In the summer of 2021, the City of Rockville experienced massive flooding from Tropical Storm Ida. As a result of the storm and other recent intense rain events, the Potomac Woods neighborhood has experienced significant flooding effects, including damage to resident properties and increased stream bank erosion in Potomac Woods Park. Stormwater improvements will be completed in three phases.
The goals of the project are to:
- Reduce flooding on resident properties and lower the risk of property damage.
- Improve stream health by reducing erosion and sediment pollution.
- Protect infrastructure by stabilizing banks and outfalls.
- Restore function of the stormwater facility.
Project Phases
The first phase focuses on maintenance and repairs to stormwater features within Potomac Woods Park.
- Maintenance of the Potomac Woods Park pond (Task A): The Potomac Woods Park stormwater pond was built in 1998 and retrofitted in 2014. The connected stormwater pond has been inspected frequently and has had regular maintenance, including trash and debris removal. A recent survey was conducted which indicated 42% loss of stormwater capacity and dredging is needed to restore its function.
- Stream spot repair and replacement of failed gabion wall (Task B): The storm drain outfall pipe in Potomac Woods Park was installed in 1977 and later required the installation of a gabion wall (a large metal basket filled with rocks) to stabilize the pipe and prevent collapse of the pedestrian path. The pipe has since fallen into disrepair and the gabion wall is on the verge of collapse. This repair is a priority due to the impacts that the collapse of the gabion wall could have on the stream, pedestrian path, nearby sewer, and other recreational facilities.
In January 2024, the city contracted Bayland Consulting to create designs for both the pond dredge and the stream spot repair. The design is planned to be completed in 2025, with construction anticipated to begin in the spring of 2026.
Budget for Phase 1:
- Cost of Design: $218,000 in total.
- Cost of Construction: $1,060,000 in total.
Before photos:
The second phase upgrades the neighborhood storm drain system to reduce flooding within the neighborhood. In response to flooding from Tropical Storm Ida, the city reviewed the capacity of storm drain systems and identified the Potomac Woods system, built in 1963, as needing improvement to improve stormwater capture. Problematic flooding has been identified at the grate inlet behind 1998 Lancashire Drive and the curb inlet in front of 1382 Kersey Lane. Homes in both areas have sustained property damage.
In June 2024, the city contracted Charles P. Johnson and Associates to design storm drain improvements, including a repaired system outfall in Potomac Woods Park. The city plans for the design to be completed in 2025, with construction anticipated to begin in 2026.
This project was selected to receive nearly $740,000 in federal earmark funding.
Budget for Phase 2:
- Cost of Design: $206,000 in total.
- Cost of Construction: $1,337,000 in total.
Before photo:
The third phase involved regrading the intersection of Lancashire Drive and Milboro Drive.
There has been increased community concern related to standing water and a siphon within the storm drain network in front of 1885 Milboro Drive. The former siphon structure also required regular attention and maintenance by city crews.
The city worked with its on-call contractors to regrade this intersection in the fall of 2024. The upgraded intersection allows drainage to flow down Lancashire Drive and negates the need for the siphon structure. The siphon inlet structures were removed to avoid any future maintenance issues.
Budget for Phase 3:
- Cost: $50,000 in total.
Project Timeline
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Project InitiatedMay 2022 -
Storm Drain Analysis CompletedApril 2024
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Community MeetingFall 2025
Contact
Gina Arnett
Public Works Department
Engineering Division
240-314-8517
garnett@rockvillemd.gov
Hours
Monday – Friday
8:30 a.m. – 5 p.m
Address
Rockville City Hall
111 Maryland Ave.
Rockville, MD 20850