GIS was used to quantitatively assess and map compliance with policies of the land use element in the Malibu/Santa Monica Mountains Interim Area Plan within Calabasas during 1980-91. More than half of the tracts in Calabasas were approved in the 1980s and cover two-thirds of the city's developed area. Half the tracts were approved for at least twice maximum density, and one-third were five to 12 times over maximum. Development approvals urbanized an area envisioned by the Area Plan as rural. The Los Angeles Times subsequently used the GIS methodology to investigate development approvals throughout the Santa Monica Mountains.
This study of land use policy compliance encompasses the City of Calabasas. Calabasas, the newest city in the Santa Monica Mountains, was incorporated in 1991 to gain land use control from Los Angeles County. The western end of the Santa Monica Mountains in southwestern Los Angeles County, California, is noted for being a highly desirable place to live owing to its outstanding natural beauty, nearness to major employment centers in Los Angeles, rural atmosphere, clean air, numerous recreational opportunities, excellent public schools, and lower crime rate. Furthermore, the region holds national interest in that, in 1978, Congress established the Santa Monica Mountains National Recreation Area, the unit of the National Park System representing this nationís best example of the Mediterranean ecosystem. Nevertheless, the desirability of the region has led to rapid development in the past three decades that, on one hand supplies housing to fill a strong demand, and on the other, eliminates natural open space and its associated value to both humans and native biodiversity.
Calabasas is an area that has been subject to rapid development. In the 1980s and early 1990s, there was controversy over proper adherence to land use development policies as outlined in the Malibu/Santa Monica Mountains Interim Area Plan and county-wide General Plan. The public's viewpoint has been that several developments were approved in spite of not following the land use recommendations provided in Interim Area Plan. Non-compliant land use and land use densities were granted so frequently that the Interim Area Plan became widely acknowledged as long-outdated and often ignored. Developments destroyed uninterrupted viewsheds of natural terrain and were built on steep hillsides and ridge tops subject to wildfire and erosion.
Land is a finite resource. Whether to maintain an area in its natural state or to develop it is an extremely important decision that should be based on long-term impacts rather than short term benefits. In order to make good land use planning decisions, information about the status of land use development is vital. At issue in this case study was the problem that general plan compliance or non-compliance was essentially a qualitative judgement. What was missing in the land use plan evaluation was a quantitative analysis of deviation from the original plan. Without a system that can compile the number and type of changes, one can only surmise that extensive changes have actually occurred. The methodology implemented in this study was designed to quantitatively reveal and illustrate information about compliance or non-compliance with development policies for the Calabasas area.
In order to analyze land use development policy compliance, the construction of "before" and "after" scenarios were necessary which dealt with:
1) development policy as proposed: the baseline land use development policies and map that portrays general locations to which those policies apply; and
2) land use development as approved: year the development approval was recorded, location and size of development, number of lots per development, and land use associated with the lots. Please note that, although this project used recordation date to track what planning document a project was subject to, it is more appropriate to use date of final project approval rather than recordation date.
As with most any GIS project, the lengthiest part of the study was compiling the data into useable digital format. Four groups of information were compiled.
* Digital baseline prescribed development policy. The 1980 Malibu/Santa Monica Mountains Interim Area Plan had to be digitized.
* Temporal data demarcating development approved during the study period. Recordation date of the tract map was used in this study. In actuality, date of final approval by the Los Angeles County Board of Supervisors would have been a more accurate representation of development approval during the study period. Recordation of a tract map can take many years; a tract may have been approved prior to adoption of a planning document, yet the map may have recorded during application of the planning document.
* Geographic location of approved development. This information was most difficult to obtain. There was no consolidated location at Los Angeles County for tract development approvals. The author had to glean information from the County, the local water district, and consult by hand the Map Books at the County Recorderís Office.
* Current land use data. Tabular Metroscan data was obtained from Los Angeles County Assessorís Office. Establishing a relational database between the tabular database and the GIS locational database was extremely labor intensive. A relational field had to be set up, and manually populated for over 5,000 tract/lot records from Metroscan.
The analysis consisted of gleaning desired data from the "before" and "after" scenarios. The first step was to carry out a process that geographically combined the "before" and "after" geo-referenced data. The Malibu/Santa Monica Mountains Interim Area Plan underwent the Arc/Infoģ "union" operation with the tract approvals coverage illustrates the basic overlay of tract approvals over the Interim Area Plan. The union process created a coverage that contained features from both input coverages. The process added to the tracts coverage the geographic boundaries of Interim Area Plan polygons coded for development policy. The unioned coverage could then be queried to obtain information pertinent to the analysis at hand. The GIS cornerstone to the analysis was its union, frequency, and geographic/tabular reselection utilities.
