I need a Biologist

I own a parcel of land and am in the permitting phase of building a home. An intermittent stream runs through the property. The county is requiring a Biologist define the high water mark for the 25’ easement reference point. The stream bank was artificially built up 20+ years ago by the local water district so the top of the bank is easily defined, this is what we used as the reference in our submitted plans. The County still wants the high water mark to be defined. The property is in Cameron Park, CA.