agua hedionda watershed management plan watershed planning group meeting june 5, 2008 carlsbad, ca
TRANSCRIPT
Agua Hedionda Watershed Management Plan
Watershed Planning Group MeetingJune 5, 2008Carlsbad, CA
Agenda Update on LID Research
Preliminary Recommendations for Watershed Management Actions
Implementation
Next Steps
Update on LID Research
Bioretention Bacteria removal significantly better
than swales Likely to need underdrain system, which
increases cost Without irrigation, need drought-tolerant
plants that can also withstand inundation
Recommend sedimentation forebay to reduce risk of clogging
More research needed for proper design in arid environments
Porous Pavement Many different technologies, rapidly
evolving field Potential for some infiltration, even on
poor soils With proper design, may not need
underdrains Frequent vacuum sweeping (e.g.,
annually) needed to maintain effectiveness
Could be used for sidewalks and patios in addition to large non-commercial parking areas.
Cisterns Cisterns have been successfully tested
in CA in demonstration projects Store runoff from rainy season to use
for site irrigation during dry season Applicable for both residential and non-
residential uses Needs further analysis to determine
cost-effectiveness New development – can amortize cost
with mortgage
City of Encinitas, Roadside GrassCrete parking
Courtesy of Arid Solutions, Inc
Porous Pavement
Cistern
Bioretention
Stream Buffers Multiple functions – stream channel
stability, pollutant trapping and uptake, temperature moderation, habitat
Recommended width varies depending on goals30 – 100 feet for pollutant removal100 – 300 feet for habitat/ecosystem
function/wildlife corridorsChannel protection width varies by stream
order – room for channel migration (e.g., 4X bankfull width)
Current CA local buffer ordinances mostly from 50 – 100 feet
Irrigation Estimates of 40-50 inches/yr in CA,
leads to nutrient-rich irrigation return flow
Technologies allow irrigation to be demand-driven
Can use drought-tolerant plants to reduce demand
Irrigation essentially required by CA fire safety lawMaintain a “defensible space” around buildings30 feet minimum “home defense zone”,
vegetation with high moisture content
Preliminary Recommendations for Watershed Management Actions
Actions: New Development Site Management
Basic LID ImplementationReduce site impervious areaSwalesExtended dry detentionStream buffers
Extended Dry Detention
Swale
City of Encinitas, Volleyball Court/ Detention Area
Photograph Courtesy of EOA, Inc.
Stream Buffer
Actions: New Development Site Management
Enhanced LID ImplementationHigh level of effort to reduce site impervious areaDisconnect impervious surfaces where possible,
direct runoff to pervious areas to maximize infiltration
Minimize disturbance of pervious surfacesBioretentionPorous pavementCisterns/water harvesting
Actions: New Development Site Management
Incorporate use of “basic LID” techniques into local codes and ordinances
Track compliance with stormwater management and LID
As requirements increase (e.g. TMDL), consider use of enhanced LID techniques
Test feasibility of porous pavement, cisterns, and bioretention without irrigation
Actions: Preservation
25 properties 386 acres to preserve $38 to $95 million in total acquisition
costs (fee simple acquisition) Average cost: $98,000 to $246,000
per acre
Actions: Preservation
Field evaluation Landowner outreach Compare with cultural resource priorities Identify/secure funding sources Identify/secure stewardship organizations Develop stewardship plan Annual acquisition workshop Update prioritization tool
Actions: Riparian Buffer Restoration
27 properties 129 acres to restore $9.8 to $19 million in total acquisition
and restoration costs Average cost: $76,000 to $147,000
per acre
Actions: Riparian Buffer and Wetland Restoration
Unincorp.Area
Vista
Carlsbad
Oceanside
San Marcos
I-5
I-5
SR-78
SR-78Agua Hedionda Creek
Buena Cre
ek
La Mirada Creek
Little Encinas
Rom
an C
reek
LegendTargeted Buffer Area
Watershed
Subwatersheds
Municipal Boundaries
Freeways
Streams
Buffer Rest. OpportunitiesComposite Score
Low (3.0 - 5.9)
Medium (6.0 - 8.4)
High (8.5 - 9.4)
o 0 0.9 1.80.45Kilometers
0 0.8 1.60.4Miles
Parcel Prioritization for Buffer Restoration, Revised June 2008
NAD_1983_StatePlane_California_VI_FIPS_0406_FeetMap produced 05-30-2008 - Heather Fisher
Buffer Restoration Priorities
Actions: Riparian Buffer Restoration
Field evaluation Landowner outreach Compare with cultural resource priorities Preliminary design and cost estimate Secure needed permits Identify/secure funding sources Identify/secure stewardship organizations Restoration planning and design Develop stewardship plan Annual acquisition workshop Update prioritization tool
