Design Detail: Pad Area

The pad is maintained as open lawn space to accommodate the farmers' market, additional event parking, and recreational use. Stormwater entering the site from the culvert is directed into an engineered pretreatment vault with minimal above-ground footprint to keep as much usable pad area as possible. Trash, sediment, and oils are separated in the vault. The pretreated water then flows into a vegetated swale that runs around the southern edge of the pad. The water is filtered and cleaned by soil and plant roots and a portion is infiltrated into the ground. Overflow is directed into the existing drainage, where it is cleaned further before flowing into the estuary. Densely growing shrubs, grasses, and flowering plants along the swale create a beautiful border along the pad for visitors to enjoy and learn about green stormwater management.

swale

Play area Vendor vehicle access

Farmers' Market

Bioswale

The pad area is graded to redirect water around the periphery of the open space through the use of swales and a slight elevation in the northeast corner.

3:1 side slope

Vegetated swales are broad shallow channels densely planted with vegetation. Swales are designed to slow runoff, filter/absorb stormwater pollutants, and promote infiltration. They can be easily integrated into the landscape setting and provide both stormwater management and aesthetic value.

Stormwater Pretreatment Device

Oil/trash separation Clean-out hatch

Outlet to swale

The existing swale along the north side of the pad is rehabilitated and extended into a very broad, shallow swale that runs along the new drive. This allows water to flow toward the existing drainage during very wet periods, but the area is still usable for parking or recreation most of the time. During farmers' market days, these spaces are reserved for visitors with limited mobility.

Shrubs and small trees are planted along Main Street to screen views of the commercial businesses across the street but still allow visibility of the farmers' market for passers-by.

The new accessible trail linking the Church Street entrance with the existing gravel path provides easy access to the farmers' market to pedestrian visitors coming from the south.

A children's play area located between the pad and the new segment of trail is far enough downslope to be sheltered from undesirable noise and view from the road, and is easily accessible from either the trail or the farmers' market. This provides a safe space for children to play away from potential vehicle traffic. Shady areas beneath the mature trees lining the former driveway provide additional space to relax.

Inlet (from culvert) Sediment trap

Stormwater pretreatment devices are typically prefabricated structures with small footprints, making them ideal for constrained spaces. Specific configuration and features vary by manufacturer, but most units separate sediment, oil and grease, and trash from runoff before the flow discharges into the main treatment structure (e.g., detention basin, swale), protecting that structure from being overwhelmed with pollutants and extending its functional life. Accumulated material must be periodically cleaned out of the pretreatment unit, typically with a vacuum truck or small excavator through an access hatch at the top.

Vegetated Swale Management

Annually or after large storms:

• Inspect and correct any erosion or damage, especially near the inlet. • Inspect for and remove any debris or accumulated sediment >3" in depth or covering vegetation. • In spring, inspect for and remove any accumulated sand. Consider mulching and aerating to restore soil structure.

As needed:

• Replace dead or damaged vegetation. • Reseed bare areas; install appropriate erosion control measures if necessary.