|
Murrieta Creek Flood Control
Environmental Restoration and Recreation Project
|
Flood Control:
The largest known flood in the overall Santa Margarita watershed was
in January of 1862, and the second greatest was in February 1884.
Other major floods occurred in 1916, 1938, 1943, 1969, 1978, 1980,
1991 1992, and 1993. During the 1978 and 1980 events, the U.S. Army
Corps of Engineers staged emergency flood fights, and federal funds
were used to restore sections of the existing Murrieta Creek channel
that were severely eroded. In January and February of 1993, Riverside
County was hit by severe storms resulting in a Presidential Disaster
Proclamation. This large flood event resulted in two to six feet of
sediment deposition in the Murrieta Creek streambed from Winchester
Road south into the "Old Town" area of the city of Temecula. Breakout
of floodwaters was caused largely by the magnitude of the event, the
vegetation density, and sediment accumulations within the channel
that severely reduced flow-carrying capacity. The storm caused over
$10 million in damages to public facilities along Murrieta Creek.
In addition, the Riverside County Flood Control and Water Conservation
District incurred approximately $450,000 and the City of Temecula
and the Kemper Corporation expended in excess of $1 million in flood
clean-up and facility repair costs.
Flooding problems in the Murrieta Creek watershed are related to inadequate capacity
of the existing drainage network, particularly in the "Old Town" area
of Temecula. The problem manifests itself as frequent overtopping
of the Murrieta Creek channel by floodwaters in a number of channel
reaches, flood inundation of structures with attendant damages, and
other water-related problems caused by these events, including emergency
costs, automobile damage, and traffic disruption.
Ecosystem Degradation:
Murrieta Creek has been altered since the late 1800's, and has experienced channelization and some
type of flood control since the 1930's. Restoration along the creek banks, within the channel invert
and in and around its tributaries and floodplain would not only bring back historic habitat functions,
including surface and sub-surface hydrology, but also invite a large array of desired wildlife and plant
species, including sensitive species, while potentially reducing the extent of undesirable exotic species.
The ecological resources of Murrieta Creek and its associated hinterlands have been identified as a resource
of extremely high concern. Several resource agencies, including the U.S. Fish and Wildlife Service and U.S.
Environmental Protection Agency, have stipulated that Murrieta Creek is one of the last high quality minimally
disturbed riverine environments in southern California. These same agencies have indicated that, prior to the
destructive floods of 1993, there was a much higher quality environment associated with the creek in many areas,
particularly downstream of Warm Springs Creek. Although currently a source of contention as to the extent, there
is no doubt that the ecological resources of Murrieta Creek have suffered from the effects of natural flood events
as well as from emergency channel repairs and the on-going channel maintenance which is necessary to provide
sufficient flood control for the cities of Murrieta and Temecula. As a result, there is a significant opportunity
to restore degraded habitat along Murrieta Creek in concert with flood damage reduction measures.
|
|