Stream Protection for the city of Los Angeles A Discussion Fall 2009
Streams? What streams?
In Council District 2 Photo: Jessica Hall La Tuna Canyon
In Council District 3 Photo: Jessica Hall Bell Creek
In Council District 3 Photo: Jessica Hall Dayton Creek at Orcutt Ranch
In Council District 4 Photos: Jessica Hall in Hollywood Hills in Los Feliz
In Council District 5 Photo: Jessica Hall From the UCLA Geography Fairchild Air Photography Collection Flight #H-73 11/29/1929 Stone Creek
In Council District 5 GoogleEarth Photos: G. Haines Hoag Canyon
In Council District 11 Photo: Jessica Hall In Brentwood, near Wilshire
In Council District 11 Photo: Natural Channel Design Bundy Creek
In Council District 12 Photo: Natural Channel Design Brown’s Canyon
In Council District 12 Photo: Natural Channel Design Limekiln Creek Photo: Natural Channel Design
In Council District 14 Photos: Jessica Hall in Lincoln Heights
In Council District 15 Photo: Natural Channel Design At Peck Park, San Pedro
In Council District 15 Photo: Jessica Hall The Bixby Slough/Wilmington Drain
gone In Council District 1 Arroyo de las Pasas From the UCLA Geography Fairchild Air Photography Collection
gone In Council District 1 Arroyo de las Pasas From the UCLA Geography Fairchild Air Photography Collection
gone In Council District 9 From the Los Angeles Public Library Compton Creek
gone In Council District 10 From the Los Angeles Public Library Ballona Creek
gone In Council District 10 Arroyo La Brea
In Council District 13 gone “Forty -five acres of ground, now a waste…will be reclaimed for use - when this slough...is filled in. The live stream of this creek now flows through the Sacatela No. 3 storm drain, leaving no excuse for the gullies and ravine which now exist.” - Los Angeles Times, 1930 Courtesy Eco-Village From the Los Angeles Public Library Sacatela Creek
Throughout LA City The norm
Historic Streams in Early 20 th Century Streams Los Angeles area Dry Wash 94 miles Intermittent 312 miles Perennial 148 miles Wetlands 9 sq. miles Over 90% loss of streams & wetlands Map: Jessica Hall
Natural streams work for us - for free! Stream functions Benefits building materials soil fertility biodiversity & habitat sediment transport replenish beaches groundwater recharge economic welfare drinking water flood storage water quality stormwater conveyance carbon sequestration flood protection habitat recreation microclimate property values Image: Jessica Hall
Types of Streams Ephemeral Streams Intermittent & Perennial Streams Photo: Jessica Hall Photo: Jessica Hall Caballero Creek, CD 3 Caballero Creek, CD 3 Usually wet or moist Usually look dry Runs year round or part of year Only have water during rainy season Most people’s idea of a stream Important for water quality, recharge & habitat
Parts of a stream Streams have one or more channels, a floodplain and terraces. HIGH LOW TERRACE: TERRACE : Infrequently flooded Rarely flooded Slide data from Stream Assessment & Restoration Design Workshop, GEOMORPHIC by Tom Moody, PE, FLOODPLAIN: Natural Commonly Channel flooded Design, Inc. CHANNEL: Carries low flows; bedload sediment Aliso Creek, CD 12 Photo: Natural Channel Design
Natural Streams Protect Water Quality Streamside plants and organisms remove and break down pollutants like nitrogen and total suspended solids. Wonderland Creek, CD 5 Photo: Jessica Hall
Natural streams support biodiversity LA lost its salmonids with channelization of LA and San Gabriel Rivers. West Coast commercial salmon fishery at point of collapse. Maintaining local fisheries maintains food security. And biodiversity supports you and me. Photo: Jessica Hall
Loss of streams = loss of habitat Mandeville Canyon, CD 11 Photos courtesy Wendy Sue Rosen
Loss of streams = extinctions http://www.geocities.com/royvandeho ek/losangelessunflower.htm Helianthus nuttallii parishii Los Angeles Sunflower Potentilla multijuga Ballona Cinquefoil
Courtesy Pasadena Museum of History streams are human habitat Arroyo Seco 1885
streams are human habitat Photo: Jessica Hall
Protected floodplains protects property Floodplain After Filling Slide from: No Adverse Impact, Association of State Floodplain Managers
Protected floodplains reduce liability Slide from: No Adverse Impact, Association of State Floodplain Managers
Protecting floodplains reduce liability The City of Los Angeles is also obligated to prevent increases in flood peaks and stream velocities under its MS-4 Permit. as measured by: • increased flood peaks & flood stage • flood velocity • erosion and sedimentation Slide from: No Adverse Impact, Association of State Floodplain Managers
Protecting streams enhances property values Stream Buffer Benefits: Provide Economic Value • Minimizes Flood Mitigation • Increases Property Values – $10,000 or more in Virginia (Tippett et al., 1999) – Values of Homes Increase as far as 3 Blocks from the Stream (Vince Graham, ION Development) – Property Values 32% Higher for Locations Adjacent to a Greenbelt Buffer in Boulder, Colorado (Correll et al. 1978). • Increases Tourism Slide content from: Stream Setbacks and Buffers: Adding Value to Your Community through Stormwater and Natural Resource Conservation, for the Johnson County Stormwater Management Program & Mid-America Regional Council, By: Black & Veatch, Inc., Tetra Tech EMI, and Patti Banks Associates.
