Stormwater Management Projects: Catch Basins and Dry Wells

What are Stormwater Management Projects?
Roadside drainage improvements (catch basins, dry wells, roadside ditch improvements) that protect the lake from nonpoint source pollution carried by stormwater runoff.   Stormwater runoff is the number one source of pollutants in Lake George.... so these projects can make a huge difference to water quality!

In 2004, the LGA hired Myers Engineering to identify and prioritize potential stormwater remediation projects along the Rt. 9N corridor.   Since 2004, the LGA has funded and implemented several of these projects.

Examples of Stormwater Management Projects:

Photo credit: Warren County Soil & Water Conservation District

Lake George Village - Dry Wells & Infiltration Chambers - February 2007- Present

Dry wells and infiltration chambers were installed at fifteen separate locations within the village, in a heavily developed section of the watershed. The dry wells installed were eight feet in diameter, with depths ranging from five feet up to twelve feet. These systems can capture and infiltrate a significant volume of stormwater runoff. The sandy soils within the village of Lake George have relatively high infiltration rates and are effective at filtering out and removing pollutants as the stormwater travels through the soil.

Consequently, Prospect Mountain Brook suffers from less bank erosion during storm events, and its base flow is increased (water is recharged back into the soil where it eventually feeds the stream, instead of running off the pavement directly into the brook).

In addition, this project addressed a runoff problem at the Lake George Village Department of Public Works.  One acre of impervious surface drained directly to Prospect Mountain Brook. Vehicle washing, salt storage, and other pollutants were directly discharging to the brook through a large drop inlet and direct pipe to the stream. This project corrected this problem and also improved the streambank.

This initial project was a collaboration between the Warren County Soil and Water Conservation District, the village of Lake George, the NYS Department of Environmental Conservation, the LGA (with Helen V. Froehlich Foundation funds) and the NYS Dept. of State (with funds provided under Title 11 of the Environmental Protection Fund).

The dry well devices have been so successful that Warren County Soil and Water has continued to work with the village of Lake George to install 30 additional dry wells, for a total of 45 within the village alone. This represents a tremendous amount of runoff that is getting infiltrated into the soil instead of flowing directly into Lake George.

Brereton Road (Bolton) - 2008
A drop inlet with a 5' x 5' catch basin was installed to contain sediment and debris.  Brereton Road was a ‘high priority’ site identified in the LGA 2004 Rt 9N Stormwater Study - pdf. This particular project involved removing a drop inlet and replacing it with a larger 5’ x 5’ catch basin. The larger catch basin has a large sump that will allow sediment and other materials to drop out of stormwater as it passes through the structure. The stormwater then passes under the road and downhill to the Lake. A second catch basin was added to the south side of the road to capture additional runoff and sediment. Prior to the addition of the catch basin, stormwater was running down to the Lake mostly untreated. This project took place in the fall of 2008 and expenses were shared with the Lake George Watershed Coalition (LGWC) via the NYS Dept. of State with funds provided under Title 11 of the Environmental Protection Fund.

Coolidge Hill Road (Bolton) - Fall 2008
A 4' x 4' dry well was added at the end of a stone-lined trench to catch sediment and stop erosion. Coolidge Hill Road was a ‘high priority’ site identified in the LGA's 2004 Rt 9N Stormwater Study - pdf. When first identified, drainage on both sides of the road was a concern. The Warren County Department of Public Works addressed some of the problems, but erosion continued on a short section of the property, and this erosion led directly into Edmonds Brook. The dry well captures runoff and allows it to infiltrate into the ground, filtering out any sediment or debris. Overflow is taken via an underground pipe directly to the brook. Expenses were shared with the Lake George Watershed Coalition (LGWC) via the NYS Dept. of State with funds provided under Title 11 of the Environmental Protection Fund.

Indian Brook (Bolton) - 2009 - 2010
A roadside ditch was stabilized and a swale was lined with stone to prevent erosion. Check dams were added to slow down water running down Federal Hill Road and into the brook. Additional shoulder work allowed some stormwater sheet flow to occur over a vegetated area. The remaining shoulder work reinforced and directed the flow around a bend in the road to a small basin to contain the stormwater. Other improvements, including a sediment basin and streambed plantings, were also made at Indian Brook.

What is a Catch Basin?
A catch basin is part of a storm drain or sewer system. It acts much like its name implies - it catches stormwater. Stormwater enters the catch basin from either an inlet culvert or a grate on the top. Typically, the outlet is designed with a sump (or basin area) that allows sediment and debris to drop out and be stored. A catch basin traps debris so that it cannot enter drainage pipes, essentially treating stormwater before it reaches the Lake or a stream. Catch basins come in a variety of sizes and sump depths. They do not allow for any infiltration of the stormwater into the ground.

Catch basin maintance requires regular clearing of the grating and surrounding area so stormwater can reach the basin. Sediment and debris trapped in the bottom needs to be cleaned out with a catch-vac or large vacuum truck. If the catch basin is not maintained, the trapped sediment will begin to overflow with the stormwater, rendering the device useless in treating stormwater.

What is a Dry Well?
A dry well is a cylindrical underground cement structure with perforated sides. It is placed in locations that will allow it to receive stormwater runoff. The stormwater and associated debris and sediment that is carries is stored in the dry well. As the water dissipates from the dry well, it infiltrates into the ground. The debris and sediment are left behind to be cleaned out periodically or as needed.