FREQUENTLY ASKED DRAINAGE QUESTIONS

A SWALE DRAINAGE system is a general purpose shallow open surface channel with sloping sides that collects water and allows it to percolate into the ground, reducing the amount of runoff leaving a road or property. The grass covering the side slopes and swale bottom provides a filtration surface for the water and helps to reduce flow velocity.

The average cost range to install a SWALE DRAINAGE is approximately $20 per linear foot depending on the overall size, depth, grading and soil type.

A FRENCH DRAIN SYSTEM is intended to keep water away from a foundation and is a trench filled with a perforated pipe, then gravel and wrapped in geotextile woven fabric that will allow water to drain naturally from the landscape. Depending on the size of the property and the scale of the drainage issue including; pipe diameter, linear feet, type of soil to dig, pipe, gravel and fabric material installed will ultimately drive the cost with any add ons like decorative covers or connecting to a rain garden or other water retention system.  

The average cost to install a French drain is approximately $50 per linear foot.

The CANAL DRAINAGE SYSTEM is similar to a swale drain but typically deeper to carry more water farther distances. A canal can also act as a resource for irrigation and deliver water where needed, and away from those unwanted areas. 

The average cost to install a Canal Drain is approximately $30 per linear foot to  $300 per linear foot depending on additional materials used such as concrete and other aggregates.

CULVERTS are a type of drainage pipe or channel built into roads, railroads, and bridges to give an opening underneath the surface for water to flow. Drainage ditches, often found on roadsides, provide a nearby, safe location for stormwater to go.

The average cost to install a driveway type culvert can range from $1500 to $3000. 

Trench drains may also be called channel drains and are a linear drainage application used to collect and carry water to an outlet or catch basin.  These are considered an above-ground drainage solution. Its materials are embedded in the ground within a long, narrow trench. It has a grated covering that may look like guttering and are typically used when vehicles or pedestrians need to travel across the drain. 

The average cost of a channel drainage system varies from $180 to $500 per foot.

BERM DRAINAGE is a ridge or barrier constructed of compacted soil, gravel, rocks, and stones to prevent, divert, or direct water away from a particular area. It is constructed as a level space or mound that separates two areas.

The average cost of a berm installation will vary between utilizing onsite soil and aggregates versus hauling in and delivering materials to form required berms.

RAIN GARDENS are depressed areas in the landscape planted with vegetation and designed to collect rainwater, filter out pollutants, and soak the water into the ground. Rain gardens capture, store, and infiltrate rainwater in a bowl shape. 

A rain garden cost varies considerably, ranging from $10 per square foot to $35 per square foot, depending on the source of the materials and location.

RETENTION PONDS are wet detention basins or storm water management ponds (SWMP) and typically have vegetation around the perimeter and a permanent pool of water in its design. It is used to manage stormwater runoff, for protection agains flooding and erosion control, and serves as an artificial wetland to improve the water quality in adjacent bodies of water.

CATCH BASINS are essentially a drainage solution for landscaping systems. This item typically contains a grate with a pipe used to drain excess water through and away from the area.

An INTERCEPTOR DRAINAGE SYSTEM, also known as a curtain drain, is a drainage system that is installed to collect, channel and remove surface and subsurface water within permeable soil as it flows across an impermeable soil layer.

At the top of slopes to stop runoff from eroding the hillside.
Along driveways, roads, or paths to prevent washouts.
Around foundations or basements to divert water away and reduce moisture.
On construction sites to control stormwater flow.
In agricultural fields to manage irrigation runoff or prevent flooding.