For Wetlands Research
Orinda, California

Since 1999, Questa has been providing technical analyses for the Montanera Development Project. We have developed detailed information on the hydrology, geomorphology, and channel hydraulics of a creek system in the Orinda Hills that would be substantially altered by the development of a large residential community and golf course.

The creek is located in steep, landslide-prone terrain; relocation and regrading of the creek to create a stable channel design that retains riparian and aquatic values presented a major challenge. We completed a detailed study of the channel geomorphology, watershed hydrology, and channel hydraulics, including a water balance model, a runoff model, and detailed measurements of channel profile to determine step pool sequence/geometries, bankfull width/depth ratios, stream gradient, and pool/riffle relationships.  The flow monitoring of Brookside and Moraga Creeks quantified annual runoff and sediment transport conditions, developed a rating curve of creek stage versus flow rate, assessed suspended sediment loading, turbidity trends, and bed load transport regimes, and provided calibration data for the watershed hydrologic model.