Actions: Wetlands Restoration
14 properties 61 acres to restore $4.2 to $13 million in total acquisition
and restoration costs Average cost: $69,000 to $213,000
per acre
Unincorp.Area
Carlsbad
OceansideVista
San Marcos
I-5
I-5
SR-78
SR-78Agua Hedionda Creek
Buena Cre
ek
La Mirada Creek
Little Encinas
Rom
an C
reek
LegendWatershed
Subwatersheds
Municipal Boundaries
Freeways
Water
Streams
Wetland Rest. OpportunitiesComposite Score
Low (2.7 - 5.9)
Medium (6.0 - 7.4)
High (7.5 - 8.7)
o 0 1 20.5Kilometers
0 0.8 1.60.4Miles
Parcel Prioritization for Wetlands Restoration, Revised June 2008
NAD_1983_StatePlane_California_VI_FIPS_0406_FeetMap produced 05-30-2008 - Heather Fisher
Wetlands Restoration Priorities
Actions: Wetlands Restoration Field evaluation Landowner outreach Compare with cultural resource priorities Preliminary design and cost estimate Secure needed permits Identify/secure funding sources Identify/secure stewardship organizations Restoration planning and design Develop stewardship plan Annual acquisition workshop Update prioritization tool
Actions: Stream Restoration
12 reaches to restore 31,500 feet, or 6 miles to restore $9 to $11 million in restoration costs
Actions: Stream Restoration
Unincorp.Area
Vista
Carlsbad
Oceanside
San Marcos
I-5
I-5
SR-78
SR-78Agua Hedionda Creek
Buena Cre
ek
La Mirada Creek
Little Encinas
Rom
an C
reek
LegendWatershed
Subwatersheds
Municipal Boundaries
Freeways
Water
Stream Restoration Opportunities
Streams
o 0 0.9 1.80.45Kilometers
0 0.8 1.60.4Miles
Stream Restoration Opportunities, Revised June 2008
NAD_1983_StatePlane_California_VI_FIPS_0406_FeetMap produced 05-30-2008 - Heather Fisher
Stream Restoration Opportunities
Actions: Stream Restoration Landowner outreach Compare with cultural resource priorities Preliminary design and cost estimate Secure needed permits Identify/secure funding sources Identify/secure stewardship organizations Restoration planning and design Develop stewardship plan Annual acquisition workshop Update prioritization tool; coordinate with sewer
and storm drain infrastructure programs
Actions: BMP Retrofit
2,870 acres of high priority parcels Located in high priority subbasins based
on existing runoff and loading Five retrofit demonstration sites
(coincident with stream restoration sites) Demonstration BMPs include dry
detention, bioswale, rainwater harvesting, permeable pavement, media filters, trash traps
Actions: Riparian Buffer and Wetland Restoration
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Unincorp.Area
Vista
Carlsbad
Oceanside
San Marcos
I-5
I-5
SR-78
SR-78Agua Hedionda Creek
Buena Cre
ek
La Mirada Creek
Little Encinas
Rom
an C
reek
LegendPriority Subwaterseds
Priority Untreated Parcels
^ Demonstrations BMPs
Subwatersheds
Municipal Boundaries
Water
Freeways
Streams
o 0 0.9 1.80.45Kilometers
0 0.8 1.60.4Miles
Priority BMP Retrofit Opportunities
NAD_1983_StatePlane_California_VI_FIPS_0406_FeetMap produced 05-30-2008
BMP Retrofit Opportunities
Actions: BMP Retrofit for 5 Demonstration Sites
Landowner outreach Preliminary design and cost estimate Secure needed permits Identify/secure funding sources Final planning and design
Actions: BMP Retrofit for Untreated Parcels
Site selection and BMP feasibility Landowner outreach Design and costing Secure needed permits Secure funding
Actions: Monitoring and Enforcement
Long-term stream and lagoon monitoring Long-term wetlands monitoring Inspections/maintenance of sanitary
sewer Inspections/maintenance of storm
drainage system Construction site inspection Stormwater BMP Inspection Tracking Watershed Indicators
Actions: Citizen Stewardship/Public Outreach
Collaborative Watershed Council Education of local boards to gain
support for watershed management Development of citizen education
materials LID workshops and training Annual awards program Management partnerships
Actions: Sustained Funding and Support
Secure grants SWRCB (Prop 84); DWR (Prop 84 and 1e); County IRWM
(Prop 84); EPA 319(h)
Coordinate with partner agencies Wetland Recovery Project; Wildlife Agencies; MSCP/MHCP
programs; Channel Maintenance Programs
Mitigation programs Mitigation Banks; Individual Project Mitigation Needs
Watershed Council Support Wetland Recovery Project; Department of Conservation;
Local Jurisdictions; Local Businesses
Implementation
Your advice needed
Potential funding sources Responsible group(s) General timelines
See handout
Next Steps
Next Steps
June 9-16 - Review of Draft Implementation Table
June 12-16 – Review of Focus Area Recommendations
July 10 – Draft Watershed Management Plan
July 17- Final WPG Meeting to comment on Draft Plan