JAUNTS : Sanitation Ponds a Birds’ Paradise : A naturalist will lead a walk through the large odor-free Ventura complex, which is home to herons, egrets, ducks, cormorants and others.

Bird-watching on the grounds of Ventura’s sewage treatment complex sounds like an outing for only the most unflappable of bird buffs.

But the vast sanitation operation near the Ventura Harbor includes a wildlife refuge with three ponds that draw a big bird population. And, happily, it’s virtually odor-free.

Susan Williams, a naturalist with the city’s recreation department, is leading a bird walk around the ponds Sunday from 3 to 4:30 p.m. It’s a chance to see herons, egrets, ducks, cormorants, maybe a turtle basking on a rock or a family of muskrats.

“We never know what we’ll find,” Williams said. Like the time one of her groups came across a turkey vulture feasting on a dead sea gull. It made a more lasting impression on the kids in the group than, say, the hundreds of coots, ducks and other birds that calmly cruise the ponds.

The walk starts at the Surfers’ Knoll parking lot, on the beach side of Spinnaker Drive where Williams leads the group through a locked fence. Inside, the three ponds cover a total of 34 acres. A dirt road, about one mile long, encircles them.

It’s not exactly a wilderness area with the harbor, sewage treatment plant and beach nearby. But it still has a secluded feel. Trees and bushes surround the ponds, animals skitter about and birds chatter.

Williams has an uncanny ability to spot birds that would go unnoticed by most people. She provides binoculars and spotting scopes for walkers to get a closer look. (The scopes work better for children who can’t handle binoculars.)

Along the way, she tosses out little informational nuggets: “The cormorants don’t have oil glands to waterproof their wings, so after a dive they drip-dry.” The coots: “They do this kind of Egyptian number with their necks.” And the herons: They’re one of the shyer birds, preferring the most remote pond.

The water in the ponds, built in 1973, has already been treated by the city so it is odor-free, except for a whiff of chlorine at one spot. The ponds are really reservoirs, supplying irrigation water for golf courses, parks and other properties. Whatever is left over flows into the nearby Santa Clara River estuary.

During the week, the city allows the public to walk out by the ponds. But visitors must first sign in at the administration building off Spinnaker Drive. Bird groups visit frequently.

The spot is also a cushy retreat for migratory birds that use the ponds as a stopping off place where they can rest and feed before resuming their journey.

“In January and February it’s wall-to-wall ducks,” Williams said. “It’s incredible.” As April approaches, some of the migratory birds are still laying over. Other birds stay year-round.

Williams isn’t just a bird buff. She has degrees in marine biology and environmental science; she has been a research scientist and a consultant for an oil company; she teaches at Oxnard College; and for the last four years she has led nature programs for the city.

On the walk, she might talk about the disappearing wetlands in California. Or, the Chumash Indians--how they used the nearby willow trees to build their homes. She might point to the blisters on the leaves of a willow where the sawfly has deposited its eggs.

The walks attract families, as well as adults. Williams doesn’t enforce a no-talking rule to enhance bird sightings; in fact, she gets a little exuberant when she spots a rare find. But she does have noise limits, she said.

“We discourage screaming.”

Details

* WHAT: Bird walk, approximately one mile.

* WHERE: Around three ponds on the grounds of Ventura’s sanitation treatment complex near the Ventura Harbor. Group meets at Surfers’ Knoll parking lot, off Spinnaker Drive, across from Ventura Harbor Village.

* WHEN: Sunday, 3 to 4:30 p.m.

* COST: $3 per person. Preregistration is required. Children under 5 are free, but must be in a child carrier because strollers are not allowed.

* ETC: Call 658-4726 for information.

* FYI: The wildlife ponds at the sewage treatment complex are open to the public during the week. Visitors must check in at the sanitation administration building, 1400 Spinnaker Drive. For information, call 562-4544.