Biology Reference
In-Depth Information
ecosystem coequal to the goal of creating a more reliable water supply for
California. Then 2009 biological opinions about what should be done to
save endangered smelt and salmon—issued by U.S. Fish and Wildlife Ser-
vice and the National Marine Fisheries Service—called for the restoration
of 8,000 acres of intertidal and subtidal habitats in the delta and Suisun
Marsh. And a new delta stewardship council will for the first time have
land use permitting authority.
Despite the focus on physical habitat in the 1990s and 2000s, CALFED
and other concerned stakeholders also made some effort during this pe-
riod to put more water into the watershed's creeks and rivers to benefit fish
and the ecosystem, and to conserve water so that more might be available
for this purpose.
Restoring a river, or even a creek, is not as easy as breaching a dike to con-
vert a salt pond back into a wetland. The biggest obstacles standing in the
way of restoration on 95 percent of the watershed's rivers and creeks are
dams. While dams may help farms and cities collect water, they also with-
hold essential ingredients rivers need to build fish and forest habitats.
“If there is a deficit in people's understanding of creeks and rivers, it is
that they have two jobs: to transport water and to transport sediment,”
says Christopher Richard of the Oakland Museum.
Other obstacles to restoration are the levees and riprap lining river-
banks and the homes and farms standing in old floodplains. Controlling
rivers via engineering may not be sustainable, according to restoration en-
gineer Philip Williams. Levees continue to fail, floods continue to swamp
homes, and dams never seem to be able to store enough water to slake
California's thirst. Young trees are not growing up to replace old ones
along riverbanks, and the new hatchery-raised salmon are not as resilient
as their wild cousins.
“The hardest question, if we commit to restoring our rivers, will not be
how to do it, but how long to continue investing resources in perpetuating
obsolete river engineering works that prevent us from managing rivers in
a way that allows them to restore themselves, ” said Williams in a 2003
article in CALFED's
Science Action
.
Healthy rivers and creeks need room to move and meander, areas to
flood, and vegetation along their banks. They need gravel added below
their dams and adequate flows to distribute that gravel downstream.
Garden-variety gravel may not be good enough, either, because it won't
smell right to salmon. Indeed, salmon may not use a gravel bed until it has
