Drainage is a widely misunderstood landscaping issue. Water collecting or standing in your yard for several hours after a rain is not a drainage problem. But water standing for two days or more after a rain could definitely be a problem. There is one very important premise with drainage…water flows naturally downhill and uphill by only mechanical means. However, determining where “downhill” is and getting water to flow efficiently in that direction sometimes is not as simple as it may seem. An accurate assessment of the situation is necessary before the problem can be corrected properly.
There are two basic types of drainage dilemmas and each has different solutions.
PROBLEM: SURFACE WATER
The most common problem is surface water. There is water running through your yard, or water stands for several days at a time after a strong rain. This would probably indicate improper contouring of the landscape or building site, a pretty common problem for modern builders these days. Correcting the contour can sometimes solve the problem.
Solution #1: Berms and Swales
There are two methods employed to change a site’s contour. One solution is to lower the soil level with a swale, a shallow ditch that catches water and moves that water to another location. The other solution is the complete opposite – raising the soil level by constructing a berm that interrupts the flowing water path and moves it around the raised earth, creating a new path.
Solution #2: Surface Drain
A different approach to the dilemma of surface water is to install a surface drain that feeds into a pipe, which moves the water to a different location. Most often moving water across the surface is preferable to using a pipe and drainage system due to the fact that swales and berms are adaptable; they can be moved, reshaped and are easier to maintain. Piping has a limited volume of water it is able to move and can get clogged over time with debris or roots.
PROBLEM: SUBSURFACE WATER
A subsurface drainage problem is indicated by ground that stays wet for long extended periods of time.
Solution #1: French Drains
Using a French drain system can drain soggy, wet and saturated soil. The standard French drainage system uses porous piping surrounded by gravel to carry water downhill to a suitable location for discharge. A trench is dug through the area where the water is collecting and a perforated plastic pipe is place in the trench with the perforations at the 5 and 7 o’clock positions. Gravel is then poured around the piping material to backfill the trench. Excess water then fills the spaces around the gravel and then moves into the drainage pipe to be carried away.
Solution #2: Submersible Pumps
If you happen to have an area that seems to consistently collect water with no way to move it downhill, a submersible pump can be placed in a shallow collection well to pump the water uphill to your discharge location. The collection well can be purchased commercially, or you can create your own by digging a hole two or three feet deep and lining it with large aggregate or gravel. Excess water will collect in the well and an automatic switch in the form of a float can turn the pump on as the well fills and off as it empties out. There are issues to address with this solution however; The pump needs a power source, so electricity will have to be run to it, and during storms when your heaviest rains occur, you may lose power, disabling your pump when you need it most.
Sometimes a combined system could be the smartest idea depending on your situation. Areas that are naturally wet and need a French drainage system can also benefit from a surface grate that will collect water during rains and move it throughout the French drain before it adds to the subsurface problem.
Drainage does not have to be a difficult dilemma, but a correct assessment of the problem and possible solutions is needed before you start digging trenches that rival the Mississippi River!
Question: Jimmie, I read your recent article in the Prosper Magazine and am now so ready to start playing in my landscape. You had some really good tips. I have a question about my Red Tip Photinias. I have some that are covered badly with leaf spots and is now starting to affect my Indian Hawthornes as well. How do I control this problem?
-Terri T. from Prosper
Answer: Hi Terri! Thanks for your inquiry. Photinias are one of the most infected shrubs with “fungal leaf spot” which is what you’re describing. Most landscapers will no longer warranty Photinias due to that reason. The disease itself is an airborne bacterial fungus. To be totally honest with you your best bet long term would probably be to replace the Photinias with another type of shrub that is not susceptible to the fungus. However, if you choose to treat it, the best chemical to use on it is Daconil. It can be purchased at a good nursery or anywhere that carries a good supply of Ortho products. You will apply the infected areas by spraying every 10 days until you see all new growth coming out disease free. Use the same treatment with the Hawthornes. There are also some fungicide products that help too. Keep a close eye on the Photinias after that, it’s very likely to come back.
Hope this helps you out. Until next time, happy gardening!!
Jimmie is a Prosper resident and the owner of Absolutely Bushed Landscaping Company, an award winning, family and veteran owned and operated business created in 1980 to provide the highest quality custom Outdoor Renovation available to homeowners in the Dallas Ft. Worth area.