1. Number of Tracts Approved Each Year: Tract approvals were grouped based on the date the tract was recorded at Los Angeles County Recorder's Office. The table revealed a peak of development approvals in the 1980s. A total of 129 approvals have been granted. In the 1980s, 71 approvals were granted, or 55% of all approvals.
2. Developed Acreage, pre-1980 and post-1980: Tract acreage was summed by decade of approval. Less than 1/3 of developed area was approved during 40 years, and more than 2/3 was approved during 11 years.
1. Digital Relationship between Prescribed and Approved Development: The Interim Area Plan digital coverage was geographically unioned with the Approved Tracts digital coverage in order to analyze intersecting polygons.
2. Multiple Interim Area Plan Land Use Designations with a Tract: A tract's area could cover more than one type of land use designation. The acreage of each land use within a tract was calculated.
3. Prescribed Dwelling Units per Tract: Land use acreage was multiplied by the designated number of dwelling units per acre as prescribed in the Interim Area Plan, and then multiple land use designations were summed to provide the total number of prescribed dwelling units for the tract. If the land use designation permitted no residential development, the number 1 was assigned in order to avoid problems associated with dividing and multiplying by zero.
4. Approved Dwelling Units per Tract: Tabular parcel information was grouped according to the number of times a Tract Number appeared in the parcel information. If a Tract Number appeared in 100 records, then that tract had been approved for 100 dwelling units.
5. Ranking Compliance or Non-Compliance: A tract's approved dwelling unit density and number of dwellings was calculated as a percent of the prescribed density and number of dwellings. The calculations were then sorted by that percent figure. From 1980-1991, 69 tracts were approved:
* 72% of tract approvals exceeded prescribed policy
- 36% doubled prescribed policy
- 14% exceeded prescribed policy by 3X - 5X
- 9% exceeded prescribed policy by 6X - 10X
- 13% exceeded prescribed policy by more than 10X
6. Geographic Location of Residential Development: Residential land use designations from the Assessor's Office were grouped to reveal acreage and numbers of dwelling units. Analysis revealed that high density residential land use was permitted in locations zoned for virtually no residences, and is located at least four miles from any major grocery store.
7. Open Space Dedications: Vacant Residential Land acreage, as designated in the Assessor's Office parcel data, was summed.
--> 47% of residential acreage was dedicated to remain open space (policy states a minimum of 50%). However, further analysis would be necessary to reveal the degree of compliance or non-compliance with open space dedication policies because 52% of the study area lies within Hillside Management Areas that require a minimum of 70% open space dedication.
Extremely high dwelling unit densities were approved relative to prescribed densities. The studyís results indicate that, if the Los Angeles County General Plan of 1980 and the Malibu/Santa Monica Mountains Interim Area Plan were intended to guide future development, then implementation failed. Policies in the county-wide General Plan as well as the Malibu/Santa Monica Mountains Interim Area Plan were, in many instances, grossly ignored.
Moreover, when high density was approved, most General Plan and Interim Area Plan policies relating to environmental protection, public safety, and aesthetic design also were disregarded. The suburbanization of Calabasas channelized natural streams and cut off wildlife movement. Massive grading literally flattened mountains and filled in canyons. Development within the Santa Monica Mountains National Recreation Area brought views of tract-style housing from numerous recreational trails, irreversibly destroying park visitorsí perception of unobstructed, natural landscapes.
In 1998, Los Angeles Times reporter T. Christian Miller used the authorís GIS methodology to analyze development approval throughout the entire unincorporated area of Los Angeles County in the Santa Monica Mountains. The Times also investigated the social and political causes for changing the plan and the financial impacts of the excessive development in a disaster-prone region. The article was a front page Sunday report and has been referenced in many, many instances. Even with the revival of the economy in the late 1990s, there have been virtually no projects approved at elevated density levels. Planning documents have been followed. The authorís GIS study led to an article that literally changed the way planning is done for the Santa Monica Mountains.
In conclusion for the GIS world, this GIS-driven study shed light on land use development abuse of astonishing proportion. The results and their public disclosure changed the course of planning in an area holding national interest. No less than 25 municipalities called the L.A. Times to find out how they might have such a study done for their area. Clearly there is the need and opportunity for planning departments and the interested public to use GIS to keep track of general plan compliance.