Primary Production, the amount of tissue generated by photosynthetic organisms (e.g., plants and algae) over time, forms the basis of food webs. The Sacramento-San Joaquin Delta has unusually low primary productivity relative to other estuaries (Cloern et al. 2014, Jassby et al. 2002). Food availability has been identified as one contributor to the multi-stressor problem of pelagic organism decline in the Delta (Baxter et al. 2010). But, the constraints on primary production and the relative importance of different production sources to the food web are major uncertainties in this system. Landscape configuration and hydrodynamics are major drivers of primary production dynamics, and understanding how the extensive historical changes in the Delta’s landscape have altered the system’s potential for supporting wildlife and human populations can inform restoration planning and management across the region. Investigating basics about primary production in the Delta can guide us towards better restoration and management decisions.