Need a drainage permit in Maryland? Here’s what you need to know:

Maryland has strict drainage permit rules that vary by county and project type. Whether you’re building a patio, adding an Accessory Dwelling Unit (ADU), or tackling a landscaping project, understanding these requirements is crucial to avoid fines, delays, or legal trouble.

Key Takeaways:

• When Permits Are Needed:
  • Land-disturbing activities over 5,000 sq. ft. or moving 100+ cubic yards of earth.
  • New construction, additions, or any project affecting stormwater runoff.
  • Hardscaping (e.g., driveways, retaining walls).
  • Modifications to storm drain systems or stormwater management.
• County-Specific Rules:
  • Montgomery County: Drainage plans required for smaller lots (<15,000 sq. ft.) and ADUs.
  • Prince George’s County: Special programs address drainage issues in new homes.
  • Baltimore City and County: Strict stormwater management plans for public infrastructure.
• Application Process:
  • Prepare site surveys, stormwater calculations, and plans signed by licensed engineers.
  • Submit required documents, including erosion control plans.
  • Review times vary (2–4 weeks per cycle depending on the county).
• Compliance and Maintenance:
  • Follow Environmental Site Design (ESD) rules to manage runoff naturally.
  • Regular inspections and maintenance are required to avoid penalties.

Pro Tip: Hire a licensed professional to streamline the process, ensure compliance, and avoid costly mistakes.

Planning a project? Read on for detailed county-specific rules, application steps, and tips to stay compliant.

MDE Guidance For Protecting Stormwater Best Management Practices During Construction November 2023

When You Need Drainage Permits in Maryland

Understanding when drainage permits are required in Maryland can save you from costly delays and potential legal troubles. Permit requirements vary depending on the county and the type of project, with specific thresholds that determine when permits are necessary. Below, we break down the key project types and location-based factors that dictate when permits are needed.

Projects That Require Permits

Land-disturbing activities are a primary trigger for drainage permits in Maryland. For instance, in Montgomery County, if a project involves disturbing more than 5,000 square feet of land or moving over 100 cubic yards of earth, a sediment control permit is required ^[8]. This applies to most major landscaping and construction efforts.

New construction and additions also come with specific requirements. In Montgomery County, drainage plans are mandatory for new single-family homes or additions on lots smaller than 15,000 square feet if no approved stormwater management plan exists ^[8]. Additionally, any new detached Accessory Dwelling Unit (ADU), regardless of its size or the lot’s dimensions, requires a drainage plan ^[8].

Hardscaping projects often need permits based on their scope. For example, in Prince George’s County, permits are required for projects such as driveways, paving, retaining walls over 2 feet high, and brick or block privacy walls exceeding 4 feet ^[6].

Storm drain system work necessitates permits when public infrastructure is involved. Montgomery County mandates a Storm Drain Permit for any enclosed storm drain system within the county’s right-of-way ^[4].

Stormwater management modifications on private property can also trigger permit requirements. In Charles County, permits are required for building stormwater conveyance systems, including pipes, inlets, gutters, ditches, swales, manholes, or junction boxes. Grading that changes how a property handles runoff also requires a permit ^[9].

Location-Based Requirements

Permit requirements can also depend on local zoning rules and the physical location of the project.

Lot size and zoning play a crucial role. Montgomery County, for instance, enforces water runoff control measures for construction on lots under 15,000 square feet if no stormwater management plan has been approved, as outlined in Chapter 8, Section 8-29B ^[8]. These rules are particularly important for smaller residential properties where drainage issues could affect neighboring homes.

Floodplain and critical areas come with stricter regulations. Prince George’s County uses a "100-Year Stormwater Management Control Map" to identify areas where enhanced stormwater controls are mandatory ^[3]. If your property falls within one of these zones, stricter permit requirements will apply regardless of your project’s size.

Municipal boundaries and proximity to public infrastructure can impose additional obligations. In Baltimore City, for example, the Department of Public Works (DPW) must approve stormwater management plans for land-disturbing activities [7]. Similarly, Baltimore County has its own set of stormwater management permit requirements ^[5], and projects that affect county roadways or rights-of-way are subject to more stringent permitting rules ^[4].

