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Stormwater Facility Maintenance & Inspection

The Stormwater Facility Maintenance Program is responsible for inspecting and ensuring maintenance of all public and private stormwater management facilities within Montgomery County. It is vital that the structures be maintained in working order so they function as intended, providing protection and stormwater management for our parks, schools, and businesses. The program is paid for by the  Water Quality Protection Charge .

What are Stormwater Management Facilities?

Stormwater facilities have two functions:

  • They absorb or slow stormwater runoff from urban surfaces such as roads, parking lots, and rooftops. 

  • They remove contaminants from the runoff.

Stormwater facilities help to slow the stormwater down and clean it before it is allowed to discharge into local streams, which helps to safeguard our waterways. They are vital infrastructure in the urban environment. The State of Maryland regulates the management of stormwater facilities to prevent stormwater pollution in our waterways.

Image of DEP staff maintaining a tree box.
DEP staff maintaining a Green Street tree box.

Inspection and Maintenance

Stormwater facilities can become clogged by trash, debris, sediment and mud, or other stormwater pollutants. The facilities themselves can develop structural cracks and leaks over time and need regular maintenance to prevent problems. When this valuable infrastructure functions well, stormwater management can:

  • Reduce flooding in our urban environment

  • Remove pollution carried by stormwater

  • Recharge the groundwater supply

  • Protect local stream banks from erosion

  • Protect public health

The Stormwater Facility Maintenance Program inspects stormwater facilities at least every three years.  There are more than 7,000 stormwater facilities in the County that require inspection.

The inspection is used to determine a facility's condition and to identify its need for maintenance. Without proper inspections and maintenance, we would not know when a facility has failed. Once a facility fails, the cost of repairs are expensive and can result in property damage or other loss. Providing routine maintenance and inspections can keep the stormwater facilities working as intended, save money, property, and protect public safety.

Who Has Responsibility for Maintenance?

Type of Facility Maintenance Responsibility

Residential stormwater facility

Structural maintenance: DEP's Stormwater Facility Maintenance Program works with citizens to assume responsibility for structural maintenance for residential stormwater facilities if the property owner has completed the  maintenance transfer process. Once the facility has completed the transfer process, DEP will assume responsibility for the structural maintenance and the owner will continue to provide non-structural maintenance to their facility. 

Nonstructural maintenance: For all facilities, nonstructural maintenance is the responsibility of the owner. This maintenance includes grass cutting, trash removal, and landscaping.

Nonresidential stormwater facility

(e.g., commercial facilities)

Maintenance for most nonresidential facilities is the responsibility of the owner. 

Local government stormwater facility

Montgomery County assumes responsibility for Structural maintenance and either assumes all, or shares responsibility for Non-Structural maintenance with the owner. (e.g. parks, schools, and libraries)

Who can Maintain Stormwater Facilities?

All stormwater facility maintenance contractors working in Montgomery County are required to have a Certificate of Attendance from the Department of Environmental Protection's Stormwater Facility Maintenance Contractor Training. Once contractors have been certified, they will be placed on a list of contractors approved by the County for maintenance of stormwater facilities.

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Where are the County's Stormwater Facilities?

The interactive map below shows all of the County's stormwater facilities. The colored dots represent different types of stormwater facilities. Clicking on a dot will reveal that particular facilities type. Look for your property on the map!

View Larger Map

Facility Maintenance Fact Sheets

Looking for help and tips on how to maintain your stormwater facility?  Find and download the appropriate maintenance fact sheet for your property!


Environmental Site Design/ Low Impact Development (ESD/LID) practices are smaller practices meant to capture the stormwater runoff from roofs, driveways, and parking lots on the same property. Overall maintenance is routine landscaping and removing tree debris and trash.

Rain Garden, Bioswale and Micro-Bioretention 

Image of the front cover of the rain garden and bioswale maintenance fact sheet.

( PDF, 255KB)

Want more information on rain gardens?

Caring for your Vegetated Stormwater Facility

Image of the front cover of the vegetated stormwater facility guide.

