“Tort claims against a California government entity may proceed only if authorized by the California Government Claims Act. This principle applies to claims based on a public employee’s acts or omissions and to claims based on “defective conditions” of public property. Broadly, the Act abolishes all public entity common law tort liability. State and local public entities may be liable for personal injury and wrongful death only if a statute expressly so authorizes. Although several sections of the Act provide for government entity liability under specified conditions, many sections also grant public entities and/or their employees broad immunity from liability. And, in any event, any liability authorized by the Act is subject to ordinary common law defenses, such as comparative negligence and assumption of the risk. Governmental immunity is an affirmative defense that must be raised by defendant. As such, the defense may be deemed waived or forfeited if not timely asserted.
No public employee (and thus, absent an overriding statute, no public entity) is liable for injuries resulting from discretionary acts within the scope of employment—even if that discretion is abused. Where a governmental “enactment” subjects a public entity to a mandatory (not simply a discretionary) duty designed to protect against the risk of a particular kind of injury, the entity is liable for an injury of that kind legally caused by its failure to discharge the duty unless the entity “establishes that it exercised reasonable diligence to discharge the duty.
Gov.C. § 835 sets out the exclusive conditions under which a public entity may be held directly liable for injuries caused by a “dangerous condition” of public property. A public entity may be held liable only if all of these conditions are satisfied: The condition must be one that creates a substantial risk of injury when the property or adjacent property is used with due care in a reasonably foreseeable manner (Gov.C. § 830(a)); The condition must have existed at the time of the injury; The injury must have been “proximately caused” by the condition; The condition must have created a “reasonably foreseeable” risk of the kind of injury suffered; and Either (a) the condition must have been created by a negligent or wrongful act or omission of an employee within the scope of his or her public employment, or (b) the entity must have had “actual or constructive notice” of the condition (see Gov.C. § 835.2.) sufficiently before the injury to have taken measures to protect against the risk involved (either by repairing the condition, providing safeguards against the risks, or warning of the potential harm). Ordinarily, these are fact questions. However, courts may conclude as a matter of law that a condition is not dangerous if no reasonable person would consider it posed a substantial risk of injury when the property is used with due care in a reasonably foreseeable manner.
Subject to several exceptions, public entities are immune from liability for injuries to any person who ‘participates in a hazardous recreational activity, including any person who assists the participant, or to any spectator who knew or reasonably should have known that the hazardous recreational activity created a substantial risk of injury to himself or herself and was voluntarily in the place of risk, or having the ability to do so failed to leave …’
[California Practice Guide: Personal Injury [certain citations omitted]]