Assessment Districts

Update as of May 31, 2019 - Ballots and information were mailed to property owners

Assessment Districts have been in existence in California since the early 1900s. They are meant to establish a revenue stream funded by property owners within any defined geographic area to pay for certain services or improvements from which they benefit.

Local Assessment Districts

Diamond Bar Landscape Assessment District Nos. 39 and 41 were created by the County of Los Angeles in the mid-1980s. Upon incorporation in 1989, the City assumed the responsibility of administering the three districts and the contracts for maintenance services. Maintenance Specs


For at least the last 10 years, the City's General Fund has covered the districts' funding shortfalls. This has ensured essential maintenance of district areas is continued at appropriate levels. However, considering the districts were intended to be self-supporting, these continuous annual subsidies are not a permanent solution as it results in diverting money the City should use for other services, such as law enforcement and public park and street maintenance. April 16, 2019 City Council Agenda Report

VIDEO (30 min): A presentation on landscape assessment districts and the ballot proceeding procedure as set by Proposition 218 (Article XIIID of the California Constitution) is provided by John Bliss, a state licensed professional civil engineer, with SCI Consulting Group at the regular Diamond Bar City Council meeting of May 21, 2019.

  1. LAD No. 39
  2. LAD No. 41

Landscape Assessment District Boundary Map No 39 Opens in new windowAbout

District is bounded on the west by Diamond Bar Boulevard and on the east by city limits. It comprises 1,249 parcels, 15 acres of slopes, 39 acres of brush, and five mini parks. PDF Map

Maintenance Work

Daily: Every day, City contractors inspect district areas and carry out a variety of maintenance work that includes debris and litter removal, playground cleanup, irrigation system checkup and repairs

Weekly or Biweekly: Every week April through November, City contractors mow, edge and trim landscaping that include turf, shrub and ground cover areas. Work frequency switches to biweekly December through March.

Annually or As-Needed: Once a year or as needed, City contractors perform fire-preventive brush clearance that includes cutting down and removing overgrown weeds and dead vegetation on hillsides and canyons close to homes. Rodent, insect and disease control within landscaped areas is handled when necessary.

Engineer's Report

Engineers-Report-for-District-39-coverEngineers-Report-for-District-41-cover Opens in new window

Proposal to Increase Assessments

During its regular meeting of April 16, 2019, the Diamond Bar City Council initiated a ballot process, consistent with the legal requirement of Proposition 218 (Article XIID of the California Constitution) to adjust the annual assessment for properties within LAD Nos. 39 and 41.  That process involves a mail-in ballot proceeding and culminates in a public hearing in front of the City Council.  City staff is holding a series of neighborhood meetings to provide information to property owners who will be asked to vote on these increases.  Since the issues in District No. 39 and District No. 41 are somewhat different, the meetings will be specific to each district.

Meeting for District No. 41 Property Owners
Meeting for District No. 39 Property Owners
Monday, May 13, 2019
6:30 – 7:30 p.m., and again 7:30 – 8:30 p.m.
Heritage Park, 2900 S. Brea Canyon Road
Tuesday, May 14, 2019
6:30 – 7:30 p.m., and again 7:30 – 8:30 p.m.
Diamond Bar Center, 1600 Grand Avenue


April 16May 13 & 14May 21May 31July 16
Diamond Bar City Council initiates assessment ballot proceedingNeighborhood meetings take place to provide information to property ownersDiamond Bar City Council reviews the Engineer's Report and authorizes ballotsBallots are mailed to property owners within each of the assessment districtsDiamond Bar City Council holds a public hearing and tabulates ballot results

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