( PDF , 335KB)

Grass Drainage Swale

Image of the front cover of the grass swale maintenance fact sheet.

( PDF, 375KB)
Want more information on grass swales?

Buried Dry Well

Image of the front cover of the buried dry well maintenance fact sheet.

( PDF, 375KB)
Want more information on buried dry wells?

Porous Pavement

Image of the porous pavement maintenance fact sheet.

 ( PDF, 379KB)
Want more information on porous pavement?

Green Roof

Image of the front of the green roof maintenance fact sheet.

( PDF, 483KB)
Want more information on green roofs?

Infiltration Areas

Image of the infiltration area maintenance fact sheet.

( PDF, 357KB)
Want more information on infiltration areas?

Rain Barrels

Image of the front cover of the rain barrel maintenance fact sheet.

( PDF, 335KB)
Want more information on rain barrels?

Non-Structural Drainage

Image of the Non-Structural maintenance fact sheet.

(PDF, 481KB)

Green Streets

Image of the green streets maintenance fact sheet.

(PDF, 372KB)

Stormwater Ponds can have both structural and non-structural maintenance.  Learn more about stormwater ponds.

Ponds: Non-Structural Maintenance 

Image of the front cover of the Pond Non-structural Maintenance Fact Sheet

( PDF, 1.54MB)
Fact sheet applies to all property owners

Ponds: Structural Maintenance 

Front cover of the Pond Structural Maintenance Fact Sheet

( PDF, 1.07MB)
Fact sheet applies to nearly all commercial owners, and to residential owners that have not transferred their structural maintenance to the County.

Ponds: Planting Guidance 

Pond Guidance

( PDF, 2.78MB)
Fact sheet applies to all property owners.

Sand Filters or Infiltration Trenches can have both structural and non-structural maintenance. Learn more about Sand Filters and Infiltration Trenches.

Surface Sand Filters & Infiltration Trenches

Image of the front cover of the Surface Sand Filter and Infiltration Trench Maintenance Fact Sheet

( PDF, 371KB)
Fact sheet applies to all property owners

Surface Sand Filters 

Image of the front cover of the Surface Sand Filter Structural Maintenance Fact Sheet

( PDF, 365KB)
Fact sheet applies to nearly all commercial owners & to residential owners that have not transferred their structural maintenance to the County.

Infiltration Trenches

Image of the front cover of the Infiltration Trench Structural Maintenance Fact Sheet

( PDF, 509KB)
Fact sheet applies to nearly all commercial owners and to residential owners that have not transferred their structural maintenance to the County.

Belowground Stormwater Facility maintenance fact sheets describe typical structural maintenance, such as power-washing, removing sediment and debris, and replacing filters. 

Underground Storage Structures

Image of the Front Cover of the Underground Storage Structure Fact Sheet

( PDF, 346KB)

Underground Sand Filters

Image of the Front Cover of the Underground Sand Filter Fact Sheet

( PDF, 448KB)

Underground Flow Splitters

Image of the Front Cover of the Underground Flow Splitter Fact Sheet

( PDF, 450KB)
Want more information on flow splitters?

Proprietary Underground Filtering Facilities

Image of the front of the Underground Filtering Facilities Fact Sheet

( PDF, 407KB)
Including: Aqua-Filter, Bay Filter, Storm-Filter, etc.

Underground Hydrodynamic Separators 

Image of the Front Cover of the Underground Hydrodynamic Separators Fact Shee

( PDF, 332KB)
Including: Oil and Grit Separators, Baysavers, Aqua-Swirl, Stormceptor, etc.
Want more information on hydrodynamic separators?


As part of a new campaign to educate County residents about stormwater managment, DEP has installed hundreds of signs that explain how stormwater management facilities work. The signs have detailed graphics on the structure of facilities as well as information on why they are so important. If you require a higher resolution of a sign featured below, make the request to .

