This structure provides a hydrologic connection between the San Francisco Bay and the Alameda Lagoons. On the bay side, the outfall culvert is covered by a pedestrian pier that juts out into the bay. A portion of the gravity fed mechanism used to raise and lower the lagoons is located on the lagoon side between 2811 Bayview Drive and 2813 Bayview Drive - there is no public access to view the mechanism.
As of 2019, according to the Alameda City Manager's Climate Action and Resiliency Plan, the weir and outfall are in need of repair.1
The weir and outfall were a possible source for a "toxic spill" in the winter of 2014/2015.2