HB 34 Maryland House of Delegates · 2026 Regular Session

Municipalities - Open Drainage Inlets - Inventory and Improvements (Mason's Law)

HB 34 requires Maryland municipalities to install approved grating systems on all open drainage inlets (with 12-inch or larger openings) that collect stormwater. These systems must prevent large debris entry while allowing water flow and be secured to prevent removal by floodwater or tools. The law applies to both new inlets (during construction) and existing inlets, mandating full installation by June 1, 2027. It directly affects all Maryland municipalities by requiring infrastructure upgrades to improve stormwater management and safety.

Issues: ✓ Transportation

Bill status passed 3 of 5 stages cleared

Introduction

Oct 2025

Committee Review

Mar 2026

House of Delegates Passage

Mar 2026

Senate Passage

Governor

Introduced Oct 21, 2025 Last action Mar 23, 2026

Maddy AI version diff · 1 comparison

What changed between versions

First - Municipalities - Open Drainage Inlets - Required Grating Systems (Mason's Law) → Third - Municipalities - Open Drainage Inlets - Inventory and Improvements (Mason's Law) · 5 edits

MODERATE

The bill was significantly expanded from a mandate requiring municipalities to install grates on drainage inlets to a comprehensive flood management program. The new version adds a requirement for municipalities to inventory their drainage systems, introduces a multi-year funding mechanism for watershed studies, and establishes a new grant program to help local governments repair flood damage and improve infrastructure.

Scope change

The bill's scope shifted from a narrow focus on physical safety (installing grates) to a broad mandate covering system inventory, capital improvements, and financial assistance for flood recovery.

REQUIREMENT

Added a mandatory requirement for municipalities to inventory and prioritize all existing open drainage inlets before making improvements.

FISCAL

Established a new grant program allowing the Department of the Environment to provide up to 50% of non-federal funding for flood control and watershed management projects.

Created specific grant provisions for subdivisions that have incurred at least $1,000,000 in infrastructure damage from flood events occurring on or after January 1, 2009.

TIMELINE

Removed the specific deadline of June 1, 2027, for installing grates on existing inlets, replacing it with a broader, ongoing improvement framework.

ELIGIBILITY

Added eligibility criteria for grants based on whether a project involves federal funding (up to 50% grant match) or only non-federal funds (minimum 25% local match required).

Floor votes · House of Delegates Mar 8, 2026

How they voted

132–0

Passed · 10 other

Total votes 142

Mar 8, 2026

D Democratic103

95 Yea 8

92% Yea

R Republican39

37 Yea 2

94% Yea

Vote distribution

All Yea All Nay Mixed No data

Full legislative history

Actions timeline

Total actions

Key actions

Committee

Mar 23, 2026

Committee

Referred Education, Energy, and the Environment

upper

Mar 20, 2026

Lower · Passed

Third Reading Passed

lower

Mar 19, 2026

Lower · Passed

Favorable with Amendments {

lower

Mar 19, 2026

Lower · Passed

Favorable with Amendments Report by Environment and Transportation

lower

Mar 8, 2026

House Of Delegates · Passed

House of Delegates Vote: pass (132-0-10)

house of delegates

Jan 14, 2026

Committee

First Reading Environment and Transportation

lower

Oct 21, 2025

Introduced

Pre-filed

lower

16 primary · 0 co-sponsors