Underground Stormwater Detention Facilities

Those of us who live in cities often don’t consider how stormwater runoff is handled because we don’t see the detention facilities that control it. In non-urban areas, vegetated surfaces are the natural diverters of storm runoff. In areas that have been urbanized with paving and buildings, there is significant danger associated with stormwater runoff that has nowhere to go. It can damage waterways, accelerate erosion, and destroy aquatic habitats if left unchecked.

iSTORMWATER has the expertise required to provide all necessary commercial stormwater services related to underground stormwater detention facilities. Call us at (443) 699-2828 or contact us online to see how we can serve you.

What Is an Underground Stormwater Detention Facility?

Underground stormwater detention facilities are structures that allow control over water runoff from developed sites. Most people don’t realize that when they are walking across a parking lot or other solid surface, there may be an underground detention facility right below their feet. These underground facilities are a smart option when there is not enough space to establish an aboveground detention facility.

Underground detention facilities are primarily designed to manage the amount of runoff resulting from a storm. They delay or stagger the movement of water downstream to minimize the occurrence of flooding and the associated erosion. In some cases, underground stormwater structures are attached to filter banks, helping to capture sediment, oil, chemicals, and a variety of other pollutants before they contaminate nearby streams and rivers.

iSTORMWATER can provide the maintenance your underground stormwater detention facility needs to remain functional and efficient. Give us a call at (443) 699-2828, or reach us online to learn more about our maintenance services.

Benefits of Regular Maintenance for Underground Detention Facilities

Belowground stormwater systems come in such a wide array of materials and configurations that there is no standard protocol that fits them all. The manufacturers of these facilities usually create their own schedule for recommended inspections and maintenance, which must be followed to maintain regulatory compliance. Annual maintenance is usually the minimum requirement for larger systems, while smaller systems typically need cleaning multiple times per year. Aside from compliance, the benefits of maintenance for underground stormwater detention facilities include:

  • Ensuring the structure is performing as intended
  • Ensuring the low-flow orifice is clean and unobstructed
  • Keeping filters clear
  • Detecting structural aberrances
  • Detecting the need for repairs


The iSTORMWATER team has more than 20 years of experience in stormwater management, making us Washington, DC’s premier partner for underground detention facility maintenance. We work with the most skilled technicians and strive for satisfaction in every job we do.

Choose iSTORMWATER for proven stormwater service in DC, Northern Virginia, and Southern Maryland. Call (443) 699-2828 to speak to our team or contact us online for more information.

Frequently Asked Questions

What should I inspect during an inspection of an underground stormwater detention facility?

During an inspection from iSTORMWATER, we measure sediment accumulation with a stadia rod, measure oil and hydrocarbons with a Teflon bailer, and dip out floating solids as needed. When cleaning is required, we use a sump-vacuum truck to remove captured sediment and floatables. We also replace filters and absorbent media once they reach capacity. We’ll provide you with a maintenance and activity report, complete with photo documentation and a list of the services we performed for your records.

How often does an underground stormwater detention facility need maintenance?

Many stormwater facility manufacturers provide a recommended inspection and maintenance schedule that must be carried out for compliance purposes. Property owners should expect to give extra attention to their underground stormwater detention systems during the first year of operation. Monthly or quarterly inspections are needed at this time to ensure the newly installed structure is performing as intended. After that, the inspection schedule may be modified to meet specific stormwater permit requirements.


Real Results

iStormwater LLC was an excellent choice. They made the process of the Stormwater pond repairs seamless. They took charge of the project and got the project approved and passing the inspection. We highly recommend them and would use them again.

Lyonswood HOA

Incredible stormwater management service. The owner John consulted on a property I manage and ended up saving us thousands of dollars in environmental fees from the government. Now, our property is compliant with the EPA and we have a great partner to keep us maintained on stormwater regulations over time.

Kelly E.

So helpful with all of my water issues.

Kel R.

Great communication and leadership and a family friendly atmosphere. Thank you John!

Brian D.
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