A few answers from the FAQ on section 7 consultations on the FWS website are quoted below .

Reading this I'm guessing that Contra Costa County Water District is playing the role of 'designated non-Federal entity' who has requested a consultation. There's no specific time frame on FWS responding to that, so I'm going to make some calls to try and find out what is going on.

If, as will certainly be the case here, FWS says there are red legged frogs and tiger salamanders that could be adversely affected by DFG trout stocks, then they have to do a "formal consultation" which can take up to 135 days, not counting any time going back and forth if the "package" of information sent to FWS is not complete.

What steps are involved in a section 7 consultation?

The Federal agency, or the applicant as the designated non-Federal entity, contacts the appropriate local Service office to determine if listed species are present within the action area. The Service responds to the request by providing a list of species that are known to occur or may occur in the vicinity; if the Service provides a negative response, no further consultation is required unless the scope or nature of the project is altered or new information indicates that listed species may be affected.

If listed species are present, the Federal agency must determine if the action may affect them. A may affect determination includes those actions that are not likely to adversely affect as well as likely to adversely affect listed species. If the Federal agency determines that the action is not likely to adversely affect listed species (e.g., the effects are beneficial, insignificant, or discountable), and the Service agrees with that determination, the Service provides concurrence in writing and no further consultation is required.

If the Federal agency determines that the action is likely to adversely affect listed species, then it must request initiation of formal consultation. This request is made in writing to the Services, and includes a complete initiation package. Up to that point, interactions have been conducted as informal consultation; however, once a request for formal consultation is received, the process becomes formal, and specific timeframes come into play. Formal consultation is initiated on the date the package is received, unless the initiation package is incomplete. If the package is incomplete, the Service notifies the Federal agency of the deficiencies. If a complete package is submitted, the Service should provide written acknowledgment of the request within 30 working days. This written acknowledgment is not mandatory, but is encouraged so that there is documentation in the administrative record that formal consultation has been initiated.

From the date that formal consultation is initiated, the Service is allowed 90 days to consult with the agency and applicant (if any) and 45 days to prepare and submit a biological opinion; thus, a biological opinion is submitted to the Federal agency within 135 days of initiating formal consultation. The 90-day consultation period can be extended by mutual agreement of the Federal agency and the Service; however, if an applicant is involved the consultation period cannot be extended more than 60 days without the consent of the applicant. The extension should not be indefinite, and a schedule for completion should be specified.

What are the potential outcomes of a biological opinion?
The biological opinion is the document that states the opinion of the Service as to whether or not the Federal action is likely to jeopardize the continued existence of listed species or result in the destruction or adverse modification of critical habitat.