary to abolish immunity with respect to private nuisance claims [because] [t]he removal of the doctrine had already been accomplished by judicial decision." Id. at 18. Accordingly, the homeowner's nuisance claim in Asiala was not barred by the fact that she had failed to comply with the notice requirements and time limitations set forth in the Act. See id. at 16, 18.

While the Appeals Court's interpretation of the common law prior to the enactment of the Act was accurate, the court did not discuss the fact that the primary purpose of the Act was to replace the common-law doctrine of governmental immunity, and its myriad judicially created exceptions, with a comprehensive statutory scheme governing the tort liability of public employers.16 See Morash, supra at 619, 623-624. In Asiala, the court stated that "[a] statute is not to be interpreted as effecting a material change in or a repeal of the common law unless the intent to do so is clearly expressed," and it concluded that nothing in the language of the Act signaled the Legislature's intent to include private nuisance actions within its scope. Asiala, supra at 18, quoting Pineo v. White, 320 Mass. 487, 491 (1946). In our view, the enabling legislation of the Act expressed such an intent. Section 18 of St. 1978, c. 512, states: "The provisions of this act shall be construed liberally for the accomplishment of the purposes thereof but shall not be construed to supersede or repeal [G. L. c. 81, § 18, and G. L. c. 84, §§ 15-25]. Any other provision of law inconsistent with any other provisions of this chapter shall not apply."17 We read this language as expressing a clear legislative intent to abolish the common-law doctrine of governmental immunity, and to replace it with a comprehensive statutory scheme that would govern the liability of public employers in tort actions, including those for private nuisance.18

Our conclusion is supported by the plain language of § 2 of the Act, which states that a public employer shall be liable for the loss of property caused not only by the "negligent" act but also by the "wrongful" act of "any public employee while acting within the scope of his office or employment." G. L. c. 258, § 2. Because the Legislature has commanded that we are to construe liberally the provisions of the Act, see St. 1978, c. 512, § 18, we conclude that a "wrongful act" would encompass a private nuisance. See Morris v. Massachusetts Maritime Academy, 409 Mass. 179, 186 (1991) (declining to accept defendants' argument that Legislature was required to make specific mention of admiralty claims in order to bring them within ambit of Act). Accordingly, Count III of Morrissey's amended complaint, alleging that the Commonwealth created a private nuisance that interfered with Morrissey's use and enjoyment of the Trust property, falls squarely within the purview of the Act.19

Morrissey urges that if private nuisance claims now are going to be considered within the purview of the Act, then this ruling should be applied prospectively. We conclude that the circumstances do not warrant an exception from the normal rule of retroactivity. See Payton v. Abbott Labs, 386 Mass. 540, 565 (1982) ("general rule is in favor of retroactive application of a change in decisional law"). See also Papadopoulos v. Target Corp., 457 Mass. 368, 384-385 (2010). In other cases where we considered whether particular tort claims were encompassed within the ambit of the Act, we did not state that our rulings should have only prospective application. See, e.g., Molinaro v. Northbridge, 419 Mass. 278, 279 (1995) (Act does not confer immunity on municipality for claims based on wanton or reckless conduct); Morris v. Massachusetts Maritime Academy, supra at 186-187 (admiralty claims were well known under statutory and common law; Act merely expanded such claims to public employers in same manner as liability imposed on private individuals); McNamara v. Honeyman, 406 Mass. 43, 46-47 (1989) (concluding, for first time, that Act immunizes public employee from gross negligence as well as ordinary negligence). As Morrissey has pointed out, since our decision in Morash, supra at 616-619, the law in Massachusetts has been clear that where the Commonwealth creates or maintains a private nuisance which causes injury to the real property of another, it is liable to the same extent as a natural person would be. The present case simply clarifies the fact that the Act is a comprehensive statutory scheme that codified the common-law principle articulated by Morrissey. Retroactive application of our decision furthers the purpose of having a consistent and clearly defined body of law, and we envision no specific hardships or inequities that would likely follow.

