Residential Solutions

Small scale residential projects include all projects that increase impervious area by more than 500 square feet. These projects are not required to complete formal hydrologic analysis or to get approval from the Upper Los Angeles River Water Master (ULARWM).

The basic objectives for these projects include:
  • Reducing a site’s impervious surfaces
  • Improving a site’s ability to infiltrate stormwater
  • Conserving stormwater runoff for other onsite water demand uses
  • Reducing negative impacts downstream

The specific small scale residential solutions include the following: 

  • Driveway cross (or drain with metal grate)
  • Dry/Gravel swales
  • Dry wells
  • Permeable pavements (or porous pavement systems)
  • Planter boxes
  • Rain barrels & small cisterns
  • Rain gardens
  • Vegetated swales


Infiltration trenches are linear ditches that collect rain water from adjacent impervious surfaces. They are dug in areas where they can intercept this surface flow and their highly permeable fill allow water to quickly infiltrate into the ground. The primary purpose of infiltration trenches is to treat stormwater quality. As rain falls on impervious surfaces and flows downhill across the surface collecting pollutants that are present on the surface, the infiltration trenches intercept the flow and filter out the pollutants while also providing groundwater recharge.


Gravel swales are often used to capture infiltrated storm water from either roof or impervious surface run off. They are designed to hold water for a short period of time and induce infiltration. Swales generally have a trapezoidal or parabolic shape with relatively flat side slopes.


A dry well is a trench or basin completely filled with coarse media, such as angular gravel, to create a porous layer for infiltrating runoff.


Impervious walkways and driveways can be removed and replaced with permeable paving such as “pavers.” Pavers are brick-like materials that are manufactured in a variety of shapes. Pavers fit together like tiles and are set with small gaps between them, creating grooves for water to infiltrate the soil beneath. Other materials such as broken pieces of recycled concrete can be used. Paved walkways can also be removed and replaced with gravel or mulch.

A rain garden is a shallow depression that captures rainwater and allows it to soak into the ground. Plants help to filter the rainwater as it moves through the soil layer. A rain garden is most often planted with native species creating an ecosystem on properties where birds, butterflies and beneficial insects thrive.

Vegetation in swales allows for filtering of pollutants and infiltration of runoff into groundwater and generally treat small drainage areas. Densely vegetated swales can be designed to add visual interest to a site and enhance the aesthetic value of a residential property.

Oros Green Street 400x215