Post on 17-Dec-2015
transcript
Paying for TMDL Compliance – Different Approaches From Around Southern California
Southern California Water Dialogue GroupFebruary 28, 2007
Irvine Ranch Water District
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Outline of Today’s Discussion
• IRWD’s Approach to Integrated Water Resources Planning and Management at the Watershed Level
• Unique TMDL Compliance Funding Mechanisms and Strategies
• Future Opportunities for Water Supply Entities and Cities
Irvine Ranch Water District
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About Irvine Ranch Water District• Formed in 1961 by landowners to supply water for extensive irrigation
- population 300
• California Water District providing:- Water - Hydroelectric- Wastewater - Recycled water - Resource management - Urban runoff management / control
(Modified enabling act in 2000)
• Current Customer Base- Residential Population 325,000- Daytime Population estimated 500,000- Service Connections 93,000
• Size of District - 179 square miles/114,500 acres- 118 square miles in San Diego Creek
watershed
Irvine Ranch Water District
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• Approximately coincident with IRWD service area (80% of watershed in IRWD)
• Primary freshwater source for Newport Bay—EPA “impaired water body”
• 118 square miles
• City of Irvine and portions of:– City of Lake Forest– City of Newport Beach– City of Orange– City of Tustin– Unincorporated County
• 4 primary types of TMDL’s:– Nutrients (nitrogen/phosphorous)– Sediment– Pathogens– Toxics (pesticides, selenium, etc.)
TMDL Compliance - San Diego Creek Watershed
Irvine Ranch Water District
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Relationship Between Water Consumption and Dry Weather Flow Generation
Discharge into sensitive receiving waters
Dry weather runoff that carries pollutants =
Over-irrigation =
Example: Urban Runoff in San Diego Creek
• Implementing a “Cradle to Grave” philosophy
• Both multiple and single entity approaches
Irvine Ranch Water District
6*Source: Northwood (Irvine) Residential Runoff Reduction Study, 2003
Urban Runoff Generation – Residential*
SFD5,000 FT
Lot62%8,000
AF
Runoff10%1,290
AFET & I28%
3,610 AF1,150,000GallonsPer Day
12,900AF/YR
AverageO.C. Water
Agency/Dept
30 agencies/depts.
Irvine Ranch Water District
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Urban Runoff and TMDL Compliance Partnerships – Where Does IRWD Fit?
Santa Ana Regional Water Quality Control Board (Region 8)
County of OrangePrincipal Permitee
Lake ForestCity Co-Permitee
Newport BeachCity Co-Permitee
OrangeCity Co-Permitee
TustinCity Co-Permitee
IrvineCity Co-Permitee
Permittee Compliance Mechanisms•Education/Training/ Inspections•Development/Construction Standards•Water Quality Monitoring•Local structural BMP’s•Runoff management and Source Control (Conservation and demand management)•Watershed-wide Treatment BMP’s
IRWD’sTMDL Management
Strategies
Irvine Ranch Water District
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Urban Runoff Management and Source Control Strategy #1:
Water Conservation and Demand Management
TMDL Compliance Strategies
Irvine Ranch Water District
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Allocation-Based “Conservation” Rate Structure
Basic Premise:
• Allocate water to customers based upon land use-specific indoor uses and landscaping needs
• Encourage use within allocation through a significantly tiered commodity pricing system
• Over-use generates “penalty” revenue to fund TMDL Compliance Activities:
– Source Control (water conservation programs, incentives and education)
– Urban runoff treatment
Irvine Ranch Water District
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TIER BREAK POINT RATE (% of Allocation) ($/ccf)
Low Volume 0 - 40% $0.75Base 41-100% Base rate $0.91Inefficient 101-150% 2x base $1.82Excessive 151-200% 4x base $3.64Wasteful 201+% 8x base $7.28
100% of water needed for indoor/ outdoor uses
Typical Residential Fixed Charge = $6.75/month (3/4” meter)
Allocation-Based Rate Structure
Irvine Ranch Water District
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Sample Residential Water Billing - Overuse
8/10/06 9/09/06 1255 1337 82 CCF
USAGE - LOW VOLUME DISCOUNT 16 0.75 $12.00
USAGE - CONSERVATION BASE RATE 23 0.91 $20.93
USAGE - INEFFICIENT 20 1.82 $36.40
USAGE - EXCESSIVE 19 3.64 $69.18
USAGE - WASTEFUL 4 7.28 $29.12
WATER SERVICE CHARGE $6.75
YOUR ALLOCATION FOR THIS BILL 39 CCF
BILL CALCULATION BASED ON 0.12 ac. / SFD
TO AVOID LATE CHARGE PAY BEFORE 10/07/06 $174.38
Over allocation use pays penalty rates,
discourages overuse
Commodity Within Allocation $ 32.93 20% Commodity Above Allocation $134.70 80%
Irvine Ranch Water District
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Determining Appropriate Allocations
Single Family Detached House (4 occupants)
Outdoor Allocations• Irrigated area seasonal needs (Eto)
Variances• Pool• Additional occupants• Medical needs• Others (equestrian, etc.)