Bioretention Gardens

Image of the Bioretention Garden Sign

( PDF, 453KB)

Green Roof

Green Roofs Sign

( PDF, 336KB)

Infiltration Trenches

Image of the Infiltration Trench Sign

( PDF, 373KB)

Porous Pavement

Image of the Porous Pavement Sign

( PDF, 380KB)

Rain Barrels

Image of the Rain Barrels Sign

( PDF, 423KB)

Rain Gardens

Image of the Rain Garden Sign

( PDF , 491KB)

Sand Filters

Image of the sand filters sign

( PDF , 333KB)

Tree Boxes

Image of the Tree Box Sign

( PDF , 380KB)

Wet Ponds

Image of the Wet Pond Sign

( PDF , 351KB)

The Story of Stormwater

Image of the Wet Pond Sign

( PDF , 492KB)

Easements, Right of Entry, and Maintenance Agreements

A property owner of any stormwater management system is required to have an easement or right of entry and a maintenance agreement with the County for all stormwater management systems on their property.

  • The Easement and Right of Entry Documents are legal documents that describe the area the county is permitted to enter for inspection and maintenance.

  • The Covenant, also known as the maintenance agreement, is a legal document that describes who is responsible for maintenance.

The table below provides links to blank easement, right of entry and covenant documents. Developers and property owners should use these documents when creating new easements, rights of entry, and covenants for their stormwater facilities. The templates are used on all stormwater facilities throughout the County and should not be modified. There are specific documents for residential and non-residential properties.

Residential, Non-Residential, and Commercial
Property Easements and Maintenance Agreements
HOA, Townhouse, Condominium Community, Multifamily Residential, and Apartment common-owned areas.

Easement Document  (.doc, 50KB)

Covenant Document  (.doc, 48KB)

For environmental site design (ESD) on single family home and town home private property.

Grant of Stormwater Right of Entry and Maintenance Agreement ROE-SFR  (.doc, 139KB)
Non-residential and commercial properties Easement Document  (.doc, 52KB) Covenant Document  (.doc, 48KB)
Green roofs ONLY; Residential and Non-Residential Commercial Properties Easement Document  (.doc, 43KB) Covenant Document  (.doc, 39KB)

Because easements, rights of entry, and covenants are legally binding documents, all property owners of stormwater management systems should keep copies of the documents related to their property. Developers should provide these documents to the property management company or HOA after transferring ownership.

If you need to obtain a copy of the recorded stormwater covenant or easement for your property, please visit the Montgomery County Circuit Court Land Records Department  or search online at the Maryland Land Records

Maintenance Transfer Program

If you own a stormwater facility and would like to transfer it into the County's Stormwater Facility Maintenance Program, use the guidance outlined here. Residential and select non-residential facilities are eligible for transfer into the County's maintenance program.

The transfer process has three stages:

  • Stage 1: Gather Documents and Contact DEP
    Gather information to prepare the application.
  • Stage 2: Submit Application
    Submit the completed application and required documents for DEP and County Attorney review.
  • Stage 3: Record Documents
    Finalize the transfer by recording the documents and obtaining a certified copy.

Once you have completed these stages, the County becomes responsible for structural maintenance of the facility, such as leaks, stone replacement or replacing concrete and pipes. You (the property owner) however, remain the owner of the facility and continue to be responsible for non-structural maintenance around the facility, such as trash removal, grass cutting, and landscaping.

DEP highly recommends that you contact the Department before you submit your transfer paperwork to ensure that all the necessary documents have been prepared and to learn more about the transfer process. 

NOTE: Although DEP encourages homeowners' associations to submit transfer documents as soon as possible, transfer documents will not be forwarded to the County Administrative Officer until the facility has an approved final inspection and the facility is in as-built condition. However, DEP review of the transfer documents  can occur concurrently with repair work to bring the facility to as-built condition.