Protecting streams enhances property values $150,000 $175,000 $195,000 $195,000 Slide content from: Stream Setbacks and Buffers: Adding Value to Your Community through Stormwater and Natural Resource Conservation, for the Johnson County Stormwater Management Program & Mid-America Regional Council, By: Black & Veatch, Inc., Tetra Tech EMI, and Patti Banks Associates.
Managing streams Not all streams are mapped accurately Photos: Guangyu Wang Arroyo del Jardin de los Flores, CD 4
Managing streams State and Federal laws do not stop streams from being destroyed. Map and Aerial: Microsoft Terraserver 1976. Kenter Creek, CD 11. 2004. Kenter Creek, CD 11 CEQA and the Clean Water Act require mitigation not protection for filling a stream.
Managing streams State and Federal laws do not stop streams from being destroyed. Photo: Jessica Hall Creek in the Los Angeles River headwaters (CD 12) at risk. Whoever bought this creek can legally fill it or line it in concrete.
Managing streams Local jurisdictions should be the front lines of stream protection. ISSUES RESULTS • Stream originally “unmapped” Erosion • Grading in Sedimentation streambed • Construction to Bank instability edge of banks • Check dams and Poor water quality other construction in stream channel Habitat loss • No stream buffer • Diversion of flows Photo: Jessica Hall Kenter Creek, CD 11
Managing streams Local jurisdictions should be the front lines of stream protection. Photos: Jessica Hall Stone Canyon Creek, CD 5 June 4, 2006 Whoever bought this creek can legally fill it or line it in concrete.
Managing streams Protecting streams costs less than restoring them $900/linear foot Dry Canyon Creek - $500k $2,800/linear foot Las Virgenes Creek - $1.5 m
Stream protection: mapping & city Plan Check •Adding City streams to Navigate LA •Creating a Stream Identification Zone •Ensuring plan check includes consultations with: California Department of Fish & Game US Army Corps of Engineers Photo: Jessica Hall Regional Water Quality Atwater Creek, CD 4 Control Board
Stream protection: using buffer zones Buffer Architecture • Three-zone buffer is preferred • Progressive zones allow more intensive uses • 100 foot minimum recommended • Johnson County Model: – Streamside zone (25 ft.) – Middle zone (50 ft.) – Outer zone (25 ft.) Slide content from: Stream Setbacks and Buffers: Adding Value to Your Community through Stormwater and Natural Resource Conservation, for the Johnson County Stormwater Management Program & Mid-America Regional Council, By: Black & Veatch, Inc., Tetra Tech EMI, and Patti Banks Associates.
Stream protection: using buffer zones Variations on the Theme • Shawnee, Kansas: – Two zone buffer – 25-yr floodplain plus 90 feet – No habitable structures allowed within buffer • Liberty, Missouri (tentative): – Either 100 feet top-of-bank or 100-yr floodplain, whichever is greater – Uses within buffer may be limited to recreational trails Slide content from: Stream Setbacks and Buffers: Adding Value to Your Community through Stormwater and Natural Resource Conservation, for the Johnson County Stormwater Management Program & Mid-America Regional Council, By: Black & Veatch, Inc., Tetra Tech EMI, and Patti Banks Associates.
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