Background on Cache Creek and Scope of the Presentation - Cache Creek is a central lifeblood of Yolo County. Rising from springs high in the inner coast range, it flows into Clear Lake, through Capay Valley, and eastward on into the Yolo Bypass. For millennia, Patwin Wintun people have lived along the banks of Cache Creek tending the land and utilizing its abundant natural resources.

Before the first white settlers arrived several hundred years ago, the Cache Creek watershed looked very different than it does today. The riparian forest reportedly extended upwards of a mile in each direction from the meandering Creek. This floodplain was nourished by annual high-water events over-flowing the banks of the creek carrying sediment and nutrients onto the riparian forest. This produced an amazing diversity and abundance of plants and animals in this complex ecosystem.

However, settlers began mining the sand and gravel from the Creek bed which gradually deepened the Creek channel. By the 1980s, the bottom of the channel was as much as 30 feet lower in some areas. This deeper channel conveyed the annual floodwaters directly down to the Yolo Bypass rarely over-topping the channel banks and flooding out and onto the adjacent riparian forest as had occurred for countless thousands of years.

In 1996, further in-channel mining on Cache Creek was prohibited by Yolo County and new mining was relegated to off-channel agricultural sites adjacent to the Creek. Typically, in those mined areas the top 15-20 feet of topsoil is removed and stockpiled on site while mining of the underlying sand and gravel proceeds down to depths in excess of 100 ft depending on the depth of the underlying materials. This dramatically lowers the average level of the area after mining completion. County ordinances then require the mining companies to “restore” the land to either i) viable agricultural land of the same quality and productive standard as existed before mining, ii) natural habitat, or iii) deep impoundment pits which are filled by groundwater flow.

Unfortunately, these reclamation processes have produced their own set of problems including i) reclaimed agricultural lands that are less fertile and productive than the original farmland, ii) stunted habitat restoration, and iii) formation and bioaccumulation of toxic methyl mercury in the impoundment pits.

In this seminar, a possible new restoration vision will be discussed that could return these former mined lands to functional floodplains using natural fluvial processes without the attendant shortcomings now seen in the conventional restoration efforts.
_____________________________________

To attend via Zoom

Browser Link: https://us02web.zoom.us/j/83728469614?pwd=GdGDNCNpbZrbxvqbWpfd766v9mI7Sb.1

Meeting ID: 837 2846 9614

Passcode: 186556

Dial by your location

• +1 669 444 9171 US

• +1 669 900 9128 US
_____________________________________

For more information, contact Alan Pryor at [email protected]m or 916-996-4811.
_____________________________________

Disclaimer Required by Yolo County Library - “This event is not sponsored by Yolo County Library and the presence of this group in the meeting room does not constitute Yolo County Library’s endorsement of the policies or beliefs of this group.”