Louisiana Yards and
Neighborhoods
www.lsuagcenter.com/lyn
Reduce Stormwater
Runoff
Reduce Stormwater Runoff
• Stormwater runoff
– Definition
– Problems
– Solutions
• Best Management
Practices (BMPs)
– Prevent runoff
– Vegetative cover
• Alternatives
• Groundcovers
– Reduce pollutants
– Fertilizer
– Pesticides
Hydrologic Cycle
• Water on earth is constantly recycled
• Components of water cycle:
– Soil Infiltration
– Evaporation
– Transpiration - the process by which
plants release water into the atmosphere
– Surface and channel storage
– Groundwater storage
The soil matrix filters
and somewhat
detoxifies impurities
from water as it
travels through the
ground.
Urbanization
Intensity of land use
Amount of impervious surfaces
Water quality degradation
Nonpoint source pollution
Sources of pollution that cannot be
pinpointed to any single cause. Usually
associated with trash, car oil, chemical
lawn products and other residues that
are easily carried away by flowing
water.
Stormwater Runoff - Rainwater that flows off
yards, roads and parking lots, carrying
pollutants into our waterways.
According to the EPA, polluted runoff is the
#1 water quality issue in Louisiana
Nutrients
Toxins
Sediments
Thermal Stress
Debris
Pathogens
Photo courtesy of NEMO
Stormwater Contaminants
Metals
zinc, cadmium, copper, chromium,
arsenic, lead
Organic chemicals
pesticides, oil, gasoline, grease
Pathogen
viruses, bacteria, protozoa
Biochemical oxygen
demand (BOD)
grass clippings, fallen leaves,
human and animal waste
Sediment
sand, silt and other particles
Salts
sodium chloride, calcium chloride
Nutrients
nitrogen, phosphorus
The Problem
• Increased volume of surface runoff
• Increased velocity of surface runoff
• Concentration of pollutants in runoff
Elevated nutrients can cause:
– Polluted drinking water
– Excessive aquatic plant growth
– Lower dissolved oxygen levels
– Fish kills
The Solution
• Use practices or methods to prevent,
reduce, retard or remove stormwater
runoff contaminants before reaching
receiving waters.
• Best Management Practices (BMPs) are a
series of direct recommendations based
on research, evaluation and educated
assumptions.
Be Louisiana Friendly
Regardless of the type of property
you own, you can help preserve
Louisiana’s natural resources by:
1) Preventing runoff
2) Increasing vegetative cover
3) Reducing pollutants
Prevent Runoff
Keep rain and irrigation water
on your property and out of
storm drains.
Factors Affecting
Stormwater Runoff:
•
•
•
•
•
•
Rainfall intensity, flow rate, season
% impervious surfaces
Watershed size, slope
Soil type, soil compaction
Type of vegetation
Density of vegetation
 Within our control
 Not within our control
Minimize Runoff by Using
Pervious Surfaces…
for walkways, patios
and driveways
Direct Downspouts and Gutters
Toward Porous Areas
If downspouts drain to planted areas, be sure to
select plants adapted to periodic flooding.
Collect Rain Water
Use a rain barrel or a cistern to collect and
store runoff for irrigation purposes.
Cistern
Plan Irrigation Schedules
According to the Weather
• Water during early morning
hours.
– Plants are already wet.
– Less evaporation losses.
• Water less frequently in cooler
months.
• Water “as needed,” not routinely.
• Do not irrigate if rain is
expected.
Earth Shaping
If your property is sloped, you may want to
make minor grade changes to divert runoff.
This can be accomplished with terraces.
Terracing can be an
attractive design element
in your yard.
Berms and Swales
Creating swales (low areas) and berms
(raised earthen areas) will help to catch,
hold and filter storm water.
Elevations and depressions as small as 3-6
inches can make a huge difference.
Vegetative Cover
Planting groundcovers on slopes is an
excellent way to:
• Catch and filter storm water.
• Slow the velocity of water movement.
• Reduce erosion.
Turf grass is a versatile
groundcover that is
effective at filtering
nutrients.
Covering the Ground With a
Carpet of Vegetation Has Other
Advantages
• Attractive
• Insulates the soil
• Acts as a living mulch that
helps build up humus
levels in the soil
• Provides habitat and cover
for beneficial insects and
other predators
Blanketflower
Gaillardia pulchella
Disadvantages
• If the ground cover is
too vigorous, it may
require containment.
• It can compete with
other plants for water
and nutrients.
Sweet potato
Ipomea batatas ‘Margarita’
The following factors should also be taken
into account, when choosing the right plant
for the right place…
Select Plants Based on Site
Conditions
•
•
•
•
•
•
•
Acid, alkaline - (test your soil’s pH)
Dry, moist
Full sun, shade
Heat, cold
Salt
Space
Obstructions
Periwinkle
Catharanthus roseus ‘Diva’
Alternative Groundcovers
For Shaded Areas
Lilyturf
Liriope muscari
(USDA Zone 6-11)
Periwinkle
Vinca major
(USDA Zone 8-11)
Cast Iron Plant
Aspidistra elatior
(USDA Zone 8-11)
Alternative Groundcovers
Beach Sunflower
Helianthus debilis
(USDA Zone 8B-11)
Perennial Peanut
Arachis glabrata
(USDA Zone 8-11)
Clover
Trifolium repens
(USDA Zone 5-11)
Alternative Groundcovers
For Sunny Areas
Asiatic Jasmine (USDA Zone 8-11)
Trachelospermum asiaticum
Junipers (USDA Zone 8-11)
Juniperus spp.
Tree Canopy
Incorporate trees in the landscape
– Intercept rainfall
– Reduce soil compaction, thus
improving water infiltration into soil
– Increase the property
value
– Energy efficient way
to cool the home
Reduce Pollutants
Because water can wash off our yards, it is
important to reduce the amount of
pollutants on our property.
• Sweep grass and soil
back onto lawns.
• Sweep up any fertilizer on
impervious surfaces.
• Remove trash.
• Clean up oil spills and
leaks with cat litter.
• Pick up after pets.
It is unrealistic, even unwise, to strive for an
insect, disease and weed-free yard. Instead:
• Learn to identify key pests
associated with the plants in
your yard.
• Check plants regularly for
signs of pest problems.
• Determine what amount of
damage warrants action.
Manage Yard Pests Responsibly
• Avoid routine applications
of pesticides.
• Choose the least harmful
method of control.
• Treat only affected area
rather than spraying the
entire yard.
Fertilize Appropriately
If applied improperly, excess fertilizers can run
off our yards into waterways or leach into
groundwater.
• Follow printed
instructions
carefully!
• Do not apply
fertilizer or
pesticides before a
heavy rainstorm.
Louisiana Yards and
Neighborhoods
www.lsuagcenter.com/lyn
Reduce Stormwater
Runoff