New development areas often have heightened oversight. Prince George’s County introduced the Drainage Defects Complaint Program in October 2020 to address drainage issues in newly constructed homes ^[3]. This program highlights how location-based requirements continue to evolve in response to emerging drainage challenges.

Types of Drainage Permits in Maryland

Maryland has a structured system of drainage permits aimed at managing water flow and protecting the environment. Knowing the different types of permits can help streamline the approval process and ensure all regulations are met.

Stormwater Management Permits

Stormwater Management Permits are designed to control runoff from developed areas, minimizing stream erosion and reducing pollutants in waterways ^[2]. While the Maryland Department of the Environment oversees these permits at the state level, individual counties have their own programs with specific requirements.

The process typically begins with concept approval. For instance, in Montgomery County, obtaining a Stormwater Management Concept Approval is required before securing Maryland-National Capital Park and Planning Commission (M‑NCPPC) approvals, such as preliminary and site plans. Special application categories are available for projects in Special Protection Areas (SPAs) ^[2].

Once the concept is approved, construction phase permits allow developers to implement the approved plans. In Baltimore County, a standard Stormwater Management Permit is valid for two years, providing a clear timeline for project completion ^[5]. Meanwhile, in Baltimore City, developers must submit detailed stormwater management plans to the Department of Public Works (DPW). These plans should include site delineation, identification of land disturbance types, measurements of existing impervious surfaces, development type classification, watershed identification, and calculations for stormwater management requirements [7].

This state-regulated process differs from federal and county-specific requirements, which are outlined below.

NPDES Permits

NPDES (National Pollutant Discharge Elimination System) Permits are part of a federal initiative to prevent water pollution. These permits, administered in Maryland by the Department of the Environment under EPA authority ^[11], are separate from stormwater management permits. Construction General Permits under NPDES are mandatory for sites disturbing one acre or more.

While NPDES permits focus on preventing pollutants from entering waterways, stormwater management permits deal with controlling runoff volume and flow rates. Before construction begins, an approved erosion and sediment control plan is also required to prevent sediment from washing into nearby water systems ^[10].

County-specific regulations further enhance these federal and state guidelines, as discussed next.

County-Specific Permits

Maryland’s counties have additional drainage and stormwater permit requirements tailored to regional infrastructure and environmental needs.

In Montgomery County, construction projects must comply with the County’s Drainage Design and Roadway Standards. This ensures proper installation of pipes and storm drain structures to prevent flooding and maintain safe road conditions. The review process usually takes 2–3 weeks per cycle, and all plans must be prepared, signed, and sealed by a professional engineer or licensed land surveyor in Maryland ^[4].

Prince George’s County has a comprehensive permitting system that includes building, site/road, and health permits. This system coordinates with agencies like M‑NCPPC, WSSC, and PGSCD for necessary approvals. Municipalities within the county may also impose additional requirements ^[1].

Baltimore County operates its own Stormwater Management Permit program, which includes specific application procedures ^[5].

In Charles County, permits are required for constructing stormwater conveyance systems, such as pipes, inlets, gutters, ditches, swales, manholes, or junction boxes. Grading activities that alter runoff management also require permits ^[9].

Since each county has unique challenges and infrastructure considerations, it’s important to consult the specific county’s guidelines for any additional requirements beyond state-level regulations ^[4].

How to Apply for a Drainage Permit

If you’re planning to apply for a drainage permit in Maryland, you’ll need to follow a series of steps: preparing beforehand, gathering the necessary documents, submitting your application, undergoing a review process, paying fees, and finally, receiving your permit ^[5]. By organizing everything in advance, you can make the process much smoother.

Pre-Application Preparation

Before diving into the application process, it’s crucial to get your site ready and consult with a licensed professional. In Maryland, your plans must be prepared, signed, and sealed by a professional engineer or land surveyor licensed in the state ^[4]. This rule applies statewide, including in counties like Montgomery, where storm drain and paving permits are common.