Stage 1: Gather Documents and Contact DEP

A variety of documentation is required for the transfer. This documentation helps to ensure that you are the verified owner and that the former owner (in many cases the developer) transferred the common area property, such as the stormwater facility, as required. The documents required include:

  • Stormwater easement and covenants
  • Information on the stormwater facility
  • Information on property location

Use the following outline as a guide for gathering the appropriate information for the application:

  1. List the number and types of stormwater facilities the property has (excluding drains) and the numbers of the property parcel(s) (tax account number(s)) on which the facilities are located.
    • Much of this information can be found on the maintenance/inspection letters provided by DEP annually or every 3 years.
    • If unknown, contact DEP for the stormwater facility numbers (each stormwater facility has a number, which is separate from the property parcel number).
    • Note that storm drains are not part of the Stormwater Facility Maintenance Program and may not be transferred.
  1. Provide a deed for the property.
    • Was the property transferred from the developer to the homeowners's association? A deed will determine whether the developer transferred the common property. A copy of the original deed that shows transfer of the parcel from the developer to the property owner is a vital document.
  1. Provide the appropriate easements and covenants for the stormwater facility or facilities. The easement defines the boundaries within which DEP will have legal authority to access the property to inspect and structurally maintain the facility. The covenant defines the stormwater responsibilities of the homeowners' association and DEP.
    • If your facility has an existing "Grant of Stormwater Management Easement and Right-of-Way" and "Declaration of Covenants Inspection/Maintenance of Stormwater Management Facility," complete the  Amendment of Declaration of Covenants  (.doc, 37KB) and attach the text description of the easement area (metes and bounds) as Exhibit A, the graphic depiction of the easement area as Exhibit B, and the original Declaration of Covenant as Exhibit C.
    • If your facility does not have an existing stormwater easement or covenant, complete the  Grant of Stormwater Management Easement (.doc, 74KB) and the  Declaration of Covenant (.doc, 72KB) documents. If requested, DEP can help provide the required easement metes and bounds (Exhibit A to the easement) and graphic depiction (Exhibit B to the easement) for the facility. The new Declaration of Covenant will be Exhibit C to the easement. Please be sure to request this service in a written letter when submitting your application documents to DEP. If you are a Condominium owner, please contact DEP prior to submitting your application because additional documents are required with your application.
    • Consider hiring an attorney. DEP suggests that property owners hire an attorney to assist in researching and preparing documents to complete the transfer process. An attorney can be especially helpful if the deed can't be located.
  1. Provide your most recent tax bill.

Do You Need Help?

DEP is happy to assist you with this process. Please email us at  or call 311 and provide the location of the stormwater facility. DEP can provide the structure type, the facility number, and insight into what to expect during the transfer process.

Stage 2: Submit Application to DEP

Once most or all of the information described under Stage 1 has been collected, fill out the  Stormwater Facility Maintenance Transfer Application form Instructions for filling out the form  are available. You must  complete, sign, and notarize all the appropriate transaction documents, such as grants of easement, declaration of covenants, or covenant amendments. Submit the application form and supporting documents for legal review by DEP and the Montgomery County Office of the County Attorney.

After legal review and certification, the County Attorney returns the documents to DEP for submission to the County Administrative Officer. After the County Administrative Officer has signed the documents, DEP returns the fully executed documents to you so they can be recorded in the land records (see below).

Stage 3: Record Documents

Once DEP returns the fully executed documents to you, the transfer process is almost finished. All that remains is for the signed documents to be recorded at  County Land Records . You must record the document with County Land Records and receive a certified copy.  Be sure to record only documents that have been signed and approved by the County. You can obtain a certified copy of a recorded document by taking a document that has been numbered and indexed to Room 219 of the Judicial Center at 50 Maryland Avenue in Rockville, Maryland.

The official approval letter will not be sent out until you obtain a certified copy of the recorded documents from County Land Records and submit the copy to DEP. Once DEP receives the certified copy of the recorded documents, Montgomery County becomes the only entity responsible for structural maintenance of the stormwater facility.

