drainage issues in the landscape virginia cooperative extension prince william county master...
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Drainage Issues in the Drainage Issues in the LandscapeLandscape
Virginia Cooperative ExtensionVirginia Cooperative ExtensionPrince William CountyPrince William County
Master GardenersMaster GardenersLorrie Andrew-SpearLorrie Andrew-Spear
Frank ReillyFrank Reilly
Shameless CommercialShameless Commercial
• Gardening SeriesGardening Series
• Help LineHelp Line
Drainage Issues in the Drainage Issues in the LandscapeLandscape
• A. Where does the water come from and why A. Where does the water come from and why doesn’t it go away?doesn’t it go away?
• B. Impact of drainage problemsB. Impact of drainage problems
• C. Drainage solutionsC. Drainage solutions
A. Where does the water A. Where does the water come from and why it come from and why it doesn’t go awaydoesn’t go away• Precipitation, ground water, surface waterPrecipitation, ground water, surface water• WatershedsWatersheds• Physiographic regions and soil typesPhysiographic regions and soil types• Soil texture and structure (particle sizes, pore Soil texture and structure (particle sizes, pore
spaces, well-drained soils vs. not, organic spaces, well-drained soils vs. not, organic component, compaction)component, compaction)
• Soil horizons and water infiltrationSoil horizons and water infiltration• Run off (erosion, potential pollutants)Run off (erosion, potential pollutants)
Precipitation, ground water, Precipitation, ground water, surface watersurface water
Groundwater – Surface Groundwater – Surface WaterWater
WatershedsWatersheds
• What is a What is a watershed?watershed?
• What is your What is your watershed?watershed?
• How can you How can you find out?find out?
• http://www.epa.gov/shttp://www.epa.gov/surf/urf/
• http://www4.pwcgohttp://www4.pwcgov.org/website/pwc-v.org/website/pwc-gisgis//
Prince William County Prince William County WatershedsWatersheds• This county crosses 3 This county crosses 3
watershedswatersheds. . • Find environmental Find environmental
information for each of information for each of these watersheds: these watersheds: – 0207000802070008 Middle Middle
Potomac-Catoctin; Potomac-Catoctin; state(s): DC, MD, VA, WVstate(s): DC, MD, VA, WV
– 0207001002070010 Middle Middle Potomac-Anacostia-Potomac-Anacostia-Occoquan; state(s): DC, Occoquan; state(s): DC, MD, VAMD, VA
– 0207001102070011 Lower Potomac; Lower Potomac; state(s): MD, VAstate(s): MD, VA
Run OffRun Off
• FloodingFlooding
• ErosionErosion
• Potential pollutantsPotential pollutants
Run off affected by:Run off affected by:
• Impervious Impervious surfacessurfaces
• SlopeSlope
• VegetationVegetation
• Previous moisturePrevious moisture
• Infiltration rateInfiltration rate
Physiographic regions and Physiographic regions and soil typessoil types
• Physiographic Regions describe land Physiographic Regions describe land surface featuressurface features
• Closely related to geologyClosely related to geology
• Slope, and soils are relatedSlope, and soils are related
Appalachian Plateaus Appalachian Plateaus Valley and RidgeValley and Ridge
Blue RidgeBlue Ridge Piedmont PlateauPiedmont Plateau
Coastal PlainCoastal Plain
Physiographic Regions Physiographic Regions
Soil StructureSoil Structure
GranularGranular BlockyBlocky
PrismatiPrismaticc
PlatyPlaty
ColumnaColumnarr
Single Single GrainedGrained
MassiveMassive
Soil TextureSoil Texture
Soil TextureSoil Texture
• Sand Sand are the largest particles and they feel "gritty."are the largest particles and they feel "gritty."• Silt Silt are medium sized, and they feel soft, silky or are medium sized, and they feel soft, silky or
"floury.""floury."• Clay Clay are the smallest sized particles, and they feel are the smallest sized particles, and they feel
"sticky" and they are hard to squeeze."sticky" and they are hard to squeeze.
Sand Sand 2.00 - 0.05 2.00 - 0.05 mmmm
Silt Silt 0.05 - 0.002 0.05 - 0.002
mmmm Clay Clay < 0.002 mm < 0.002 mm
Pore SpacesPore Spaces
• The smaller the The smaller the particlesparticles
• The smaller the The smaller the pore spacespore spaces
• Water moves Water moves slowlyslowly
• Less air presentLess air present
Pore Spaces can decrease due Pore Spaces can decrease due to compactionto compaction
Soil horizons and water Soil horizons and water infiltrationinfiltration
• Horizons have Horizons have different propertiesdifferent properties
• Some may retard Some may retard water flowwater flow
• Watch out for the Watch out for the “builder’s horizon”“builder’s horizon”
Check for YourselfCheck for Yourself
• Dig a hole 12 inches Dig a hole 12 inches deep and fill it with deep and fill it with waterwater
• 30 minutes, the soil 30 minutes, the soil has a drainage has a drainage problem problem
• 24 hours, 24 hours, waterlogged soils waterlogged soils may impact plant may impact plant growth growth
B. Impact of drainage problemsB. Impact of drainage problems
• Home damageHome damage
• Puddles (mud, mosquitoes)Puddles (mud, mosquitoes)
• Eroded topsoil, rills, gulliesEroded topsoil, rills, gullies
• Lawns and plants (stressed – drowned)Lawns and plants (stressed – drowned)
Home DamageHome Damage
PuddlesPuddles
• Mosquitoes Mosquitoes
• MudMud
• Further damage Further damage
Eroded topsoil, rills, gulliesEroded topsoil, rills, gullies
Erosion – Where do you think it Erosion – Where do you think it goes?goes?
Lawns and plants (stressed Lawns and plants (stressed drowned)drowned)
Drainage ProblemsDrainage Problems
• Damage at your homeDamage at your home
• Damage Down StreamDamage Down Stream– Watershed levelWatershed level– Neighborhood levelNeighborhood level
• Keep the water safely on your Keep the water safely on your propertyproperty
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