Page 98 - Florence County, SC Florence County 2032: Connecting Our Past, Defining Our Future

WHAT DOES LID LOOK LIKE?

LID practices mimic the natural processing of stormwater runoff and can create more attractive communities. LID
techniques and strategies are listed below.

VEGETATED FILTER STRIP VEGETATED SWALE BIORETENTION CELL / RAIN GARDEN
RELATIVE
COST
$$
LID TOOLBOX MAINTENANCE ACTION As needed LID TOOLBOX LID TOOLBOX
Semi-Annually
Annually
Monthly
Pruning
Weeding
Mowing
Water
Remove Trash
Remove Dead Vegetation
Repair Erosion
Repair Sediment Build Up
Repair Ponding
General Inspection
A vegetated filter strip is a band of vegetation, A vegetated swale is a wide, shallow channel with Bioretention cells, or rain gardens, are
vegetated depressions layered with
STORMWATER PLANTER BOX
BIOSWALE vegetation covering the sides and bottom. Swales are PERVIOUS PAVEMENT
usually a mix of grasses and native plants that
engineered soil media that filter pollutants,
acts as a buffer between an impervious surface
designed to convey and treat stormwater, promote
and a waterway. They are designed to slow LQÀOWUDWLRQ UHPRYH SROOXWDQWV DQG UHGXFH UXQRII YHORFLW\ increase the time water stays on the site, and
PERMEABLE PAVEMENT
runoff from adjacent impervious surfaces, filter Vegetated swales mimic natural systems better than provides stormwater storage. These systems
pollutants, and provide infiltration (depending traditional drainage ditches. usually have an underdrain to ensure the cell
upon the permeability of underlying soils). They drains in a reasonable time period. Although
can also provide aesthetic benefits, stormwater Vegetated swales can be used on sites that naturally they are applicable in most settings, rain
storage, and wildlife habitat. In addition to LID TOOLBOX LID TOOLBOX cultivate a dense vegetative cover and have an gardens are best used on small sites, urban
stormwater management, vegetated filter strips DSSURSULDWH DUHD VORSH DQG LQÀOWUDWLRQ SRWHQWLDO 6ZDOHV areas, suburban areas, and parking lots. Rain Garden, Kempwood Manor
can add recreational value with opportunities are most effective when used in a treatment train with (Image: EHRA)
to incorporate trails into their design. other LID techniques. They are widely used to convey
LID TOOLBOX
and treat stormwater runoff from parking lots, roadways,
Filter strips are best suited on sites that Vegetated Filter Strip, Lone Star College and residential and commercial developments and are
naturally support dense vegetation. Filter Victory Center compatible with most land uses.
strips are best used in treating runoff from
roads, roofs, small parking lots, and other (Image: Asakura Robinson)
small surfaces.
Vegetated Swale, Federal Reserve Bank Rain Garden, Dickinson Library
RAINWATER HARVESTING (Image: Asakura Robinson) (Image: Asakura Robinson)
Designing for Impact | 21
20 | Designing for Impact Rainwater harvesting systems are above- or below-ground storage containers that capture 22 | Designing for Impact
and store runoff to be used for irrigation and other nonpotable uses. Rainwater harvesting
systems are an appropriate LID technique for highly urbanized areas, where impervious
surfaces are unavoidable and site constraints limit the use of other LID practices. These Permeable pavement is a durable, load-bearing paved
systems are also a sustainable building practice that reduce demand on municipal water
surface designed to allow water to pass through and into
Bioswales are similar to bioretention cells in A stormwater planter box is a bioretention system enclosed an underlying rock base. Due to the prevalence of clay
CONSTRUCTED
resources. Systems range in size and complexity and include rain barrels, cisterns, and
soils in this region, runoff flows through the permeable
underground storage.
STORMWATER WETLANDS
CISTERN
RAIN BARREL
design and function but are linear elements in a concrete container that contains porous soil media and LID TOOLBOX pavement and is directed to an underdrain, subsurface
detention, or rainwater harvesting system. Permeable
that can also be used for conveyance and vegetation to capture� detain� and filter �tor��ater runoff� pavement allows for streets, parking lots, and sidewalks
storage in addition to their biofiltration Stormwater planter boxes are lined, contain an underdrain, to mimic pre-development runoff conditions while
sustaining the functional attributes of the site area they
function. They can be used anywhere and are
