Jones Tract

Jones Tract
Name	Jones Tract
Location	Sacramento–San Joaquin River Delta, San Joaquin County, California, California
Coordinates	37°54′N 121°31′W
Area acres	14,500
Country	United States
State	California
County	San Joaquin County, California

Jones Tract is an island in the Sacramento–San Joaquin River Delta of California, located in San Joaquin County, California between the Sacramento River and the San Joaquin River. The tract lies near other Delta islands such as Bethel Island, Twitchell Island, and Mandeville Island, and is used for agricultural production, flood control, and water conveyance. Jones Tract has been a focal point for Delta levee management, interdisciplinary research, and high-profile flood events that influenced state and federal policy.

Geography

Jones Tract is situated in the inland estuary formed by the confluence of the Sacramento River and the San Joaquin River, within the broader San Francisco Bay Area watershed. The island is bounded by channels and sloughs including the Old River (California), Middle River (California), and Three Mile Slough. Its topography is characteristic of reclaimed peatlands—flat, low-elevation terrain protected by an earthen levee ring originally constructed in the 19th and early 20th centuries. Neighboring geographic and administrative entities include Stockton, California, Contra Costa County, and Delta Mendota Canal infrastructure. The tract’s location places it within the jurisdictional networks of Reclamation Districts, California Department of Water Resources, and United States Army Corps of Engineers project areas.

History

The land that became Jones Tract was transformed during the era of California land reclamation involving investors and entrepreneurs active after the California Gold Rush and during the Central Valley development period. Early levee construction and agricultural conversion paralleled projects on Twitchell Island and Sherman Island (California). Over the 20th century Jones Tract supported crops common to the Delta agricultural complex, intersecting with transportation links like the Central Pacific Railroad corridor and regional markets in San Francisco and Oakland, California. Federal and state policy episodes—such as initiatives tied to the Central Valley Project and regulatory frameworks influenced by the California State Water Project—shaped infrastructure investments and land management on the tract.

Delta Subsidence and Flooding

Reclaimed peat soils on Jones Tract experienced progressive subsidence driven by oxidation processes documented across the Sacramento–San Joaquin River Delta and comparable to conditions on Twitchell Island and Frank's Tract. Subsidence increased flood risk by lowering ground elevations relative to surrounding water surfaces, a dynamic examined by researchers at institutions including University of California, Davis and Lawrence Berkeley National Laboratory. A major breach in August 2004 resulted in catastrophic island inundation requiring response from United States Army Corps of Engineers, Federal Emergency Management Agency, and local reclamation entities. That event prompted emergency pumping, levee repair efforts involving contractors and equipment mobilized from San Francisco Bay ports, and follow-on policy reviews by the California Department of Water Resources and Delta Stewardship Council.

Hydrology and Water Management

Hydrologic dynamics around the tract are influenced by tidal exchange, freshwater inflow from the Sacramento River and San Joaquin River, and freshwater exports through facilities linked to the State Water Project and Central Valley Project. Channels adjacent to the island form part of conveyance routes used by the Contra Costa Water District and Metropolitan Water District of Southern California in regional water allocation systems. Pumping and drainage operations historically relied on steam and diesel pumping plants before transitioning to electric pumps overseen by local Reclamation Districts and regulated by agencies such as the California State Water Resources Control Board. Flood management strategies affecting the tract intersect with ecosystem restoration planning by the Bay-Delta Conservation Plan and regulatory actions under statutes like the Endangered Species Act when operations affect listed species.

Ecology and Wildlife

Jones Tract’s conversion from tidal marsh to agricultural peatland altered habitat for species associated with the San Francisco Bay-Delta estuary, including anadromous fishes such as Delta smelt and Chinook salmon, as well as waterfowl and wetland-dependent birds tracked by organizations like the California Department of Fish and Wildlife and Audubon Society. Surrounding sloughs support estuarine assemblages that include nonnative and native aquatic plants and invertebrates monitored by researchers at Scripps Institution of Oceanography and National Oceanic and Atmospheric Administration. Conservation and restoration initiatives in the Delta—including projects coordinated by the California Department of Fish and Wildlife and the U.S. Fish and Wildlife Service—consider trade-offs between levee maintenance, agricultural use, and re-establishing tidal wetlands for species such as Sacramento splittail.

Infrastructure and Land Use

Land use on the tract is dominated by agriculture—row crops, pasture, and seasonal operations—managed under the oversight of local entities like Reclamation District 1667 and influenced by markets centered in San Joaquin County, California and the San Francisco Bay Area. Transportation infrastructure linking the island to regional networks includes county roads, barge access via Delta channels, and proximity to rail and port facilities serving Stockton, California and Oakland, California. Key infrastructure concerns include levee integrity, pumping plants, and utility corridors involving providers such as Pacific Gas and Electric Company and regional telecommunications networks. Post-2004 rehabilitation efforts involved engineering firms, contractors, and funding mechanisms coordinated among United States Army Corps of Engineers, California Department of Water Resources, local reclamation districts, and federal emergency programs.

Category:Sacramento–San Joaquin River Delta Category:Islands of San Joaquin County, California