Stormwater Management Techniques

In This Section

Low Impact Development (LID) Strategies

The following are examples of current stormwater management techniques that involve LID strategies:

Bioretention Cells: Traditional bioretention cells, also referred to as rain gardens, are small landscaped, graded areas constructed with a special soil mix and lined with a porous medium that can aid in reducing stormwater runoff, replenishing the aquifer, and filtering nonpoint source pollution. Low maintenance, water-tolerant plants are often used in bioretention cells. Bioretention cells also can be designed using waterproof liners with underdrains, which can collect stormwater for reuse and help avoid potential soil contamination and leaks into building foundations. At Federal Triangle, the Ariel Rios South Courtyard bioretention cells are lined, while the Constitution Avenue cells are not. For more information on bioretention cells, see the Office of Water's bioretention applications fact sheet (PDF) (3 pp, 135K, About PDF).


Cross-section	Constitution Avenue construction	Constitution Avenue completed

Cisterns: Cisterns are storage tanks that can be designed to capture stormwater runoff. Stormwater diverted and collected in cisterns can be used to supplement or replace existing potable water for uses such as irrigation, toilet flushing, and cooling towers.


Cross-section of Ariel Rios cistern	Ariel Rios cistern tank installation	Recycled glass art panel installation in Ariel Rios cistern


Close up of Ariel Rios cistern beneath recyclable dome	Completed Ariel Rios cistern	Completed Ariel Rios cistern at night

High Density Plastic Grid: This is a flat grid made of high density plastic that is used to reduce soil compaction and maintain infiltration in lawns subject to vehicle traffic. This permits traffic to cross the area and still allow water to infiltrate into the grass.


Sketch of high density plastic grid.	Grid installed beneath grass on Constitution Avenue

High Efficiency Irrigation: Irrigation techniques, timers, and moisture sensors can be utilized to reduce excess watering and promote water conservation. Furthermore, stormwater runoff can be collected in cisterns, which in turn can be used in place of potable water in these more efficient irrigation systems.


Irrigation head	Irrigation cap denoting non-potable water source	Water management equipment

Permeable Concrete: This is a specially mixed concrete product with most of the fine aggregates, or stones, removed from the concrete mixture. Eliminating the fine aggregates creates pores that permit water to travel through the concrete to a stone reservoir underneath the pavement, thus allowing stormwater to be filtered, detained, or infiltrated into the ground.



Under-drain with liner	Course stone/base layer	Fine stone/finish layer

	Path Completed

Permeable Pavers: Permeable pavers are used to intercept and transmit runoff to permeable soils or gravel layers where pollutants are filtered, runoff is slowed, and aquifers are replenished. A gravel storage reservoir used in conjunction with pavers can hold large amounts of water to help control the timing and volume of runoff. The pavers, made of concrete, brick, or recyclable plastic, can be incorporated into grassy and open areas or installed as roadways or parking surfaces. For more information see the Field Evaluation of Permeable Pavements for Stormwater Management (PDF) (2 pp, 66K, About PDF).


Cross-section	Stone filled between openings	Paver patio completed

Runnels: Runnels are surface depressions in sidewalks that safely channel small amounts of stormwater runoff. At Ariel Rios South Courtyard, runnels channel stormwater to the cistern for reuse in the irrigation system.


Sketch of a runnel.


Sloped runnel to drain	Cobbles sloped to form runnel

Soil Amendments: Compacted soil does not absorb water well and therefore, increases runoff. To correct this problem, soils can be improved through tilling and/or adding organic material, fungi, worms, and topsoil. These processes restore the soil's water absorption and filtering capacity. Other benefits include reduced lawn maintenance, lowered irrigation, and healthier plants.


Trenching soil	Trenches with amendments being added

Sustainable Landscaping: Sustainable plant species thrive with minimal maintenance. Most are native plants that are well adapted to local conditions and best suited to respond to and/or reduce stormwater runoff. View the sustainable landscaping planting plan or the Ariel Rios South Courtyard plant list. For more on this topic, visit EPA's WaterSense Program, Greenacres, or Mid-Atlantic Region Green Landscaping Web sites.


Planting plan	Plant installation	Completed landscape

Other Sustainable Techniques

The following are examples of current stormwater management techniques that do not involve LID strategies:

High Efficiency Lighting: Energy-efficient light fixtures are installed to light the walkway and cistern. Lighting contains low voltage and fiber optic lamps with daylight sensors and timers.


Fiber optic lighting inside cistern	Low voltage path lighting

Recycled Content Materials: The site furniture is made from recycled metals and plastics. Recycled concrete and aggregates are also used in the construction of pavement bases.


Plant sign made from farm tools	Recycled content patio furniture	Recycled plastic used for walls of control bunker

Recycled glass cistern cover	Historic granite curb removal	New location and use for historic granite curb as bench

Water-Efficient Historic Fountain: Another feature added to the historic fountain at the Ariel Rios South Courtyard is a recirculating pump that reuses water and eliminates the need for continuous potable water use.

Photo of the historic fountain at Ariel Rios South Courtyard.

Renovated fountain

Stormwater Management Techniques

In This Section

Low Impact Development (LID) Strategies

The following are examples of current stormwater management techniques that involve LID strategies:

Other Sustainable Techniques

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