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5. Alternatives for Future Use of the DMMS <br />(periodic material placement, grading, and discing), marsh and upland vegetation would colonize <br />the higher areas of the site, converting unvegetated mudflat areas to vegetated marsh. Higher areas <br />than these would likely be colonized with a mix of native and non-native emergent marsh and <br />upland plant species. In the shallowly flooded areas, a more abundant and permanent invertebrate <br />community could establish and serve as a food source for shorebirds and waterfowl. Overall, habitat <br />quality may increase. <br />The Waste Discharge Requirements (WDR) permit the site for management of dredged material <br />from the San Leandro Harbor "in perpetuity." No abandonment plan has been articulated and it is not <br />known what, if any, requirements the permitting agencies would impose. <br />Operate DMMS for other Harbor Dredging Operations <br />This alternative provides for minimal operations and maintenance (O&M) to preserve the DMMS <br />for potential future use. Although there is currently no known demand to use the DMMS for <br />dredged material handling, demand may increase over time for adaptation to sea level rise (e.g., <br />levee construction and fill along the shoreline as proposed for the Hayward Area Shoreline <br />proiect16). The cost of trucking material from the DMMS could be paid for by others, in which <br />case the City could resume dredging the harbor or allow others to deposit dredged materials at the <br />DMMS. This alternative protects a City asset (the DMMS) that is of low value now, but may <br />become valuable in the future. <br />Under this alternative, the City would continue to disc the site periodically to remove vegetation. <br />The City would maintain the levees and hydraulic structures as needed to preserve the existing <br />site hydrology. The purpose of these O&M activities would be to maintain the site in its current <br />condition. If no O&M were conducted, habitat would develop at the site; regulations protecting <br />this habitat could preclude future use of the site for dredge material storage. <br />Shorebird Habitat Enhancement <br />The Shorebird Habitat Enhancement alternative would create shallow open water and island areas at <br />the site for shorebird foraging, roosting and nesting. Shorebird habitat is considered valuable in <br />San Francisco Bay and is the focus of several large restoration efforts. Shorebird habitat is expected <br />to become scarcer with sea level rise. The concept presented here is based on ESA PWA's designs <br />for similar habitat for the South Bay Salt Pond Restoration Project and the Hamilton Wetland <br />Restoration Project, which both include significant areas of created shorebird habitat. <br />The site could be restored at approximately existing grades or raised to include as much as <br />60,000 CY of new dredged material. The 60,000 CY fill volume assumes that the site is filled to <br />2.5 ft (average of 1 ft of fill over most of the site). The design elevation and amount of fill would <br />depend on tide levels at the adjacent SLSM marshes and Estudillo Channel. The site must be low <br />enough to flood on most high tides. Mean high water (MHW) at the San Leandro Marina is 3.4 ft, <br />16 See http://www.hayward-ca.gov/departments/ced/documents/planning/2010/HASPA%20Report%2Ovl5A%20- <br />%20with%20acknowledgements.pdf <br />San Leandro Marina Harbor Basin 5-4 ESA / 210461 <br />Alternatives Study March 2011 <br />