Comprehensive Environmental Inc (CEI) - LID Committee - New Boston, NH Raingarden Demonstration Project

For more information on these raingardens follow the links below.

This photo was taken on June 11, 2005.

Comprehensive Environmental Inc (CEI) provided funds for this Low Impact Design (LID) raingarden Project located in the Merrimack River watershed, in the Town of New Boston, New Hampshire. CEI's LID Committee personnel served as the technical consultants for this project to identify a location for the project, design the raingarden, as well as providing the labor for the actual construction.

The project location had to fit several criteria:

an area that could capture and infiltrate stormwater runoff discharging to nearby stormdrains and eventually to the Merrimack River watershed
an area that was visible to the public
an area that would provide an educational benefit

The area at the end of the homeowner's driveway was chosen for the raingarden. It would collect all of the runoff from the lawn and some from the gravel driveway.

An educational sign was installed in the rain garden.

Construction of Rain Garden

On April 29, 2005 the garden area was excavated, and on April 30, 2005 the garden was landscaped. Because of multiple storms the plantings were not placed until June 12, 2005. The garden was completed on June 12, 2005.

A 3 foot hole was excavated in the center of the garden. The raingardens are dug so that they are tied into soils that lie below the normal frostline. Stone or slotted PVC tubing is then used to promote drainage in the bottom of the raingarden. This keeps the drainage working during winter months, preventing total freezing. The holed areas were then covered with filter fabric and filled with rocks provided from the excavated area.

The rock area was covered with the filter fabric and a 4" mixture of 50% native soil and 50% compost was spread over the garden area landscaped so that a depressed area was formed.

The compost-amended soil has many potential benefits when instituted with establishment of turf and landscaping, including:

increased water conservation,
increased nutrient retention,
better turf aesthetics,
reduced need for chemical use,
improved stormwater retention, and
cost-savings to the private landowner.

The area was planted with live plants on June 12, 2005 and a two inch Hemlock mulch covering, was placed to prevent erosion from the exposed soils and to protect the plants.

Native plants were selected for their ability to grow in various depths of water and soil moisture conditions.

Pre Construction Photos

Desired location	Desired location

During-construction Photos (April 29-30, 2005)

Preparing area	Digging hole	Filling hole with filter paper


Filling hole with rock	Covering rock with filter paper	Landscaping area


Landscaping area	Final landscaped area	Final landscaped area

Click any thumbnail for a larger view. Photos above taken by CEI LID Committee members.