Identifying Indoor and Outdoor Water Use

1
Identifying Indoor and Outdoor Water Use

• Craig W. Miller
• Utah Division of Water Resources
• November 26, 2002

2
Average Salt Lake Water Use
3
Understanding Municipal Water Use

4
Utah is a water poor state
5
Breakdown of water use by category
Understanding Residential Outdoor Water Use is
Key to Conservation
6
Outdoor Water Use

• Determine use per day December-February
• Subtract from use in remaining months to obtain
  outdoor water use.
• Determine from tax assessor records to determine
  number of swamp coolers, subtract 45 gpd for
  each.
• Determine lot size from assessor database to find
  use per acre (this is the focus of remainder of
  presentation).

7
Address Matching Use Post Office Zip4 For
Greater Accuracy

• Problems requiring address matching
• In order to determine outdoor water use
  efficiency, billing records need to be tied to a
  lot size in the tax assessors database.
• Water purveyors give overlapping boundaries for
  their service areas. In order to determine
  population served correct boundaries must be
  determined.
• Data exists which relate measured lot size to
  area of irrigated landscape. Unfortunately, the
  measured lot size does not match the tax assessor
  lot size. Since addresses are available, find
  the tax assessor lot size to create a function
  which relates tax assessor lot size to landscaped
  area.

8
Methods Used for Address Matching

• Home grown methods
• Variant/alternate spellings of addresses produced
  low match rates (50-60)
• Geocoding
• Products for geocoding readily available through
  state or local agencies.
• Can purchase products from ESRI.
• Often finds a limited number of matches (85) and
  may not exactly locate a lot or may find the
  wrong lot.
• Post Office Zip4 address standardization
  yields roughly a 95 find rate in test runs.

9
Correctly Identify Boundaries

• Needed for
• Population estimation
• Per capita use
• Water planning

10
Readily Available Data SetsUsually Free of Charge

• County Recorder Lot Coverages
• Correctly identify lot size
• County Assessor Tax Database
• Address of property
• Identifies use commercial, single family
  residential, etc.
• Estimate of lot size
• Property valuation
• Number of swamp coolers and bathrooms
• Water purveyor billing records
• USPS zip4 (always free)

11
Boundary Problems

• Typical maps of water purveyor boundaries do not
  represent system complexity at the user level.
• Lack of communication between GIS personnel and
  system administrators
• Small pockets of purveyor service can exist at a
  neighborhood level.
• Federal funding guidelines encourage
  gerrymandering.

12
Zip4 Capabilities

• Can be interactively queried
• Post Office provides free DLLs but these require
  access to a server and are not well documentedno
  help files.
• Simple programs written in VB and JAVA can do the
  same thing.
• Capabilities
• Resolves alternate spellings
• Can be used to make an exact key for address
  matching (5-digit zipAddress)

13
Zip4 Resultshttp//www.usps.com/zip4/

• Example
• 510 Seventh Avenue
• 510 7th Ave
• 510 East Seventh Ave
• All yield
• 510 7th Ave

14
Zip4 Resultshttp//www.usps.co/zip4/

• Examples - continued
• 6790 Hollow Dale Dr
• 6790 South Hollowdale Drive
• Both yield
• 6790 Hollowdale Dr
• Clearly indicates when address is not found
• Conclusion Very robust system

15
Zip4 Problems

• Sensitive to zip code or city boundary changes.
• Does not resolve all variant spelling problems.
• Pony Express Way returns Pony Express Way.
  Likewise for the same address, State Street
  returns State Street.
• Alternate city spellings are not usually
  corrected.
• With 95 find rate, database cleanup is much less
  of a problemstill not trivial.

16
Trial Case

• Identify South Salt Lakes Water Service
  Boundary.
• Claims to serve same areas as Salt Lake City and
  Jordan Valley Water Conservancy District.

17
Address Preprocessing

• Remove notes in billing record addresses placed
  there by the company
• (for example notes in parenthesis)
• Resolve address range problems
• Represent (213-215) Some Street Dr with 213 Some
  Street and 215 Some Street?
• Zip4 does not recognize CR as an abbreviation
  for Circle.
• (other problems will be noted for your dataset)
• Create records for variant names (not just
  alternate spellings).

18
Address Processing

• Takes about 1 second per query.
• To speed process have subsets of your database
  being processed in tandem.
• VB processes for web querying take all processor
  cycles available (may take a performance hit in
  other processing).

19
Address Post Processing

• Remove apartment and suite number
• Create a unique key from zip address
• Access and ArcGIS are limited in their ability to
  handle long keys (example 60 characters).
  FoxPro was used to perform the database linkages.
• Find parcel number field and place in database of
  interest. Addresses, zips, and cities change.
  County parcel numbers are less volatile.

20
VB program used for project
Code available at water.utah.gov/craig/code.zip
21
Sample Output
22
Acknowledgements

• Utahs Water Resources, Planning for the Future,
  Utah Division of Water Resources, 2001.
• Salt Lake City, South Salt Lake, Salt Lake
  County, Jordan Valley Water water records,
  property records.