pathways to lasting solutions “the longest yard” water budget rate structures & the city of...

Pathways to Lasting Solutions

“The Longest Yard”

Water Budget Rate Structures &

The City of Boulder, ColoradoJanuary 25, 2007

© 2006 Malcolm Pirnie, Inc. All Rights Reserved


Today’s Discussion

Rate Structures in GeneralWater Budget Rate StructuresWater Budgets and the CityDiscussion


What is a Rate Structure?

Typically consists of two componentsService charge

• Fixed charge, Readiness to Serve

• Recover customer billing and metering costs

Volume charge• Unit charge based on amount of water used

• Variety of volumetric rate designs available

The design and organization of billing charges by customer class in order to recover revenue requirements


Uniform Rate


Decreasing Block Rates


Seasonal Rate


Uniform Rate Decreasing Block RatesIncreasing Block Rates


Uniform Rate Decreasing Block RatesWater Budget Rates


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The Rate Structure Continuum

Least MostConservation


Water Budget Rates Designed for resource efficiency Budget individualized for each customer’s

indoor usage and outdoor usage Retains increasing block structure Volumetric block thresholds dependent on

customer’s usage patternsIndoor allowanceOutdoor allowance


Water Budget Rate Components Indoor allowance

People per householdBuilding square footageNumber of bedrooms/bathrooms

Outdoor allowanceIrrigable areaLot square footageWeather considerations, evapotranspiration


City of Boulder Water Budget Rates Drought of 2002 - 2003 Mandatory water restrictions instituted Goal:

Reduce water use by 25 percent, or 1.19 million gallons between May 2002 and April 2003

Goal met by November 2002 when 1.296 million gallons was conserved


City of Boulder Water Budget Rates Water restriction prompted Citizen involvement

More flexibility during drought (when and how much)Preferred to know specific quantity of water neededMore education

City began investigating alternative rate structures in June 2003Hired consultant to review various structures Involvement included

• Citizens• Water Resource Advisory Board• City Council


City of Boulder Water Budget Rates Staff, WRAB selected water budget structure

from number of alternatives City Council endorsed water budget rate structure

in December 2004


Boulder Water Budget Rate Structure 5-tiered increasing block structure (volumetric)

Rates for each block are the same for each class

Block threshold based on each customer’s monthly budget

Block threshold stated as percent of total monthly budget


Boulder Water Budget Rate Structure Budget calculation based on customer class

Residential – Indoor allowance + Outdoor allowance

Multifamily – Indoor allowance + Outdoor allowance

Nonresidential – Average Monthly Usage (AMU)Irrigation – Outdoor allowance based on irrigable area


Boulder Water Budget Rate Structure

Rate (per 1,00 gal)

Block Size(% of budget)

Block 1 $1.95 (3/4 x base rate) 0% - 60%

Block 2 $2.60 (the "base rate") 61% - 100%

Block 3 $5.20 (2 x Base Rate) 101% - 150%

Block 4 $7.80 (3 x Base Rate) 151% - 200%

Block 5 $13.00 (5 X Base Rate) Greater than 200%


Boulder Residential Water Budget Rates Indoor allowance

Single family – 7,000 gallons/monthMultifamily – 4,000 gallons/month/unit

Outdoor allowance Irrigable area “pervious area”

• Single family – 3-tiered gallons/sq ft threshold basis– Tier 1: 0 to 5,000 sq ft @ 15 gal/sq ft– Tier 2 : 5,001 to 14,000 sq ft @ 12 gal/sq ft– Tier 3: >14,000 sq ft @ 10 gal/sq ft

• Multifamily – 15 gallons/sq ftAllocated on a monthly basis using ET indexET Index = Evapotranspiration Index


Percentage of Monthly Outdoor Budget

0%

5%

10%

15%

20%

25%

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Based on evapotranspiration index


Boulder Nonresidential Water Budgets Commercial/Industrial

Average Monthly Usage (AMU) Irrigation

Irrigable area “pervious area” – 15 gallons/sq ftAllocated on a monthly basis using Et indexEt Index = Evapotranspiration Index


Single Family Example Pervious area = 6,000 sq ft Indoor Annual Budget:

7,000 gal/month * 12 months = 84,000 gallons Outdoor Annual Budget:

5,000 sq ft * 15 gallons/sq ft = 75,000 gallons

+ 1,000 sq ft * 12 gallons/sq ft = 12,000 gallons

Total Outdoor Allowance 87,000 gallons

Total Annual Budget 171,000 gallons


Monthly Water Budget (indoor/outdoor)

0

5,000

10,000

15,000

20,000

25,000

30,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Gal

lons


Single Family Example (continued) July usage = 30,000 gallons July budget:

7,000 gallons + 87,000 gallons * 20%July budget = 25,000 gallons

July volume charges for 30,000 gallons usage:Block 1: 0 to 15,000 gallons: 15 Kgal * $1.95 = $29.25Block 2: 15,000 to 25,000 gal: 10 Kgal * $2.60 = $26.00Block 3: 25,000 to 38,000 gal: 5 Kgal * $5.20 = $26.00

Total July Volume Charges: $81.25


What’s in Store for 2008 Continue to monitor changes in usage patterns Irrigable area adjustments Right-of-Way adjustments Reviewing commercial and industrial budget basis

Average monthly usageHistorical monthly usageIndoor/outdoor allocations

Continued community involvement


Discussion

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