Start by conducting site surveys and hydrologic studies. These help identify any drainage issues and provide the data needed for professional engineers to create stormwater management calculations and design effective drainage solutions. Proper preparation can save you time during the review process.

In Montgomery County, you’ll need computer-generated plans at the correct scale, along with a soils report ^[4]. This report is essential for designing an accurate drainage system. Each county or municipality may have specific requirements beyond state regulations, so it’s wise to check with your local jurisdiction for any additional steps or studies.

Once your site is ready, make sure you have all the required documents in hand.

Required Documents Checklist

Document requirements can vary widely depending on the county, so it’s important to review your local jurisdiction’s checklist. For instance, Baltimore County requires Stormwater Management Plans as part of the stormwater management permit application ^[5]. Meanwhile, Prince George’s County uses both a submittal checklist and a design review checklist, which must be completed by the design professional ^[12]. This dual system ensures that nothing is overlooked.

Montgomery County allows flexibility in its application process, letting you apply for storm drain and paving permits either separately or as a combined permit ^[4]. Commonly required documents include site maps, stormwater calculations, erosion control plans, and construction drawings. If your project affects wetlands, waterways, or floodplains, you may also need additional documentation from the Maryland Department of the Environment (MDE) ^[1].

When uploading documents through online portals, be sure to follow any specified naming conventions ^[5]. Properly named files make it easier for reviewers to locate and evaluate your submissions, which could help speed up the process.

Application Review Timelines

The time it takes for your application to be reviewed depends on the county and the type of permit you’re seeking. For example, in Montgomery County, plan reviews for storm drain or paving permits typically take about 2–3 weeks per review cycle ^[4]. However, incomplete or problematic submissions may require multiple rounds of review, extending the timeline.

Stormwater management concept reviews in Montgomery County take 3–4 weeks after a mandatory 3-week public comment period, with subsequent reviews requiring an additional 2–3 weeks ^[2]. The initial review takes longer due to coordination between agencies and time for public feedback.

In Baltimore County, an online portal system allows applicants to monitor comments and track required revisions in real time ^[5]. This transparency helps applicants address feedback quickly and keep their projects on schedule.

Several factors can influence review timelines, including the complexity of the project, the quality of the submission, and the workload of the reviewing staff ^[2]. Submitting a complete and well-prepared application can significantly improve your chances of a quicker approval.

Montgomery Planning has strict deadlines: 90 days for Sketch Plans and 120 days for Preliminary and Site Plans, with limited extension options ^[13]. The Planning Director can grant a one-time 30-day extension, but further extensions require approval from the Planning Board ^[13].

In Prince George’s County, applicants must include an attestation certifying the accuracy and completeness of their submission at the time of application ^[1]. This extra step reinforces the importance of thorough preparation.

With the rise of digital systems, many counties, such as Baltimore, now offer online application processes. These systems streamline the process by allowing you to create an account, input applicant and project details, upload documents, and submit everything electronically ^[5]. This digital approach pairs well with structured document checklists, making it easier to stay organized and meet all requirements.

Key Compliance Standards and Regulations

Maryland has established a set of compliance standards aimed at protecting the environment and promoting effective stormwater management. These standards differ depending on the county and the specific type of project, offering clear guidelines for design, control, and maintenance expectations across the state.

Environmental Site Design Requirements

In Maryland, all new developments must incorporate Environmental Site Design (ESD) to the Maximum Extent Practicable (MEP). This involves mimicking natural water flow patterns, enhancing infiltration, and reducing reliance on traditional drainage systems. Montgomery County, for instance, requires enclosed storm drain systems to meet its Drainage Design Criteria guidelines^[4].

Special rules apply near airports. Within 4 miles of BWI Airport and 3.3 miles of Martin State Airport, stormwater facilities must dewater within 24 hours for one- and two-year storms, and within 48 hours for ten-year storms. Only infiltration systems, underdrains, dry wells, or underground filtering systems are allowed. Detention facilities and constructed wetlands are explicitly prohibited in these zones^[14].

