Using the Past to Understand the Present Emerging Lessons for Environmental Planning in the Santa Clara Valley

Transcription

1 Using the Past to Understand the Present Emerging Lessons for Environmental Planning in the Santa Clara Valley Robin Grossinger Director of the Historical Ecology Program San Francisco Estuary Institute May 3,

2 Restoring the Valley What could be done within the urban context? Coyote Creek Historical Ecology Study: Historical Conditions, Landscape Change, and Restoration Opportunity What would a long-term plan look like? 2

3 Part of coordinated Santa Clara Valley/South Bay effort South Bay Baylands ( ) Guadalupe, West Valley, Lower Peninsula watersheds (2004, ) Coyote Creek ( ) South Santa Clara Cty/North San Benito Cty ( ) Partners: Santa Clara Valley Water District Silicon Valley Pollution Prevention Center USEPA Region IX City of San Jose Santa Clara Valley Urban Runoff Pollution Prevention Program Santa Clara University Environmental Studies Institute Oakland Museum of California The Nature Conservancy Thanks: George Fowler Marc Klemencic Zhen Shao Kevin Sibley Sarah Young Trish Mulvey Chuck Striplen Ruth Askevold Rob Leidy Historical information: Is not gospel Does not reveal the future Does help understand the contemporary landscape Enables an understanding of change Reveals options for the future -- restoration opportunities -- system constraints better understanding of how the system is functioning (hydrology, geomorphology, and ecology) basis for integrated watershed planning 3

4 The Historical Record: synthesizing historical data into useful information Explorer s Journals November 26, 1774: We came to a large river channel, thickly grown with cottonwoods, sycamores, and willows, but without water Mexican Land Grant Documents Mexican Land Grant Documents Courtesy Bancroft Library Courtesy Bancroft Library Early American Surveys Landscape Photography Courtesy Santa Clara County Surveyors Office Courtesy Bancroft Library

5 Early Aerial Photography Historical Landscape Patterns: the natural heritage and diversity of the Santa Clara Valley Lower Coyote Creek ca

6 Coyote Creek ca north of Narrows Laguna Seca: 1916 Valley Oak Savanna: Can the signature habitat of the Santa Clara Valley persist within the urban context? A sampling of oak accounts: A very beautiful plain full of oaks (Font 1776) beautiful groves and clusters of oaks, cypresses, and sycamores, as picturesquely disposed as if planted by the hand of a skillful landscape gardener. (Bartlett 1854) the scattered oak trees and groves afford tasteful sites for residences. (Thompson 1857) 6

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8 2002 Expansion of drainage density: 1800 effects on hydrograph, channel stability, groundwater recharge, riparian habitat 8

9 2005 unconsolidated groundwater recharge basin Disconnect streams where you can Distributed retention of stormwater (infiltration versus drainage) may help explain channel instability and sediment removal 9

10 Recognizing Native Riparian Habitat: And Habitat Conversion A valley, ten miles wide, through the center of which winds the dry bed of a winter stream, whose course is marked with groups of giant sycamores, their trunks gleaming like silver through masses of glossy foliage (Taylor ca 1850 in Carroll 1903: 185). 10

11 Coyote Creek Diversion Canal Freshwater Wetland Restoration: identifying sustainable sites 11

12 Courtesy Santa Clara Valley Water District Courtesy Santa Clara Valley Water District 12

13 Courtesy Santa Clara Valley Water District 13

14 Conclusions: The opportunities are there. A significant portion of the Valley s natural heritage could be re-integrated within the urban framework Geography matters. Restoration/preservation opportunities can be found by understanding historical landscape patterns and where they have changed, or stayed the same Planning will be essential. Coordinated activities towards a shared goal Historical Ecology tools will be available. Useful for GIS overlays, defining planning zones, public communication 14

15 March 7, 2006 Courtesy Paul Amato Brackish sloughwet meadow complex alkali meadow Wetland restoration Restore native mosaics and gradients Endangered species In concert with system s natural tendencies Undeveloped stream benches Floodplain restoration Natural flood protection wet meadowfreshwater marsh-perennial pond complex 15

16 Restore distributary systems Floodplain restoration Natural flood protection Enhance/restore intermittent, Sycamore alluvial woodland stream habitat Rare riparian habitat Less summer water cost? Outer and Middle Bair Island circa