Advanced Mitigation at Mayo Crossings and Potrero Canyon

HRS and parent company Dudek were contracted to complete this design, installation, maintenance, and monitoring project.

Project Facts
  • Newhall Land and Farming
  • Valencia, California
  • Design-Build
  • 49 acres of compensatory mitigation
  • 250,000 native plants installed

The Challenge

Designed to establish 49 acres of cismontane alkali marsh, willow scrub and cottonwood-willow riparian forest adjacent to the Santa Clara River habitat, this project consisted of moving over 200,000 cubic yards of material to create the proper hydrology for establishing these habitats. The existing groundwater table was within 2−4 feet of the surface, and presented many challenges for the grading effort. The high groundwater conditions coupled with unconsolidated native silts and sediments mandated the use of low ground pressure equipment for the excavation and final grading.

The Solution

HRS utilized several dewatering methods including dry sumps, localized French drains, retention basins, and swales. All groundwater was collected and used for dust control and plant establishment irrigation. The excavation and grading portion of construction were completed ahead of schedule with no time extension needed or granted. This project site had several listed and endangered species including; yellow-legged frog, Southwestern pond turtle, willow flycatcher, and plant species calochortus and San Fernando Valley spineflower. After the irrigation was in place, over 250,000 plants were installed throughout the project sites. During the 5-year maintenance phase, HRS is responsible for the irrigation system, weed control, erosion control, trash removal, access control, and remedial actions such as replanting.

In Our Words

“As a Design-Build project, we worked with our design team, Dudek, to find cost-saving solutions for our client – including using yelomine pipe instead of the traditional PVC pipe for the mainline irrigation installation.”

Kevin DiSabatino
President, Senior Construction Project Manager

What We Did

Our restoration expertise provides the right staff and equipment to meet permit requirements.

Project Support

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