Stream Diversion at the Johnston Ranch – Near Half Moon Bay, San Mateo County

Crop land at the Johnston Ranch

Issue:  The Peninsula Open Space Trust (POST) owns a ranch, which they lease to a grower who raises pumpkins and other vegetables that require irrigation. The historic water source has been a stream diversion on the Arroyo Leon that traverses the ranch. POST proposed to relocate the stream diversion downstream from the historic diversion to an area where reduced impacts would occur. However, POST was informed by the State Water Resources Control Board (SWRCB) that an environmental Initial Study (as required by the California Environmental Quality Act) would have to be prepared to allow the relocation. SWRCB did not have the staff resources to prepare the CEQA document.

Solution:  POST hired Cypress Environmental to prepare the CEQA Initial Study. Cypress consulted with staff from SWRCB and California Dept. of Fish and Game to generate an Initial Study and project mitigation measures that were agreeable to POST and the two State agencies. The ranch now has an approved water source from the new stream location. This new location generates substantially fewer environmental impacts than the former diversion location.