La Kretz Urban Watershed Garden


The LaKretz Urban Watershed Garden is a public garden designed to teach the principles of water conservation.  It compares a natural watershed with an urban one, showing ways to preserve precious water.  It is also a valuable educational resource for the more than 10,000 schoolchildren who visit TreePeople each year.

TreePeople visitors enter the garden through an enormous concrete storm drain pipe.  Once inside, they see a small scale river winding its way through a natural landscape to the clean ocean. 

Near this river are two models showing the movement of water through an urban area:

On the traditional side, it rains on the rooftop, garden, sidewalk and driveway of a house.  This water picks up oil and trash which it carries through the gutter and drain pipe to the ocean.  This is the 'city' model that most people recognize from their own homes and neighborhoods, and this is the ocean we see full of oil and trash every time it rains. 

On the opposite side, the rooftop, garden, sidewalk and driveway have been modified to allow the rainwater to filter back into the soil rather than carry pollutants to the ocean.  This is achieved via:

  • Trees that shade the roof of the house and capture rainwater through its roots.
  • A rain barrel that captures rain directly from the roof  - this rain can be used later to water the garden.
  • Mulch and native plants in the garden that allow rainwater to soak into the soil (rather than run off hard-packed dirt).
  • Contours in the natural garden (bioswales) that hold water in the garden so it has time to soak in, rather than reaching the driveway or street.
  • Breaks in the concrete and natural ground that allow more water to soak into the ground rather than run off.

Although these modifications may appear slight, their impact is great – very little of the rain from this side reaches the ocean.  

By walking through the La Kretz Watershed Garden, visitors can see how small changes in their living environment really make a difference in conserving water.   We hope that visitors to the Garden will be inspired to conserve one of our city’s most precious resources.