We are barely into the 21st century and already the Houston area has dealt with Tropical Storm Allison and Hurricane Ike—not to mention other countless, nameless storms. This reality means that a Houston landscape design pretty much demands a well-thought-out storm drainage system. Like irrigation systems, a storm drainage system is an unsung hero of your property. Both systems help your landscape flourish, come rain or shine.

Expertise Required

In addition to the antics of Mother Nature, storm drainage issues are very serious in Houston 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 with Exterior Worlds.

Storm Drainage: Parts and Pieces

• Gutter downspout tie-ins. Downspout tie-ins are designed to take water from the gutters to the landscape drainage system. These connections 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, water can be used to dig deep trenches and expose roots, which also minimizes damage.

Storm Drainage: 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.

Storm drainage impacts residential landscape maintenance as well. Since it drains water from low-lying areas, it prevents 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.