+
+
Irvine Ranch Water District
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Landscape Allocation
• Allocation based on landscaped area and real time evapotranspiration
– Cool season turf
– Irrigation system efficiency - 80%
• IRWD has three weather stations
Central
Coastal
Foothill
Irvine Ranch Water District
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Results: Rate Structure Reduces Water Use
• Since Rates Adopted in 1991:
– Average water use dropped from 3.5 ft./acre To 1.9 ft./acre
– Stabilization of dry weather runoff
– Changes in plant material selection - more “California Friendly” landscaping
• From 1992 to 2000:
– Irrigated area doubled
– Water use increased by 3%
Irvine Ranch Water District
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Water Conservation – Landscape Programs
• Landscape Water Management Report Card
• “Fall Campaign” (Postcard reminders)
• Residential Education / Workshops
• Protector del Agua Landscape Certification Program
New Programs
• Artificial Turf Replacement
• Weather Based Irrigation Controllers
• “California Friendly” landscaping
Irvine Ranch Water District
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IRWD Residential and Landscape Water Usage
Water Conservation Programs
60
70
80
90
100
110
120
130
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Gallo
ns/C
ap
/Day
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Acre
-Feet P
er
Acre
Avg. Gal/Cap/Day
Avg. AF/Acre
Landscape Water Use
Residential Water Use
Irvine Ranch Water District
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Per Capita Water Consumption Comparison
89
0
20
40
60
80
100
120
140
160
Gal
lon
s P
er C
apit
a P
er D
ay
Source: California Urban Water Conservation Council, 2002
Irvine Ranch Water District
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Urban Runoff Management and Source Control Strategy #2
Watershed-wide Structural BMP’s – the Natural Treatment System
TMDL Compliance Strategies
Irvine Ranch Water District
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San Joaquin Marsh
• 320 ac. owned and managed by IRWD
• 68 ac. of treatment ponds
• 3.5 million gallons per day
• Removes about 70% of
nitrogen from San Diego
Creek (75,000 pounds per
year)
• Removal of 50,000 tons of
sediment and 10,000 pounds
of phosphorus per year from
desilting basins
Newport Harbor
Upper Newport Bay
IRWD Plant(MWRP)
San
Die
go C
reek
UC Natural Reserve
Restored wetlands/uplands
San Joaquin MarshN
Pacific Ocean
CarlsonMarsh
Natural Treatment SystemPonds
Urban Runoff Treatment Systems – Treatment Wetlands
Irvine Ranch Water District
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Natural Treatment System (NTS)
• Expands wetlands treatment watershed-wide
• 71 sites considered; 31 selected
• Completed 4 sites, designed 10 sites, 3 sites construction award 1/2006
• State/federal grant funds authorized (25%)
• Integral with city runoff management programs
• Multiple governmental, private, regulatory and community/envirnomental entity effort
Urban Runoff Treatment Systems
Irvine Ranch Water District
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Complex Multiple Entity Effort - NTS
Inter-agency Agreements for Operating, Maintenance, Facility Use
• Watershed Cities -- Irvine, Lake Forest, Newport Beach, Orange, Tustin
• County of Orange
Regulation, Permitting, MS4 Permit Authorization
• Regional Water Quality Control Board• CDFG, USFWS, Corps,
Supplemental Funding• EPA, USBR, State Water Resources,
Coastal Conservancy
Critical Reviewers and Stakeholders• Residents• Environmental Community Representatives
Development Standards, R/W, Construction• Landowners and developers
Irvine Ranch Water District
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Future Opportunities for Water Supply Entities and Cities
• Water Purveyor recognition of the water supply and environmental management interrelationship
– Embrace a “Cradle to Grave” management and problem solving philosophy
• Clarification of ability to participate in TMDL compliance activities through legislation:
– Add to list of services
– Incentive based participation
(i.e. adopt conservation rate structure, can use revenue for stormwater compliance programs)
Irvine Ranch Water District
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Questions?
Paul D. Jones II
General Manager
Irvine Ranch Water District
jones@irwd.com