Treasure island

A manmade stream transforms a North Coast garden
Lauren Bonar Swezey

One spring day, as the rain-splashed flagstone in her Fort Bragg, California, front yard created the illusion of a pond, Sarah Forseter realized that her garden was missing a vital element: a water feature. With the help of Fort Bragg landscape designer Peggy Quaid, she created a naturalistic "stream" that traverses the garden.

The stream ― about 54 feet long ― is actually two ponds that appear to join (a single stream of the same size would have been costlier and destroyed more of Forseter's existing garden). The segment pictured above flows across one side of the garden; it begins as a shallow stream, then gently spills into a 3-foot-deep pond filled with goldfish.

Flexible liners covered with river rocks line the bottoms of the ponds; to hide the liners' edges, Forseter planted low-growing thyme and geraniums. Dwarf conifers, sedge, and society garlic punctuate the banks.

To keep algae in check, Forseter installed ultraviolet pond lights. A pump in each pond recirculates water through a filter; a float hooked to a water line and spigot automatically adjusts the water level of each.