The City’s Stormwater Management Program, including the capital improvement projects like this Victory Farm Stormwater project, are funded by a Stormwater Program Fee that is assessed to all owners of impervious area. The fee is reflected on a property owner’s tax bill, but it is a utility fee rather than a tax. You can learn more about how the fee and the program work here.

The conceptual change from a 100% wet pond to the 50% wet pond and 50% temporary pond design with a smaller footprint was driven exclusively by early feedback from the community. The City wasn’t aware of the potential cost savings until after the change was made.

The project is expected to provide “full” water quality treatment. “Full” quality management is defined by Maryland’s Stormwater Design Manual as removing 80% of total suspended solids (grit or dirt – the stuff that makes the water brown and silty when it rains), and 40% of total phosphorus, which represents the environmentally damaging nutrients we want to take out of the runoff water. The performance standard set by the State roughly represents reasonable limits on stormwater management technologies. A pond like the one the City is proposing does this quality management by giving stormwater runoff time in the pond for the grit to drift to the bottom, where it can’t wash down the stream, and through the biochemical systems in a pond that take up and transform nutrients, such as when an aquatic plant uses the nutrient to grow a little bigger. Trash and oil and heavy metals are also managed, but there isn’t currently a numeric standard for these pollutants. While the project is focused on providing quality treatment to make the water cleaner, the type of facility proposed offers some water “quantity” control management, too, so that the water is slowed down and temporarily detained, which helps reduce erosive forces and flooding downstream.

The Victory Farm stormwater plans do not take the school site into account from a water quality treatment perspective. The new elementary school is already subject to Montgomery County regulations such that MCPS will be providing full treatment for the new impervious area at the school site. Even though the school will be providing quality treatment for its own new impervious area, the increase in impervious area will be accounted for in the Pond and Stream Restoration designs for big flood event storms that are not managed at the school site. To be clear, the flood event storms aren’t necessarily “treated” at the proposed pond either, but the pond has to be designed to withstand those flood waters to be as safe as possible.

A “trash rack” will cover the outflow openings. It is basically a grate that prevents larger trash and debris from leaving the pond while also preventing the larger debris from clogging the openings. As trash accumulates in the pond, routine maintenance will be performed to collect and dispose of the trash.

During dry weather, the pond will be approximately 8-12 feet deep in most places, which would cause water to pond back in the stream channel approximately 450 feet away from the dam. During rain events, the pond may fill up to a depth of roughly 13 feet or more depending on the intensity of the rain event.

Recreational use such as swimming, kayaking, canoeing, and boating would be prohibited for safety reasons.

Algae blooms are possible and are typically a result of the nutrient pollution that the pond is intended to capture. The pond will be planted with emergent vegetation to help reduce algae blooms. The City has standard maintenance procedures to respond to nuisance algae blooms should they occur.

The pond is being designed with relatively deep pools and is large enough to host a stable aquatic ecosystem. These features discourage mosquito breeding as wind-disturbed surfaces on the open water discourage egg-laying and natural predators manage larvae populations. Proper pond design and proper pond maintenance will keep mosquitoes at a low risk.

While the existing wetland provides stormwater management benefits for Tributary 1A, the design of the pond is intended to replicate and enhance the treatment capacity at this location. The loss of the wetland area is unfortunate, but it will not reduce the treatment capacity of the proposed stormwater facility. In addition, it is not feasible to retain the wetland and provide a pond due to limitations on ponding depths and elevations. In order to create a pond with the wet pool that can provide the full targeted treatment, the immediate vicinity behind the dam has to fill up a certain amount. This elevation floods the existing wetland area to a point that it can no longer be sustained as a wetland.

: Several methods for restoring the stream segments were explored and reviewed for their merits. One method that provides the least disturbance to the riparian buffer includes hard armoring the stream to force stability. While this method largely leaves the riparian buffer untouched, it does not address root causes of stability issues and rather propagates erosive forces downstream to other vulnerable reaches. In addition, this method does not have as much potential ecological uplift and is more akin to a man-made drainage system. More impactful methods were also reviewed that would have allowed the design team to control flows more effectively with larger floodplain areas in the riparian buffer. These designs were passed over due to the extensive construction disturbances. The broadly defined natural channel design option is being used with practices that are mostly limited to instream locations to minimize construction disturbances. In order for these designs to effectively reduce energy and provide habitat, some practices outside of the stream banks are used. Regenerative step pools are considered and in fact some step pools are included in the design were applicable to navigate particularly steep slopes without widening the disturbance footprint. This practice cannot be used in all locations and is not sufficient in itself to reduce flow energy throughout the riparian corridor. The current design is still conceptual. As the project team moves forward it will continue to look for opportunities to preserve existing natural resources, reuse disturbed natural resources, and generally minimize impacts to the forested parkland.

The effects of the emerald ash borer are widespread. Despite the damage being done by the borer, the Green Ash isn’t an endangered or threatened species and there are plenty of seeds still existing in the seed bank of our forests. The City isn’t currently taking extra precautions with respect to preserving the local ash trees unless there is a particularly healthy tree in a more urban setting where a seed bank is not expected to exist.