While at the CalTrans press conference on water conservation today, I had the chance to talk to Stephen Alvarez, a CalTrans senior landscape architect, about why the agency plants landscaping that needs to be irrigated regularly. The agency typically waters its landscaping three times a week during summer, while many native plants survive here with only what they can gather from the winter rainfall or the atmosphere.

Why plant landscaping that needs irrigation at all? Plants occur naturally here.

In order to establish plants, they need to be watered initially.

I’m not talking about initially. Why the ice plant on the side of the road? Why pick any plant that needs irrigation?

It evolved with time. This plant out here (he gestures at the road shoulder) needs a little bit of irrigation, but it’s very drought resistant. It served a functional need. It covers the ground very quickly, which helps keep the weeds down. We’ve used it to keep the weeds down, as fire suppression when a cigarette butt falls out, it’s nice and juicy — it doesn’t spread, it keeps the fire down. And it has an aesthetic appeal. It uses 30 percent of turf grass. It draws a lot of what it needs from the air.

What about CalTrans ice plant — your signature plant.

That’s our signature plant. But we are looking at different options now, native plants. We’re trying to get plants that with time, water can be turned off. But every single plant needs water initially.

You keep saying initially, but you still have ice plant that you water three times a week during the summer. Why plant something that you have to water as much as someone waters their yard?

We’re trying to limit those things more, and limit those plantings more. If you look at this slope (across Interstate 805), the ice plant is somewhat stressed. (It looks yellow.) We’re keeping it alive for fire suppression and erosion control. We have a duty to do functional planting, and we have a duty to make sure it establishes.

Anywhere you go in San Diego, the natural landscape here, plants take the winter rain and that’s it.

That’s true. But remember, we’ve been landscaping since the 1960s. So we have a tremendous inventory out there. It’s going to take some time to wean those systems off. It would be very difficult to just shut the water completely off, because we’d have erosion problems, fire issues, we’d have other functional problems.

But you could also plant plants that …

And we’re doing that now.

Do you plant ice plant at all?

We do plant some ice plant. But we’re limiting it more and more, with those situations where we need to suppress weeds, we have a fire issue or a real aesthetic need to do it.

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CalTrans estimates that it’s spent $300 million to $500 million on landscaping and irrigation systems since the 1960s. CalTrans maintains 3,300 acres of landscaping throughout the county. That means the agency has spent between $90,000 and $151,000 per landscaped acre.

ROB DAVIS

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