SCH Number 2020040064

Project Info

Title

Environmental Addendum/Reevaluation/Revalidation

Description

Environmental Addendum/Reevaluation/Revalidation for minor change in design/scope of work (final design of temporary river diversion to be implemented during construction) and environmental reevaluation limited to the topic of biological resources.Temporary diversion of flow of the San Gabriel River is required to construct the improvements associated with the proposed undertaking. Since the last environmental evaluation, it has been determined that the duration of construction is estimated at 1 year, and that work will be restricted to the dry season, with construction planned from April 15 to October 15. To assure that the proposed undertaking does not reduce the current channel design conveyance capacity or introduce potentially unstable flow conditions during construction, maintenance of 33% of channel design flow [19,800 cubic feet per second (CFS)] will be required from April-May and for the period of September-October. For the summer period (June-August), maintenance of 5% channel design flow (3,000 cfs) is required during temporary river diversion.

5 documents in project