In this section the following words have the meanings indicated. “Approved grating system” means a cover placed over the opening of an open drainage inlet in order to allow stormwater runoff to enter the drainage inlet while preventing large debris from entering the drainage inlet. “Approved grating system” includes: a standard yard inlet; a raised grate yard inlet; a trash rack grating, provided that the rack has at least four sides, each of which is at least as large as the diameter of the surface opening; and for new drainage inlets, a precast concrete box incorporated into the construction of the drainage inlet. “Open drainage inlet” means a structure with a surface opening that: has a diameter of 12 inches or more; and is designed to collect and drain stormwater runoff. “Open drainage inlet” includes an open headwall structure attached to a culvert. “Open drainage inlet” does not include: a grate inlet; a curb inlet; a combination curb and grate inlet; a surface–level drainage tunnel with only one surface–level inlet and one direct surface–level outlet; a slotted inlet; or a culvert located on an open drainage highway. “Privately owned existing open drainage inlet” means an inlet that is located on private property and was installed before October 1, 2026. “Publicly owned existing open drainage inlet” means an inlet owned and maintained by the municipality that was installed before October 1, 2026. “Publicly owned existing open drainage inlet” does not include inlets: owned or maintained by a federal entity, State entity, county, or school board; or inspected by the Department of the Environment. A municipality may enter private property to: complete the inventory required under subsection (c) of this section; and install an approved grating system. On or before July 1, 2027, a municipality shall inventory the number and location of all publicly owned existing open drainage inlets and privately owned existing open drainage inlets in the municipality. On or before April 1, 2028, a municipality shall develop a prioritization plan for making improvements to publicly owned existing open drainage inlets and privately owned existing open drainage inlets. The plan shall prioritize making improvements to publicly owned existing open drainage inlets and privately owned existing open drainage inlets that pose the greatest risk to public safety. A municipality is not required to make improvements to publicly owned existing open drainage inlets and privately owned existing open drainage inlets that do not pose a legitimate risk to public safety. A municipality shall include in the plan an explanation of the reason for each publicly owned existing open drainage inlet and privately owned existing open drainage inlet excluded from the prioritization plan. Improvements may include: installation of an approved grating system secured to the inlet end of the open drainage inlet or the concrete structure built to house the drainage inlet, in a manner that prevents the approved grating system from being removed without the appropriate tools or by the force of flood water; or installation of fencing that: obstructs at least 50% of any opening; and is designed and installed in a manner that would not allow a person to enter the open drainage inlet. On or before April 1, 2028, each municipality shall notify a private property owner with a privately owned existing open drainage inlet that the installation of an approved grating system or fencing is required in accordance with paragraph (2) of this subsection. On or before April 1, 2031, each municipality shall make improvements to all publicly owned existing open drainage inlets and privately owned existing open drainage inlets included in the prioritization plan developed under paragraph (2) of this subsection. A municipality is responsible for the cost of installing improvements on all publicly owned existing open drainage inlets and privately owned existing open drainage inlets. A municipality may apply to the comprehensive flood management grant program within the Department of the Environment to cost–share a portion of the installation costs. A municipality is not required to add improvements to any publicly owned existing open drainage inlets and privately owned existing open drainage inlets if it would significantly impair the hydraulic capacity of the drainage system. Once a municipality has installed an approved grating system on a privately owned existing open drainage inlet, the municipality: is not responsible for maintaining improvements installed on a privately owned existing open drainage inlet; and may not be held liable for incidents arising out of the maintenance of an approved grating system. Any new open drainage inlet installed in a municipality shall be equipped with an approved grating system that meets the requirements for installation described in this section.