Anne Arundel County implemented its Stormwater Management Regulations on November 22, 2010, with the Maryland Department of the Environment granting approval in September 2011^[15].

Erosion and Sediment Control Standards

Maryland’s erosion and sediment control program addresses issues like erosion, siltation, and flooding caused by construction activities^[10]. Projects disturbing 5,000 square feet of soil or involving the excavation of 100 cubic yards or more must have an approved erosion and sediment control plan before work begins^[10].

The 2011 Maryland Standards and Specifications for Soil Erosion and Sediment Control serves as the technical basis for these plans^[16]. In Baltimore County, compliance with these plans is closely monitored, with inspectors withholding permit approvals until all sediment control measures are installed^[17]. Preconstruction meetings must also follow the sequence outlined in the approved plan^[17].

Montgomery County takes a similar approach, requiring an Engineered Sediment Control Permit for projects meeting the same size thresholds^[18]. Violations can lead to enforcement actions such as correction notices, stop-work orders, or declarations of illegal continuance^[17].

Airport zone projects have additional requirements. Erosion and sediment control plans must include at least one dewatering device, and contractors are required to pump standing water through filtering systems to a clear water outfall within 24 hours of a storm event^[14].

Inspection and Maintenance Obligations

Owners of stormwater facilities are responsible for ensuring their systems remain functional over time^[19].

Since 1997, St. Mary’s County has operated a robust inspection program, which includes triennial reviews and field inspections of stormwater management practices^[19]. The Maryland Environmental Service oversees inspections for over 1,000 stormwater systems in the county, conducting reviews during the first year of operation and at least once every three years thereafter^[19].

To prioritize maintenance, counties use scoring systems. In St. Mary’s County, systems are rated on a 1–10 scale, with scores of 7 or below triggering follow-up inspections. For example, a score of 1 indicates a catastrophic failure with severe safety risks, while a score of 10 means the system is in perfect working condition.

Howard County has moved to digital submissions, requiring electronic submission of stormwater and drainage system data, along with floodplain-related certificates for projects near Special Flood Hazard Areas[20]. On December 20, 2024, the county submitted its 29th annual permit update to the Maryland Department of the Environment[20].

NPDES permit coverage is another critical element. St. Mary’s County has operated under the State NPDES General Discharge Permit Number 13-IM-5500 since October 31, 2018^[19]. This permit mandates regular compliance monitoring and annual reporting.

County agencies maintain detailed inspection reports to track maintenance needs. When problems are identified, counties notify owners, set repair deadlines, and conduct follow-up inspections. If repairs are not completed as required, enforcement actions may follow^[19]. Owners are encouraged to keep thorough records of all maintenance activities and act promptly on county notifications to avoid penalties.

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Common Compliance Challenges and Solutions

For property owners in Maryland, navigating drainage permit requirements can be tricky. But understanding the common challenges and their solutions can help you avoid costly mistakes and stay compliant.

Runoff and Impervious Surface Management

One of the biggest hurdles for Maryland property owners is managing water runoff from surfaces like driveways, patios, and rooftops. For example, improperly installed fences can block stormwater flow, leading to pooling and potential property damage^[3]. Similarly, issues like washouts along paved edges often stem from poor maintenance or the use of subpar materials^[22].

Here are some common runoff problems and their causes:

Redevelopment projects often come with tighter regulations, such as a 50% reduction in impervious surfaces or equivalent water quality measures^[21]. To tackle these challenges, ensure fences are designed with stormwater flow in mind, and regularly clean drainage systems like ditches and culverts^[3][22]. Reducing impervious surfaces or adding water quality management features can also help meet compliance standards^[21]. Prince George’s County even offers a Drainage Defects Complaint Program for new homes with drainage issues^[3].

But runoff isn’t the only challenge – balancing drainage needs with vegetation preservation adds another layer of complexity.

Vegetation and Tree Preservation

The Forest Conservation Act in Maryland brings its own set of challenges, especially when drainage projects involve areas near trees. Property owners must carefully plan projects to avoid damaging root systems while staying compliant with tree protection ordinances. Maryland’s ambitious goal of planting five million trees by 2031 has led to stricter rules around tree removal and replacement during construction^[24]. Since urban runoff is a major source of pollution, tree planting has become a key strategy for addressing these concerns^[24].

