Local Government User - City of Berkeley - Hazard Identification, Public Education, and Hazard Mitigation
Utility User - East Bay Municipal Utility District - Seismic Improvement Program
Real Estate Disclosure Companies - JCP Geologists, Inc.

Notably, at least two large real estate disclosure companies (JCP Geologists, Inc. and e-RISK) do NOT use the On SHAKY Ground maps in their routinely issued disclosure reports. The key reason for this decision is that these companies are not required to disclose the maps as part of the state-required Natural Hazard Disclosure Statement. Only if a city or county adopts the ABAG maps as part of their General Plan or in a local ordinance which specifically requires disclosure are companies obliged to disclose the maps. A description of the rationale used by JCP Geologists is included following the Berkeley and EBMUD descriptions.

The following summaries were prepared by representatives of these agencies in 1998.

The City of Berkeley has used the maps from On SHAKY Ground for identifying the shaking hazard, communicating that hazard to the public and federal officials, and mitigating some of those hazards.

Elected officials, staff, and community members have referred to the maps and written materials provided in the report in a number of public forums and workshops on communicating the earthquake hazard in the City.

In recent meetings with federal officials, the maps were useful tools for showing the seismic issues Berkeley faces overlaid with the urban-wildland interface. The graphic presentation demonstrated, too, Berkeley's serious exposure to severe geologic hazards. This information coupled with building stock data made for sobering talk about pending hazard mitigation funds.

City staff have used the maps to make decisions about retrofit projects; to update municipal planning documents; and while conferring with community members about the relative risk in the regional environs. The City's general plan is currently being revised; hazard assessment information and graphics from the document will be cited in the Safety and Housing Elements.

The maps were also used in a series of community meetings detailing Berkeley's seismic risk when the voters were being asked to approve a hazard mitigation bond measure to upgrade Berkeley's main library and city hall.

On SHAKY Ground has been a popular and widely used publication in Berkeley.

Summary prepared by Arrieta Chakos, City of Berkeley.

• 5,500 pipe breaks
  
• major water tunnel failures cutting off sections of service area
  
• loss of 65 distribution reservoirs
  
• 87 pumping plants out of commission
  
• two-thirds of population without service for up to 6 months

Financial impacts in the EBMUD service area could be as much as $2-billion in repair costs and business-related losses, about ten times as much as the cost to protect the system in advance of a quake.

These impacts were identified prior to the availability of the On SHAKY Ground maps. However, after publication, these maps were then used to ensure that the conclusions of the general shaking and pipe rupture hazards were consistent with earlier predictions.

When the original EBMUD study revealed the extent of the risk, EBMUD's Seismic Improvement Program (SIP) staff proposed a $189-million program to strengthen the water system against major quakes on the Hayward, Calaveras and Concord faults. They asked customers if they would support and pay for the program and more than 90-percent of respondents said yes. In 1994, the Board of Directors told the SIP team to get the work done, and meet a fast-track 10-year schedule.

EBMUD's Internet Site prominently features a reference to this Seismic Improvement Program. (See - http://www.ebmud.com/ebmsip/sip.html ) This public information site features a link to ABAG's Internet site for On SHAKY Ground maps on the Hayward fault.

Summary prepared by Seismic Improvement Program Staff, EBMUD.

Real Estate Disclosure Companies - JCP Geologists, Inc.

The Maps - It is important to note that the ABAG ground shaking maps are not the same as "Seismic Hazards Maps" produced under the 1990 Seismic Hazards Mapping Act. Seismic Hazards Maps are prepared by the California Division of Mines and Geology and designate areas subject to landslides, liquefaction and amplified ground shaking. Although, the ABAG maps delineate earthquake ground shaking intensity, they are not the same as those that may appear on the Seismic Hazard Maps.

The ABAG maps are just one set of many geologic maps produced by government agencies. They provide information on where ground shaking intensity would be the greatest and least from an earthquake along the major faults in the Bay Area. Ground shaking intensity is mapped using the modified Mercalli scale. This scale measures how intense an earthquake was by using the extent of damage that occurred. For example, blue areas on the ABAG maps show areas where shaking might be expressed as nothing more than small objects falling off shelves whereas areas that are colored black represent severe ground shaking areas. According to ABAG, the maps were produced by computer modeling and take into consideration earthquake size, distance to the fault, and the type of geology underlying the area (i.e. generally amplified shaking in softer soils and decreased shaking in bedrock areas).

The ABAG maps do not trigger a specific disclosure requirement like the Alquist-Priolo Fault maps or the NFIP Flood maps. The ABAG maps are not printed at a large enough scale to easily permit a site-specific determination. In addition, street names are generally not shown. The intent of these maps is to provide general public awareness of ground shaking intensity on a neighborhood by neighborhood basis and to suggest ways to mitigate the damage this hazard can cause.

To Disclose or Not to Disclose - The recent legislation which introduces the Natural Hazard Disclosure Statement for use in residential transactions does not include the ABAG maps as a required disclosure. However, some local planning departments may adopt portions of the maps for use in making construction or building permit decisions. If this is the case, then local disclosure requirements may apply. The best way to be sure about this is to either call the local planning department or use a disclosure provider that includes local area disclosure items such as the Seismic Safety Element in the General Plan. Also, the general publicity that has surrounded the maps to date may have buyers and sellers asking questions about them which could make it an item to address. So, while disclosure of information based on the ABAG maps may apply to some transactions, it is not universally required. Furthermore, it is important to note that the information on the ABAG maps does not satisfy the disclosure requirements of the Natural Hazard Disclosure Statement.

Summary prepared by JCP Geologists, Inc.