It is widely accepted that 95 percent of the Delta’s historic tidal marsh habitat was lost with the development of the Delta’s complex levee system.

marsh loss map
Map source: USGS 

Development and increasing demand on Delta resources has a profound impact on natural habitat and continues to have lasting effects today. This increase in human activity has clearly accelerated natural changes in the Delta and will continue to increase pressure on the estuary in the future. With only 5 percent of native habitat remaining, native fish and wildlife populations are struggling.

Urban growth in and around the region in particular can have dramatic effects on the estuary.  Not only is habitat altered to accommodate growing communities, but the quality of that habitat is polluted as populations in the region increase.

Higher populations lead to higher pollution through storm water runoff of toxic materials, and municipal waste water and industrial discharges are flushed to the estuary by the growing communities and cities in the region.