3. Exceptions to waiver of immunity under Act. Although the Act has abrogated the Commonwealth's immunity in tort actions in most circumstances, the Legislature has, "for reasons of public policy, chosen to preserve sovereign immunity for certain claims, irrespective of their legal sufficiency or merit, or the gravity of the injuries alleged." Smith v. Registrar of Motor Vehicles, 66 Mass.App.Ct. 31, 32 (2006). See G. L. c. 258, § 10 (a)-(j); Fortenbacher v. Commonwealth, 72 Mass.App.Ct. 82, 85-86 (2008). As relevant to the present action, the gravamen of Morrissey's amended complaint is his allegation that the Commonwealth issued a permit to Deaconess to make specified improvements to Route 2, and that this work caused noise, dust, vibrations, and other damage to the Trust property, which interfered with Morrissey's use and enjoyment of it.20 See note 7, supra. General Laws c. 258, § 10 (e), preserves governmental immunity as to "any claim based upon the issuance, denial, suspension or revocation or failure or refusal to issue, deny, suspend or revoke any permit." The language of § 10 (e) is plain and unambiguous, and it "cuts a broad swath, exempting from recovery `any claim' in a variety of named circumstances." Smith v. Registrar of Motor Vehicles, supra, quoting G. L. c. 258, § 10 (e). "If the gravamen of a plaintiff's complaint can be traced back to any one or more of the types of events or activities delineated in § 10 (e), then the action is barred." Smith v. Registrar of Motor Vehicles, supra at 33 (sovereign immunity provisions of G. L. c. 258, § 10 [e], barred lawsuit alleging that registry of motor vehicles was negligent in issuing erroneous report about status of plaintiff's vehicle registration). Here, because the actions that allegedly caused the private nuisance occurred as a result of the Commonwealth's issuance of a work permit to Deaconess, Morrissey's claim against the Commonwealth is barred by the express language of § 10 (e).

The abrogation of sovereign immunity under the Act also does not apply to "any claim based upon the exercise or performance or the failure to exercise or perform a discretionary function or duty on the part of a public employer or public employee, acting within the scope of his office or employment, whether or not the discretion involved is abused." G. L. c. 258, § 10 (b). "The discretionary function exception is narrow, `providing immunity only for discretionary conduct that involves policy making or planning.'" Greenwood v. Easton, 444 Mass. 467, 470 (2005), quoting Harry Stoller & Co. v. Lowell, 412 Mass. 139, 141 (1992). "The line of demarcation is between those functions that `rest on the exercise of judgment and discretion and represent planning and policymaking [for which there would be governmental immunity] and those functions which involve the implementation and execution of such governmental policy or planning [for which there would be no governmental immunity].'" Greenwood v. Easton, supra, quoting Harry Stoller & Co. v. Lowell, supra at 142. Here, the Commonwealth's decision to issue a permit to Deaconess was based on policy and planning considerations regarding roadway improvements to Route 2 in light of Deaconess's construction of The Groves. As such, the issuance of the permit was a discretionary function, and, therefore, was barred by § 10 (b).21 See, e.g., Barnett v. Lynn, 433 Mass. 662, 664 (2001) (immunity conferred where city's decision not to erect fence on city property to prevent sledding was based on allocation of limited resources and, as such, was discretionary function); Patrazza v. Commonwealth, 398 Mass. 464, 469-470 (1986) (immunity conferred where design of highway guardrail and policy implementing its use were encompassed within discretionary function exception of § 10 [b]); Drivas v. Barnett, 24 Mass.App.Ct. 750, 757 (1987) (immunity conferred on town where design of intersection encompassed within discretionary function exception of § 10 [b]).

4. Other claims. In his brief to this court and in a supplemental letter filed pursuant to Mass. R. A. P. 16 (1), as amended, 386 Mass. 1247 (1982), see note 8, supra, Morrissey challenges the judge's dismissal of Count I (interference with rights to lateral support), Count II (trespass to land), and Count V (inverse condemnation) of his amended complaint. However, Morrissey did not seek entry of a separate and final judgment on those claims pursuant to Mass. R. Civ. P. 54 (b), 365 Mass. 820 (1974), which, if allowed, would have enabled him to file an immediate appeal.22 In the absence of such action, no appeal can be taken from a trial judge's partial "judgment" on a claim prior to entry of a final judgment disposing of all claims against all parties to the action. See Rollins Envtl. Servs., Inc. v. Superior Court, 368 Mass. 174, 178-179 (1975) (dismissing effort by plaintiff to obtain piecemeal appellate review of interlocutory order); Bragdon v. Bradford O. Emerson, Inc., 19 Mass.App.Ct. 420, 422-423 (1985). Contrast note 10, supra. Rule 54 (b) is directed toward efficient use of judicial resources, "balancing the need for immediate review, based on the likelihood of injustice or hardship to the parties of a delay in entering a final judgment as to part of the case, against the appellate courts' `traditional abhorrence of piecemeal appellate review,' . . . as a matter of sound judicial administration." Long v. Wickett, 50 Mass.App.Ct. 380, 387 (2000), quoting Atkinson's Inc. v. Alcoholic Beverages Control Comm'n, 15 Mass.App.Ct. 325, 327 (1983). In light of our "bedrock policy against premature and piecemeal appeals," Long v. Wickett, supra at 388, the narrow exception to this policy created by rule 54 (b) is exercised sparingly. See id. at 389. We do not consider Morrissey's challenges to the dismissal of Counts I, II, and V of his amended complaint because no appeal is properly before us.

5. Conclusion. The portion of the October 14, 2009, order of the Superior Court denying the Commonwealth's motion to dismiss Count III of Morrissey's amended complaint, alleging private nuisance, is reversed. This case is remanded to the Superior Court for further proceedings in accordance with this opinion.

So ordered.