Managing Storm Water Control in Multifamily
The frequency of extreme weather events in some parts of the country has landscapers and water conservationists rethinking storm water drainage and landscape design. While excessive rainfall and heavy runoff or flooding has swept away drought, it has also left some landscapes tattered and in need of repair.
Dealing with water control in property management
Earthworks, Inc., which specializes in apartment landscape design and maintenance, has had its fair share of clean-up calls from heavy rains in North Texas.
“We had more events of extreme weather in 2015 than I remember,” said President Chris Lee. “I can remember several times having 8-10 inches of rainfall in a night, but not five times in the same year.”
It’s not uncommon for 100-year floods to occur frequently, according to the U.S. Geological Survey. In fact, hydrologists say there is a misconception about the term which might suggest that the average person may see only one such extreme weather event in a lifetime.
Statistically, 100-year floods have a 1 percent chance of occurring in any given year. But that 1 percent could happen two years in a row, or maybe even more than once in the same year.
In Texas and parts of the Midwest, that number has been called more than once in recent years and caused significant flooding. During Thanksgiving in 2016, North Texas received 3-5 inches of rain, much of it coming down in a span of few hours. In May, up to 6 inches fell overnight in Dallas.
Tarrant Regional Water District offers way to solve drainage problems
Storm water control specialists say that landscapes need to be ready to manage storm water runoff in the event severe weather happens anytime. Excessive runoff and flooding not only wipes out flower beds and plant life but also can cause structural damage. Lee says it’s time for apartments to consider addressing water runoff to minimize the potential for damage.
“A lot of people are looking at solving drainage problems,” he said. “But it’s not easy. At times, it’s complicated. If it’s a fairly level, flat property, not much slope or drop, it’s hard to move water long distances without the use of pumps, which we try to avoid because they always work until you need them to.”
He suggests considering looking beyond traditional spring color plantings and take note of a project recently completed by the Tarrant Regional Water District (TRWD), which supplies much of the water for the Dallas/Fort Worth area.
System is eco-friendly and designed to withstand weather extremes
The TRWD Demonstration Landscape is an environmentally-friendly solution to managing normal and excessive runoff without using unsightly drainage ditches and canals. In 2015, TRWD did a makeover of the grounds near the north side of its Fort Worth office complex near the Trinity River to help preserve the landscape during heavy downpours and manage drought. The new look, which took about six months to complete, transformed a heavy sloped, grassy area with traditional mulch beds and plant life into a sustainable park-like setting.
Dry river beds with large, native stone covering an aggregate-based drainage system absorb and move water away from one of the administration buildings into a rain garden where water is infiltrated into the ground. One portion of the dry river bed actually runs uphill on a downgrade toward the river, but underground drainage takes the water away.
Aggregate-based and pervious concrete walkways designed to absorb water and minimize runoff lead to a gathering area in the middle known as the lecture circle.
The area, which looks like a flower from overhead, also features native, drought-tolerant grasses and plant life. Zoysia, Bermuda and a new drought-tolerant St. Augustine grass developed by Texas A&M’s AgriLife division fill areas in between walkways the jut from a long pervious concrete sidewalk resembling the stem.
“It looks very cool and is really functional,” Lee says. “It’s essentially sustainable but they’ve done it in such a way that it better deals with heavy rains and droughts. They are able to capture water in ponds and retain some of that for different things if they need to, or let is slowly percolate into the ground versus flooding down a hill carrying topsoil and rocks and everything else with it.”
Project is a solution for apartments to manage excessive runoff
A TRWD official says the system has a number of benefits beyond redirecting water that frequently washed out mulched beds and required additional attention from the water district’s landscape contractor. The system also increases infiltration, protects water quality and reduces the need for irrigation, pesticides and fertilizer usage.
Subsurface drip irrigation is hidden beneath mulch to gently water plant roots where needed. Native and adaptive plants like Buffalo Grass that require less water, pesticides and fertilizer surround a concrete lecture circle encompassed by pervious concrete. A demonstration showed how water from a garden hose was absorbed through the pervious concrete while it ran off the concrete lecture circle.
Darrel Andrews, TRWD’s environmental division assistant director, said the area was designed to show how homeowners and multifamily properties can manage landscapes to withstand the extremes of Texas weather while going easy on the environment.