agua hedionda watershed management plan watershed planning group meeting june 5, 2008 carlsbad, ca

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