Reforestation rules require landscaped areas to include forests at least 35 feet wide and covering a minimum of 2,500 square feet^[25]. Additionally, the Maryland Roadside Tree Law requires permits and coordination for projects that impact trees near public rights-of-way, making it crucial to work with professionals who can integrate landscaping with drainage solutions^[23][24].

Once these design challenges are addressed, the focus shifts to long-term compliance through consistent maintenance.

Long-Term Maintenance Requirements

Staying compliant doesn’t end with obtaining a permit – it requires ongoing maintenance. Many property owners overlook the continuous obligations tied to stormwater permits, which can lead to fines or legal trouble if neglected^[26]. For instance, Stormwater Pollution Prevention Plans (SWPPPs) must be regularly updated and monitored to remain compliant^[26].

"The MS4 general permit is designed to reduce the amount of sediment and other pollutants entering state waters from stormwater systems." – Tara Ostendorf, Moore’s Environmental Team Lead^[27]

Key maintenance tasks include cleaning inlets, paved areas, and filters, as well as maintaining landscaping to prevent violations^[28]. Proper storage of materials in raised tanks or containers can help avoid leaks, while organized trash management – like keeping dumpster lids closed and preventing overflow – reduces risks^[28]. Spill cleanup protocols should include spill kits and trained personnel for immediate response^[28].

Erosion and sediment control measures, such as mulching, seeding, and slope drains, are also essential for protecting water quality and preventing violations^[28]. Regular discharge testing ensures compliance with stormwater permit limits, while routine equipment inspections can catch potential issues before they worsen^[26]. Good housekeeping practices – like clearing debris, securing trash containers, and keeping outdoor areas clean – are equally important^[26]. Record-keeping for inspections, maintenance, and corrective actions is critical, along with staying informed about changing state and federal stormwater regulations^[26].

For property owners in central Maryland, Pro Landscapes MD offers a range of drainage services, from installation and repair to stormwater management and ongoing maintenance, ensuring long-term compliance with permit standards.

Professional Services for Permit Applications

Navigating Maryland’s drainage permit requirements can feel like a maze, especially with multiple agencies and technical standards in play. Professional services can make this process far more manageable, helping to streamline applications and avoid common pitfalls.

Engineering and Design Services

In Montgomery County, storm drain and paving permits must be prepared, signed, and sealed by a licensed engineer or land surveyor to meet County design standards ^[4]. These professionals handle hydrologic calculations, design stormwater systems, and ensure compliance with environmental regulations. They also use DPIE’s review checklists to confirm that plans are accurate, reducing the chances of rejections or revisions ^[1]. When plans are certified by licensed professionals, reviewing agencies are more likely to trust their technical accuracy, which can help avoid delays during the review process.

Permit Expediting Services

The permit review process in Maryland often requires coordination with several agencies. For instance, in Prince George’s County, agencies like local health, planning, environmental, and transportation departments are typically involved ^[1]. Concept reviews for stormwater management usually take three to four weeks, following a mandatory three-week agency comment period ^[2]. However, this timeline depends on having a complete and accurate application from the start. Professional assistance ensures applications are submitted correctly, reducing the risk of abandonment ^[1]. Anne Arundel County even advises hiring a qualified professional familiar with the process to conduct site feasibility studies, which can save time and resources ^[29].

By tackling technical calculations, coordinating with multiple agencies, and ensuring compliance, these services help smooth out the challenges that often delay permit approvals.

Combined Landscaping and Drainage Solutions

Taking an integrated approach that combines permitting with construction can lead to significant time and cost savings. Pro Landscapes MD offers comprehensive drainage solutions, covering everything from design to maintenance. Their services include drainage installation, drain pipe placement, French drains, dry riverbeds, stormwater management, grading, land leveling, and yard repair. By blending drainage expertise with landscaping and hardscaping services, they deliver solutions that not only manage water effectively but also enhance outdoor spaces with features like patios, walkways, and retaining walls.

