Case Study: Wildcat Creek, California
Case Study SummaryConsiderations for Using Ecological Restoration: Combining Flood Control and Ecological Restoration
Overall Project Goal: To implement an urban renewal plan to provide flood control, recreational opportunities, environmental quality, and enhanced economic development.
Restoration Techniques and Parameters of Concern: See table below.
---------------Parameter of Concern-------------
Functional Wetlands Elevated Habitat
Attribute Flooding Degradation Temperature Degradation
===================Construct low-flow channel====================
Carry mean flows d d o d
Transport and scour
sediment d d o d
Spread high flows
plain d d o d
===============Plant trees along low-flow channels===============
Provide shade o o d d
Reduce erosion d d o d
Provide food for
organisms o d o d
riffles o o o o
=================Fence and rotate grazing areas=================
growth o d d d
Reduce erosion d d o d
d means that the restoration technique decreases water quality parameter;
ud means that site-specific conditions can dictate increase or decrease in parameter;
o means that the restoration technique has a negligible effect on water quality parameter.
Highlight on Techniques to Address Fine Sediment Loads/High Velocity Flows: Restoration techniques took into account dynamics of sediment transport and flow throughout the watershed. A key component of the project plan was transporting sediment past vulnerable marsh areas to diminish the impact of deposition. A meandering low-flow channel (10- to 15-feet wide) was designed to (1) carry mean flows; (2) scour and transport suspended sediment at higher velocities; and (3) allow high flows to spread onto the flood plains, lose velocity, and deposit sediment. A detention basin was also placed upstream to trap sediments. Trees were planted along banks to provide resistance to erosive forces of flowing water. Additionally, 312 acres of grazing lands were fenced and divided into four pastures. Livestock grazing is rotated through pastures to allow time for regrowth of vegetation, thereby protecting the watershed from soil erosion.
For a more complete project description, including techniques to address additional parameters of concern, refer to Chapter 6.
| Previous Section | Table of Contents | Next Section |