The time needed to complete the full transfer process varies depending on:

  1. Whether the application was completed correctly and, if not, how quickly corrections were submitted to DEP
  2. Whether you signed and notarized the application as requested and provided a copy of the deed, property tax bill, easement information, and amended covenant or new covenant
  3. The number of transfer applications currently being processed

Before submitting your application to DEP, contact us at  or call 311 to confirm that you have all the information you need to submit an application.

Contractor Resources

DEP's Stormwater Facility Maintenance Program relies on skilled and knowledgeable contractors to perform maintenance on stormwater management facilities. A company that performs maintenance on a stormwater management facility must hold a certificate of attendance from an approved training program. DEP offers a list of all the companies that have completed the required training.

List of contractors approved by the County for maintenance of aboveground structures to inlcude LID/ESD ( PDF, 124KB)

List of contractors approved by the County for maintenance of underground structures  ( PDF, 50KB)

How Can My Company Become Certified To Perform Maintenance in Montgomery County?

Montgomery County regulations require that a company that performs repair or maintenance on a stormwater management facility must:

  • Have demonstrated experience in stormwater management facility construction and/or maintenance
  • Have demonstrated experience in stormwater management facility inspection
  • Hold a Certificate of Attendance awarded through a trainin g program approved by DEP
    DEP offers two trainings a year. It is not a program or multiple classes. Interested contractors must take the  inter im certification test , and then plan to attend the annual Stormwater Facility Maintenance Contractor Training class.

A company that performs repair or maintenance on an  underground stormwater facility must also have the training and credentials required under applicable state and federal law, including an Oil Operations Permit from the Maryland Department of the Environment and a Confined Space Certification from the federal Occupational Safety and Health Administration (OSHA).

DEP Stormwater Facility Maintenance Contractor Training

A company interested in obtaining a Certification of Attendance for stormwater facility maintenance training must:

  • Attend the approved DEP training program OR
  • Pass the Interim Certification Test and attend the training within one year.
  • Re-certify every 3 years by attending the training

Scheduled Training Sessions

The DEP training program is usually held twice a year in the spring and winter. Email DEP to request email notification of upcoming training events. In the subject line, type "Send me dates of contractor training for Stormwater Facility Maintenance Program."

DEP Training Materials

The following documents provide the information you will need to learn to pass the  Interim Certification Test .

Interim Certification Test

Successful completion of the Interim Certification Test (minimum score of 70 percent) will allow your company to maintain and repair stormwater management facilities in Montgomery County, Maryland. To maintain your Certification of Attendance, however, it is necessary that supervisory representatives of your company attend the next Stormwater Facility Maintenance Contractor Training class.

Before being allowed to maintain stormwater facilities in Montgomery County, you will have to take this interim test and attend a training, OR attend a training in person.

Download a copy of the  Interim Certification Test ( PDF, 107MB)

Once you have completed this test, please return it to:

Montgomery County Department of Protection
Stormwater Facility Maintenance Program
255 Rockville Pike, Suite 120
Rockville, Maryland 20850
ATTN: Audra Lew

Problems and Concerns

If you have a problem with a stormwater facility, such as odor, standing water, or trash and debris, contact DEP at 311 or submit an  online complaint form .  Your questions can also be emailed to .


Stormwater facilities that are functioning as they were designed will not cause mosquito problems. Most facilities, except wet ponds, are designed to drain within 72 hours. DEP has developed a webpage and brochure with all the information you need to identify if mosquitoes are coming from a mal-functioning stormwater management facility and how to prevent these issues. The webpage also contains general information on mosquito biology and prevention.

Visit the DEP Mosquitoes webpage

Image of a DEP staff member cleaning around a storm drain.
Trash, leaves and other debris around storm drains is a common cause of flooding and water issues.

Storm Drain Problems

If you believe a storm drain is not operating effectively, you may call the  Division of Highway Services (DHS) at 311. DHS addresses issues such as blocked storm drains along roads.

Stormwater Ponds

Questions about stormwater ponds?  Visit the stormwater ponds page to learn about maintaining ponds and pond signage.