Conclusion

Navigating Maryland’s drainage permit process might seem complicated, but it becomes much more manageable when you understand local requirements and ensure that your plans are professionally prepared and sealed ^[4]. Taking these steps upfront can save time and prevent unnecessary delays.

Keep in mind that the application review process often takes several weeks, so it’s wise to plan ahead. Be prepared to make revisions based on feedback from reviewers ^[5]. Many local counties now require digital submissions, along with detailed reviews, which highlights the importance of submitting a thorough and accurate application ^[5].

For more complex projects, hiring licensed professionals is a smart move. For instance, Anne Arundel County recommends working with experts who are familiar with the process to conduct site feasibility studies. This approach not only saves time and resources but also ensures that your application meets all technical standards ^[29]. Certified professionals can help streamline the approval process and maintain the integrity of your project.

Beyond the paperwork, proper drainage management plays a critical role in protecting both your property and the environment. Following permit regulations helps reduce pollution caused by stormwater runoff and safeguards nearby waterways ^[30]. The Maryland Aviation Administration emphasizes this balance:

"The MAA’s goal is to balance the need to keep passengers safe and commerce moving with the need to be good stewards of the environment-including preventing stormwater pollution where possible." ^[30]

To ensure long-term success, implement Best Management Practices, maintain your drainage systems, and stick to the approved plans ^[30]. Whether you’re installing a simple French drain or managing a complex stormwater system, adhering to proper permitting practices helps preserve Maryland’s natural resources for future generations.

For those seeking expert guidance, Pro Landscapes MD offers end-to-end drainage solutions. From initial design to ongoing maintenance, they help Maryland property owners navigate regulatory requirements while ensuring effective water management.

FAQs

What should I avoid when applying for a drainage permit in Maryland?

When you’re applying for a drainage permit in Maryland, there are a few common pitfalls to watch out for that could cause unnecessary delays or even result in a rejection.

First, double-check that your application includes complete and accurate plans drafted by a licensed professional engineer. Incomplete or incorrect details are one of the top reasons applications get denied.

Second, don’t forget about easements if your project affects public rights-of-way or existing drainage systems. Skipping this step can lead to compliance issues with local regulations, which no one wants to deal with halfway through a project.

Finally, ensure your project follows local drainage design standards and stormwater management requirements. Overlooking these guidelines can make the review process more complicated and might force you to make expensive changes down the line. Spending extra time upfront to get everything right can save you a lot of headaches later on.

How do local regulations in Maryland counties impact the process of applying for a drainage permit?

Local Regulations in Maryland Counties

In Maryland, local regulations significantly influence how the drainage permit application process unfolds. Each county sets its own requirements and procedures, aimed at ensuring effective water management and adherence to local laws.

Take Montgomery County as an example: if you’re working on a new residential project or a major addition on a lot smaller than 15,000 square feet, a drainage plan is mandatory. Over in Baltimore County, applicants must provide a Stormwater Management Plan, which comes with a two-year validity period. Meanwhile, Prince George’s County often requires additional plans and studies to be reviewed as part of their permitting process.

To navigate this process smoothly, it’s crucial to familiarize yourself with the specific rules in your county. Doing your homework – or consulting a professional – can help ensure your project meets all local requirements and avoids unnecessary delays.

What do I need to know about maintaining a drainage system in Maryland after getting a permit?

Maintaining a drainage system in Maryland after securing a permit is crucial for keeping it functional and meeting state regulations. To stay on top of this, you’ll need to focus on annual maintenance tasks like clearing out debris, controlling vegetation growth, and ensuring drainage structures remain free from blockages. On top of that, inspections every three years are mandatory to catch and fix any potential issues.

Maryland’s Stormwater Management rules emphasize the importance of keeping stormwater systems in good working order to help reduce pollution and manage runoff effectively. This means you’ll need to document all maintenance efforts and make sure the system performs as intended to safeguard local water resources. Regular upkeep isn’t just about compliance – it can save you from expensive repairs and help preserve the value and condition of your property.

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