What is ESD and when does it apply?

Environmental Site Design uses small-scale practices to mimic natural hydrology. It is required for new development and substantial redevelopment statewide under Environment 4-203.

Do counties enforce stormwater rules locally?

Yes. Each Maryland county and municipality administers stormwater plans under MDE oversight. Local ordinances must meet or exceed state standards in the Stormwater Design Manual.

Maryland Stormwater Management (2026)

Key Facts

Statute: Environment 4-201 et seq.
Design Standard: ESD to MEP
Manual: MD Stormwater Design Manual
Permit: MS4 NPDES
Penalty: Up to $25,000/day

Source: Maryland General Assembly

Full Breakdown

Maryland Environment Article Title 4 Subtitle 2 requires every county and municipality to adopt stormwater ordinances meeting Maryland Department of the Environment minimum standards. Developers must implement Environmental Site Design (ESD) to the maximum extent practicable, treating runoff to recreate pre-development hydrology. The 2000 Maryland Stormwater Design Manual (updated periodically) prescribes practices like micro-bioretention, rain gardens, and permeable pavement. Phase II MS4 permits administered by MDE govern municipal separate storm sewer systems. Enforcement includes stop-work orders, restoration requirements, and penalties up to $25,000 per day.

Violations & Penalties

Stormwater violations may incur civil penalties up to $25,000 per day, criminal misdemeanor charges, mandatory restoration, and stop-work orders.

Maryland Stormwater Management Act Statewide Standards

Key Facts

Full Breakdown

Violations & Penalties

Frequently Asked Questions

Sources

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