1. Drainage Issues in the Landscape Virginia Cooperative Extension Prince William County Master Gardeners Lorrie Andrew-Spear Frank Reilly

2. Shameless Commercial Gardening Series Gardening Series Help Line Help Line

3. Drainage Issues in the Landscape A. Where does the water come from and why doesn’t it go away? A. Where does the water come from and why doesn’t it go away? B. Impact of drainage problems B. Impact of drainage problems C. Drainage solutions C. Drainage solutions

4. A. Where does the water come from and why it doesn’t go away Precipitation, ground water, surface water Precipitation, ground water, surface water Watersheds Watersheds Physiographic regions and soil types Physiographic regions and soil types Soil texture and structure (particle sizes, pore spaces, well-drained soils vs. not, organic component, compaction) Soil texture and structure (particle sizes, pore spaces, well-drained soils vs. not, organic component, compaction) Soil horizons and water infiltration Soil horizons and water infiltration Run off (erosion, potential pollutants) Run off (erosion, potential pollutants)

5. Precipitation, ground water, surface water

6. Groundwater – Surface Water

7. Watersheds What is a watershed? What is a watershed? What is your watershed? What is your watershed? How can you find out? How can you find out? http://www.epa.gov/sur f/ http://www.epa.gov/sur f/ http://www.epa.gov/sur f/ http://www.epa.gov/sur f/ http://www4.pwcgov. org/website/pwc-gis/ http://www4.pwcgov. org/website/pwc-gis/ http://www4.pwcgov. org/website/pwc-gis/ http://www4.pwcgov. org/website/pwc-gis/

8. Prince William County Watersheds This county crosses 3 watersheds. This county crosses 3 watersheds. watersheds Find environmental information for each of these watersheds: Find environmental information for each of these watersheds: –02070008 Middle Potomac- Catoctin; state(s): DC, MD, VA, WV 02070008 –02070010 Middle Potomac- Anacostia-Occoquan; state(s): DC, MD, VA 02070010 –02070011 Lower Potomac; state(s): MD, VA 02070011

9. Run Off Flooding Flooding Erosion Erosion Potential pollutants Potential pollutants

10. Run off affected by: Impervious surfaces Impervious surfaces Slope Slope Vegetation Vegetation Previous moisture Previous moisture Infiltration rate Infiltration rate

11. Physiographic regions and soil types Physiographic Regions describe land surface features Physiographic Regions describe land surface features Closely related to geology Closely related to geology Slope, and soils are related Slope, and soils are related

12. Appalachian Plateaus Appalachian PlateausAppalachian PlateausAppalachian Plateaus Valley and Ridge Valley and RidgeValley and RidgeValley and Ridge Blue Ridge Blue RidgeBlue RidgeBlue Ridge Piedmont Plateau Piedmont PlateauPiedmont PlateauPiedmont Plateau Coastal Plain Coastal PlainCoastal PlainCoastal Plain Physiographic Regions

13. Soil Structure GranularBlocky PrismaticPlaty Columnar Single Grained Massive

14. Soil Texture

15. Sand are the largest particles and they feel "gritty." Sand are the largest particles and they feel "gritty." Silt are medium sized, and they feel soft, silky or "floury." Silt are medium sized, and they feel soft, silky or "floury." Clay are the smallest sized particles, and they feel "sticky" and they are hard to squeeze. Clay are the smallest sized particles, and they feel "sticky" and they are hard to squeeze. Sand 2.00 - 0.05 mm Silt 0.05 - 0.002 mm Clay < 0.002 mm

16. Pore Spaces The smaller the particles The smaller the particles The smaller the pore spaces The smaller the pore spaces Water moves slowly Water moves slowly Less air present Less air present

17. Pore Spaces can decrease due to compaction

18. Soil horizons and water infiltration Horizons have different properties Horizons have different properties Some may retard water flow Some may retard water flow Watch out for the “builder’s horizon” Watch out for the “builder’s horizon”

19. Check for Yourself Dig a hole 12 inches deep and fill it with water Dig a hole 12 inches deep and fill it with water 30 minutes, the soil has a drainage problem 30 minutes, the soil has a drainage problem 24 hours, waterlogged soils may impact plant growth 24 hours, waterlogged soils may impact plant growth

20. B. Impact of drainage problems Home damage Home damage Puddles (mud, mosquitoes) Puddles (mud, mosquitoes) Eroded topsoil, rills, gullies Eroded topsoil, rills, gullies Lawns and plants (stressed – drowned) Lawns and plants (stressed – drowned)

21. Home Damage

22. Puddles Mosquitoes Mosquitoes Mud Mud Further damage Further damage

23. Eroded topsoil, rills, gullies

24. Erosion – Where do you think it goes?

25. Lawns and plants (stressed drowned)

26. Drainage Problems Damage at your home Damage at your home Damage Down Stream Damage Down Stream –Watershed level –Neighborhood level Keep the water safely on your property Keep the water safely on your property