This data package is a key deliverable for the Research to Understand Impacts of Bay Sand Mining on Sand Supply and Transport in San Francisco Bay and the Outer Coast project.

This final report presents the sediment budget with sand and mud components separately quantified. Although the focus was on sand, preparing both sand and mud budgets provided a framework for quality assurance since all the mass and volume conversions needed to be reconciled to either add to zero or 100% with no missing mass or volume from the conversions. The sediment budget included terms for inflow and outflow and storage. Inflow terms included the mass loads from the Sacramento and San Joaquin Rivers draining the Central Valley, the small local tributaries that drain the nine counties that surround the Bay, and sand inflow from the Pacific Ocean via littoral processes. Outflow terms included sediment mass associated with sand mining, navigational dredging, wetland deposition due to sea-level rise (SLR), and sediment mass removed from the tidal portions of flood control channels on the edge of the Bay. The change in bathymetry was the only term considered for change and storage; data on the change in beach geometry and volume or the change in sediment storage associated with any net wetland retreat were lacking. The input, output, and storage terms included in the budget were estimated for a 20-year period beginning 2001 and ending 2020. The sand and mud budgets were resolved for each subembayment again, ensuring there was no missing mass; the sum of the sand and mud masses gained and lost from each of the five subembayments needed to sum of the total Bay total sediment. 

The report includes a short 2 page introduction, a detailed 15 page methods section (supported by 9 appendices (maps, tables and diagrams)), and 10 pages of results (including 2 half page figures and 5 full page figures). This is followed by a discussion of uncertainties (including a sensitivity analysis), a discussion of the influence of sand mining on the sediment budget, and a discussion of sediment transport at Bay cross-sections. The report is bounded by an executive summary at the beginning and a conclusions and recommendations section at the end along with a reference list of cited literature.

Subtask Contact: Lester McKee, Senior Environmental Scientist ([email protected]).

File Contents

The data package includes the following input file:
1. Subtask 1.7 Sediment budget synthesis v2.xlsx
This MS Excel file contains the budget numbers for each element of the budget in mass units. It was extracted from a larger file that contains three main worksheets (a volume sheet - for data that were obtained in volume units), a bulk density sheet that provided the conversion factors used between volume and mass, and the mass sheet presented here. The three sheets were linked by formulae. This document is just the summary.