How to Eliminate Stormwater Runoff: Installing a Home Drainage System
During the construction of a two-story addition to her bungalow, a homeowner in Santa Monica, Calif. was required by local regulations to install a water flow management system. The City of Santa Monica requires the infiltration or retention of 100 percent of stormwater runoff from new development projects, but the property was too small for an infiltration system or an engineered natural treatment.
At first, the homeowner just paid the city’s $8,000 fee to discharge the runoff into the street, but then began pursuing other options since releasing water so close to the ocean can be hazardous. The city recommended a concrete cistern, with a final cost that could have ranged anywhere from $10,000 to $30,000. Then, a civil engineer guided the homeowner to NDS, Inc. for selecting a much more cost-effective and sustainable stormwater solution.
To fix her problem, the homeowner’s contractor chose to install a system comprised of three types of drainage products: an French drain, a dry well, and a pop-up emitter.
French drain
A lightweight and all-in-one drainage solution, NDS’s EZflow french drain requires no gravel. Polystyrene aggregate completely surrounds the outside of a drainage pipe, providing a consistent infiltrative area for the absorption and removal of water. Uniform size and shape of the aggregate delivers optimal permeability.
Dry well
Easy to install, NDS’s Flo-Well dry well is made from 100 percent recycled materials and offers a sustainable way to manage stormwater runoff. Capable of operating independently or as part of a larger stormwater management system, Flo-Well units collect, retain and direct stormwater on a site without the need for gravel and a traditional dry well. Modular units can be connected in a series or stacked to accommodate a variety of needs and site limitations.
Pop-up emitter
Acting as the discharge point of a drainage system, NDS pop-up emitters release water from the drain pipe away from structural foundations in order to help manage water overflow. A spring-loaded cap opens when it senses the hydrostatic pressure of water flowing through the pipe, and it closes again when the flow decreases. The pop-up style keeps rodents and debris out of the system, and the low-rise height won’t get in the way of mowers.
The drainage system on the homeowner’s property was designed to convey water from the south to the north, which takes place in the narrow portions of yard on both sides of the home and drains into two NDS Flo-Well dry well units that retain and direct stormwater without the need of a traditional dry well. To prevent stormwater overflow, NDS pop-up emitters were installed to release excess water into the street.
As for most NDS drainage systems, the homeowner’s solution installation required minimal excavation, and complete installation took about two weeks. Since the primary challenge with her property was limited yard space, the scalable and flexible nature of NDS products made them easily adaptable to the specifics of the project, as a concrete cistern would have been too invasive for her property. To conserve even more space on the property, contractors added piping to the side lawn segments above the EZflow, instead of alongside it.
Since installing the drainage system in 2012 at a total cost of about $3,500, we’re happy to report that our homeowner in Santa Monica has not experienced any overflow issues.
For more information about these drainage solutions and to learn how to select and install products for a particular drainage problem, visit NDS’s Home Drainage Center.