have various small to medium plantings, and are installed
LID TOOLBOX best used on small sites, in urbanized and below or at grade level to a street, parking lot, or sidewalk. an� �ontrol runoff �olume an� pea� flow rates�
replace. Permeable pavements reduce pollutant loads
suburban commercial areas, residential areas,
Permeable pavement includes a wide range of materials,
Runoff is directed to the stormwater planter, where water is
such as permeable stone pavers, porous asphalt, and
and parking lots.
porous concrete. These materials can be used as a
filtered by vegetation before percolating into the ground or
roadways, playgrounds, and plazas.
used to irrigate the tree or other vegetation in the planter box.
Bioswale, Bagby Street discharging through an underdrain. The stormwater is also LID TOOLBOX substitute to conventional pavement on parking areas, Permeable Pavement, Kempwood Manor
(Image: H-GAC) (Image: H-GAC)
In addition to stormwater control, stormwater planter boxes
offer on-site stormwater runoff treatment and aesthetic value.
Stormwater planter boxes are optimal for urban or streetscape Designing for Impact | 25
environments. Stormwater Planter Box, Darling Street
(Image: Jones + Carter)
Bioswale, Houston Permitting Center
(Image: H-GAC)
24
Designing for Impact | 23
| Designing for Impact
Rain barrels are small
Constructed stormwater wetlands are manmade shallow- systems that guide runoff Cisterns are large rainwater systems
GREEN ROOF
UNDERGROUND STORAGE
water ecosystems designed to treat and store stormwater through a downspout into installed above or below ground with
runoff. These wetlands allow pollutants to settle out or a barrel that usually holds As illustrated, a range of
a much larger capacity than rain
to be treated by vegetation. Runoff is slowly discharged less than 100 gallons. barrels. They can store water from
over one to three days. Wetlands provide plant and Rain barrels are typically multiple downspouts and pavement
wildlife habitat and can be designed as a public amenity. installed and maintained by techniques can be utilized
areas.
While constructed stormwater wetlands have limited single-family homes.
applicability in highly urbanized settings, they are a to achieve low-impact
desired technique on larger sites with relatively flat or LID TOOLBOX
gently sloping terrain. They are also well-suited to low- LID TOOLBOX
lying areas, such as along river corridors. Rain Barrel, Ghirardi WaterSmart Park Rain Barrel, Residence in Houston development (LID). It is
(Image: H-GAC) (Image: Asakura Robinson)
important to determine that the
Designing for Impact | 27
technique selected to mimic a
Stormwater Wetlands, Mason Park
(Image: H-GAC)
26 | Designing for Impact site’s predevelopment hydrology
Cistern, Grocery Store in Houston
Cistern, Houston Arboretum
(Image: Asakura Robinson) (Image: H-GAC)
is consistent with the character
28 | Designing for Impact
of the built environment.
Underground storage systems capture A green roof is a vegetative layer grown on a rooftop that
and store runoff below grade in large ÀOWHUV DEVRUEV DQG RU GHWDLQV UDLQIDOO 7KH JUHHQ URRI
Source: Designing for Impact: A Regional Guide to Low Impact Development. Houston-Galveston Area Council.
system typically contains a soil layer, a drainage layer,
chambers. The stored runoff is usually
used for irrigation. If the soils are and an impermeable membrane. Water is captured and
suitable, a portion may also infiltrate into detained in the soil and dispersed through evaporation
underlying soils. Underground storage or transpiration by the plants. Green roofs reduce
may be used for stormwater detention volume and peak rates of stormwater and enhance water
instead of surface ponds. If used under TXDOLW\ 2WKHU EHQHÀWV LQFOXGH UHGXFWLRQ LQ heat island
parking, this method of detention effect, extension of roof life, recreational and gardening
Adopted - August 19, 2019
can increase the land available for opportunities, air and noise quality improvement, and | 91
development. reduced building heating and cooling costs. xii They can
be integrated into new construction or added to existing
EXLOGLQJV LQFOXGLQJ EXLOGLQJV ZLWK ÁDW DQG VORSHG URRIV
This practice is effective in urbanized areas where there
is little room to accommodate other LID systems.
Underground storage tank, Birnamwood Drive
(Image: Harris County Public Infrastructure Department) Green Roof, Houston Permitting Center
(Image: H-GAC)
30
Designing for Impact | 29
| Designing for Impact