lower meadow, Palo Seco Creek joins Shephard Creek to form Sausal Creek just below Highway 13. Sausal Creek then runs underneath the Montclair Golf Course and reemerges into Dimond Canyon Park.
Dimond Canyon is not an area highly used by mountain bikes, but is heavily used by neighbors, primarily as a place to run dogs off-leash, and unfortunately for the disposal of construction debris and garbage. The Canyon's walls are quite steep and covered primarily with clay. These conditions along with the tenancy of homeowners bordering the canyon to direct their storm water, laced with fertilizer, detergents, and motor oil, into the canyon have led to significant erosion and water quality problems. There is a major slide on the Upper Dimond Canyon Trail just west of the Montclair Golf Course, which is also a serious cause of erosion.
At the trailhead of the Dimond Canyon hiking trail on El Centro Avenue there is a large sign showing the park trail system. In large letters the sign reads "Trail in Creek Bed." A series of check dams have been constructed along the course of the entire stream, preventing fish from traversing the creek and now function as trash racks. Once the creek passes through Dimond Park it is heavily culverted before it drains into the Oakland/Alameda Estuary.
To suggest, as some have, that trail work in Joaquin Miller Park and Dimond
Canyon is killing native trout is blatantly unfair, unscientific, and totally
unsubstantiated. To accuse cyclists for killing off trout is ignoring all
the aforementioned problems and is a transparent attempt by narrow minded
individuals to keep certain users off "their" trails. We trail users
have so much more to gain by focusing on our common interests. At the top
of those common interests is our need and desire for more public lands and
more protection from threats, which seriously degrade the environment. We
should find common ground and work for positive and shared environmental and
recreational goals. Obviously the park problems will not be solved by calling
for a trail to be closed every time someone, somewhere, just doesn't want
to share