Stricter watering rules coming for new projects
By: Bleys W. Rose

A state law limiting lawn and landscaping irrigation takes effect this month, but many Sonoma County jurisdictions are enacting even tougher watering restrictions for future building projects.

Just about every planning department will require a landscape plan if a permit is being issued for new construction or major remodeling, a plan that involves prescribing a water diet for plants, trees and turf.

Starting Friday in unincorporated Sonoma County, any commercial or residential building project larger than 400 square feet can't have a turf area larger than 600 square feet — roughly the size of a 2-car garage — unless a moisture-sensitive irrigation system is installed.

In Santa Rosa, the new “water efficient landscape ordinance” will apply to any project that requires a building permit.

“In the past, you could roll out the sod and call it good,” said Mark Bowers of Landscaping Resource Design in Santa Rosa. “Now, it will require a different mindset, and we are going to be rolling out the mulch.”

In Windsor, grass lawns in front yards are being discouraged under a new ordinance that regulates landscaping by developers in back yards. It applies to any new subdivision of five or more homes.

Rohnert Park, on the other hand, hasn't yet begun considering what rules to include in its landscaping ordinance. City planners said the state's model ordinance is in effect until the city council is able to approve its own.

Government controls on lawn watering stem from the legislature's passage in 2006 of the Water Conservation in Landscaping Act. Its provisions went little noticed until landscapers, developers and government planners began delving into details over the last year.

“What's new is that most new building projects will be on a water allowance,” said Sierra Hart, design director of Allen Land Design, which performed landscape design for Sonoma Mountain Village. “You can still have a lawn and swimming pool, you just have to balance your high water use in one area with low water use elsewhere.”

High water use plants must be grouped in compatible “hydrozones” with separate irrigation valves. And lawn sprayers must be set back two feet from paved areas in order to reduce overspray.

Most ordinances, like the state law, do not legislate types of plants that can be used, but they do prohibit invasive plants that appear on the list of the California Invasive Plant Inventory.

Many also prohibit planting of turf in street medians, traffic islands and areas less than eight feet wide. And mulch must be at least three inches thick when used as ground cover, according to many new ordinances.

The California Department of Water Resources wrote a model ordinance that sets a minimum, which applies to landscaped areas that are over 2,500 square feet in size.

The bill, AB 1881, allows cities and counties to adopt even stricter regulations, and that is the trend in many drought-conscious North Bay jurisdictions.

The law requires that most new homes, many remodels and all commercial, industrial and public agency projects be subject to a “water budget,” which is based on a scientific formula that accounts for water intake and evaporation rates. Although the state law sets the new landscaping water limit at 70 percent of the amount of water required if everything was covered in turf, most cities and the county are going further, setting the bar at 60 percent.

Amy Wingfield, a project planner with the county's Permit Resource Management Department, said many cities are adopting the 60 percent rate (called the evapotranspiration adjustment factor) because of heightened awareness of limited water supply during drought conditions, said Amy Wingfield, a project planner with the county's Permit Resource Management Department.

“We wanted lower thresholds in order to catch landscaping on small lots,” Wingfield said. “And, locally, we do have more rainfall so we felt we could be more restrictive.”