Drowning in place: local government costs and liabilities for flooding due to sea-level rise.

• Author: Ruppert, Thomas
• Position: Florida

Many areas of Florida are experiencing increased tidal flooding due to sea-level rise (SLR). Florida has experienced eight to nine inches of SLR over the past 100 years. (1) The roughly four and one-half inches of rise in the last 50 years has decreased the efficiency of some older stormwater systems designed to function with lower sea levels. As a result, tidal waters back up within the drainage systems and stormwater systems drain slower, causing more frequent flooding. Tens of billions of dollars of real estate in Florida are potentially at risk due to SLR and its commensurate flooding. (2)

How should local governments respond? Miami Beach, which has become infamous for tidal flooding, is incorporating sea-level rise into plans for spending more than $200 million to expand the city's drainage system. (3) But costs for addressing flooding will only rise with the waters, potentially drowning local governments in rising debt if not rising water. This raises the question as to whether local governments must prevent flooding due to SLR at any cost. Do local governments have a duty to perform this type of protective upgrade on outmoded drainage and flood controls or is this government action discretionary? As SLR-induced flooding causes greater inconvenience and even damage to property, will municipalities be faced with the difficult choice between expending millions of taxpayer dollars for these improvements or being subject to lawsuits from private property owners seeking damages?

Generally, claims for damages to property have been brought against local governments under both tort and constitutional taking theories. This article examines Florida jurisprudence in both since each has proven to be somewhat unpredictable, providing no definitive answer to the question of who shoulders the liability for SLR-related flooding. The article then discusses the responsibilities of local governments for drainage and applies relevant precedent to determine potential liability. Where important legal liability questions have not been squarely addressed in the realm of drainage, this article draws analogies and inferences from law developed around other types of infrastructure, such as roadways.

Flooding Damage: Tort Claims

In 1973, Florida waived sovereign immunity in tort actions with passage of Florida's torts claim act. (4) This opened the door to flooding damage cases by private citizens against local governments. Tort claims involving municipal infrastructure or services, however, may still be subject to sovereign immunity despite this statutory waiver. The Florida Supreme Court has held that despite the passage of the torts claim act, certain "discretionary" governmental functions remain immune from tort liability because such "planning" level functions of coordinate branches of government may not be subjected to scrutiny by judge or jury as to the wisdom of their performance. (5) Such planning-level functions contrast with "operational" levels of government decisionmaking.

Duties Regarding Drainage

A tort claim cannot proceed unless the defendant owed a duty to the plaintiff. However, local governments in Florida have no general duty to provide drainage. Statutes grant many powers that allow local governments to engage in the construction and management of drainage, but these are discretionary duties. (6) The Florida Supreme Court has established, however, that once a government entity has undertaken to provide protection from flood damage through the construction of a storm sewer pump or other similar system, it assumes the duty to do so with reasonable care. (7) When a local government provides this type of infrastructure, it "thereby assume[s] the duty to maintain and operate the system so that it [will] properly drain off expected excess water and prevent flooding." (8) In the face of SLR and more frequent tidal flooding, this seemingly straightforward duty raises significant questions. As many of Florida's drainage systems were designed before reliable climate change or SLR data was available, it remains unclear what type of government action is presently encompassed by the duty to maintain existing stormwater systems.

Sea-level Rise and Drainage--Duty or Discretion?

SLR impacts stormwater systems through three mechanisms that cause flooding. First, a higher sea level may cause high tides to back up through the stormwater system, causing flooding in the very areas in which the system is to drain. Second, SLR may not directly flood the land but it may cause previously dry drainage infrastructure to fill with saltwater, meaning that the affected volume of stormwater infrastructure is not available for the immediate storage or stormwater. A third related, and less appreciated, impact is that higher sea levels can cause a system to drain at increasingly slower rates. The system drains less efficiently because elevated sea levels reduce the vertical drop in the stormwater system, reducing the speed at which wafer travels through the system. Under this scenario, a rainstorm that would not have flooded an area a few decades ago may now flood the same area even if the stormwater system has been properly "maintained" to function as it was designed.

This leads us to ask the (literally multi-) million dollar question: When, due to sea-level rise, a stormwater system is...