Sitting at about 39 feet above sea level with 21 major bayous in the greater metropolitan area and recipient of regular tropical storms, Houston landscapes pretty much demand drainage systems. Like irrigation systems, drainage systems are the workhorses of your property, helping your plant material to flourish and your home to be safe regardless of Mother Nature’s antics.
Drainage Systems: Parts and Pieces
- Gutter downspout tie-ins. Downspout tie-ins are designed to take water from the gutters to the landscape drainage system. These tie-ins are made of plastic, metal or brass and sometimes have a side cleanout with a see-through grate so they can be easily inspected for clogs.
- Catch basins, or yard drains. Catch basins can be placed under downspouts when it is undesirable or not possible to tie into the gutter. They tie into a PVC main drain line instead and carry water out through the landscape drainage system. Catch basins are usually a plastic or concrete box that uses a plastic or metal drain grate cover to filter out leaves and other waste debris.
- Channel drains. These long narrow strip drains are used between main structures and paving or at the edge of a patio or deck.
- French drainage. Designed to take water away from saturated soil, French drains are small ditches that are filled with undersized rocks or gravel.
- Deck drains. Deck drains are installed in patios, decks and walkways so that water is either sloped toward drains or drained into the landscape beds. They have special drain covers, usually decorative, made of metal, brass or stone. Deck drains are smaller in size than catch basins and are only intended to drain patio surface areas.
When installing a yard drainage system, it is recommended to hand-dig trenches around trees to minimize damage to them. It is best to tunnel under tree roots by using compressed air. This tree preservation method exposes tree roots so they are not torn. Alternately, pressurized water can be used to dig deep trenches and expose roots, which also minimizes damage.
Drainage Systems: Affect on Other Systems
Drainage systems and irrigation systems can work in concert with each other. Landscape designers or landscape architects can develop a whole-system approach so that the nuts and bolts of both systems are hidden as much as possible. When that is not possible, the use of custom decorative drain gates can be used to reduce the negative visual impact. The design and location of the two systems should be seamless with the rest of the landscape design.
Drainage systems impact residential landscape maintenance as well. Since they drain water from low-lying areas, they prevent standing water that can cause slippery surfaces, mosquito breeding grounds and drowned landscaping. A proper landscape drainage system is essential for the care of your lawn as it moves water off of your property in a timely manner, thus encouraging healthy grass and allowing your maintenance crew to perform their regular lawn service duties.
In Houston, storm drainage issues are very serious due to our flat topography, dense clay soils, and heavy forested lots compacted by years of construction that have increased impervious surfaces. These factors have caused more streets and homes to become flooded during the heaviest rainfalls. Consequently, local ordinances are beginning to follow the model used by the Memorial Villages that require minimum pipe sizes, flow rates, temporary drainage systems, engineered drainage plans, calculations, topographic maps, and as/built plans.
“If drainage contractors embark on a drainage project without a thorough understanding of these demands, homeowners may find themselves drowning in a big mess that can cost thousands to rectify,” says Jeff Halper, landscape design specialist with Exterior Worlds.
Since 1987, Exterior Worlds has been providing high-end landscape design and services for the Memorial Villages, including Piney Point Village, Hunter Creek Village, Bunker Hill Village and Hedwig Village, Tanglewood, River Oaks, West University, Bellaire, and the greater Houston area. Call them at 713-827-2255 to discuss drainage systems for your property.