Climate Action Plan - Measure A-2.1

Increase Residential Tree Planting

This measure along with CAP Measure W-1.2 Reduce Outdoor Water Use will require two trees planted per new home built in the unincorporated county as well as strategies put in place onsite to minimize outdoor water use.
  • 2030 Target: Plant 35,146 trees through new residential development
  • 2050 Target: Plant 28,202 trees through new residential development between 2031-2050

Where are we going?

By 2030, the County aims to plant 35,146 trees and an additional 28,202 trees between 2031-2050 at new residential developments in the unincorporated county. On June 24, 2020, the County Board of Supervisors adopted amendments to the Water Conservation in Landscaping Ordinance, and updates to the Water Efficient Landscape Design Manual, and associated water use authorization application materials. The amended ordinance requires two trees for every new home built in the unincorporated county. Water conservation can be achieved by planting drought-tolerant and native trees, and prioritizing plantings in areas served by recycled and/or greywater infrastructure. To increase awareness of these strategies to reduce greenhouse gas emissions from landscaping, model homes in new residential development will also include signage and educational materials on tree planting and carbon sequestration benefits.
In 2022, the County received a National Association of Counties (NACo) Achievement Award (NACo Category: County Resiliency) for the Landscaping Ordinance Update.

How is this measured?

In preparing an amendment to the Water Conservation in Landscaping Ordinance, the County developed data tracking and enforcement mechanisms to calculate greenhouse gas emissions reductions and ensure policy compliance after implementation. This measure applies to new single-family residential projects as defined in the Tree Planting Guidelines found in the Water Efficient Landscape Design Manual. Multi-family residential projects are not required to meet these tree planting requirements.

Why is this important?

During photosynthesis plants take carbon dioxide from the atmosphere and convert it to oxygen and carbon-based plant matter, storing carbon in the soil. As part of the natural carbon cycle, trees store significant amounts of carbon because of their size and longevity while also providing habitat, clean air, beauty, shade, and community well-being. Trees draw greenhouse gas emissions from the atmosphere to sequester carbon within the tree roots, wood, leaves, and soil. As the tree grows, it continues to absorb more carbon adding both habitat benefit and value to a home. In addition, trees can reduce electricity use by providing shade and temperature regulation benefits for residents.