Santa Clara River Deposition Suitability Analysis

PACE developed a deposition suitability analysis for Newhall Ranch in GIS to determine the best potential locations to deposit sediment within the River. Newhall Ranch is the largest master planned communities located in Los Angeles County, and straddles a major river named the Santa Clara River.  The Ranch needed to find suitable locations for sedimentation deposition within the Santa Clara River reach within the project boundary.    PACE GIS worked with the engineers to determine which conditions would be best suited to absorb the new sedimentation.  First the areas would be prioritized by the amount of degradation our analysis has shown we predict to occur.  The higher amounts of degradation or soil lost would hold priority over the smaller degradation values.  Next, the area chosen would have to be within one of the six storm event floodplains prepared and analyzed by PACE.  These storm events include 2, 5, 10, 20, 50 and 100 year storm events.  The highest priority would be given to the lower storm events with the thought the higher frequency would be used to wash the sedimentation downstream.  Lastly, the deposition had to be outside of sensitive habitat located within the River.  PACE prepared a model using Model Builder in ArcGIS to calculate which locations will have the best potential to locate the new sediment.  The analysis results were mapped showing locations from poor to ideal within the River reach.

Software:

• ArcGIS
• Spatial Analyst
• Model Builder
• Python