Assessment Districts Background


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

Landscape Assessment District Boundary Map No 41


District is bounded by Pathfinder Road to the north, Brea Canyon Cutoff to the south, and SR 57 to the east. It comprises 544 parcels, 12 acres of slopes, 3 acres of brush. PDF Map

Maintenance Work

Weekly or As-Needed: City contractors inspect district areas and carry out a variety of maintenance work that includes leaf and V-ditch cleanup, weed control, pest abatement, landscape trimming and pruning, removal of felled trees and branches, and irrigation.

Annual: Every year in May, the City inspects hazardous brush and vegetation conditions throughout the district, and contractors create preventive firebreaks along critical areas using hand tools, tractors and other equipment.

Annual: To supplement the brush clearance work, particularly in the canyons and areas that are not accessible to hand crews or tractors, the City uses goat grazing. The herds of goats (between 150 and 300)  are supervised and are on contract for approximately eight weeks.

  1. LAD No. 39

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.