Ventura County Grand Jury
• 2001-2002
An Inquiry into the Environmental Impact at the Lang Ranch Dam Project Background and Methodology
⚠️ Translation Notice: This content has been automatically translated. The original English text is the official version. Translation may contain errors.
⚠️ Este contenido ha sido traducido automáticamente. El texto original en inglés es la versión oficial. La traducción puede contener errores.
Findings and Recommendations 6 findings
F1
The project director, Deputy Director of the Ventura County Flood Control District, conducted the on-site meeting and explained how the Lang Dam project became necessary. Since the surrounding area’s new development has caused large parcels of land to be paved, rainwater is no longer able to soak into the ground and instead runs off in large torrents to inundate and damage anything downstream. The dam is necessary to manage and control such large torrents, thereby protecting downstream property and environment from fl ood damage.
No recommendations for this finding
F2
The Agreement between the City of Thousand Oaks, the Lang Ranch Company, the County of Ventura and the County of Ventura Flood Control District was signed on December 19, 1995. The Project Description for Lang Ranch Basin, a part of the Agreement, describes the project as the con- struction of an 11.5-acre stormwater retention basin, debris basin, access roads and related drainage structures. The permanent detention facility will be constructed to protect downstream property from a “100-year frequency storm fl ow,” a storm of epic proportions, as well as the usual storm runoff.
No recommendations for this finding
F3
Concerns regarding the impact of building a dam on unstable landslide materials were put to rest with the explanation that: a. the landslide was located about two to three hundred yards to the southwest and downstream from the site, and b. the Ventura County Flood Control District had the composition of bedrock to which the dam will be attached test drilled for stability in multiple locations under the direction of geologists. County Services, Special Districts 4-1 Final Report 2001-2002 Ventura County Grand Jury
No recommendations for this finding
F4
Necessary permits and waivers required for the construction of the project have been applied for, approved and are a matter of public record at the Ventura County Recorder’s offi ce.
No recommendations for this finding
F5
The 1995 Agreement contains a clause entitled “Oak Tree Protection and Removal.” It provides a detailed plan for the removal of 60 trees and the preservation of the remainder of the grove. Citizen concerns about the number of oak trees that would be destroyed as a result of the dam con- struction and fi ll behind the dam were addressed. The Grand Jury learned that the original estimate of trees to be destroyed was reduced in number from approximately 140 to approximately 40. An arborist hired by the County determined that of the trees being removed, most had lived well beyond their projected life span and many were also diseased.
No recommendations for this finding
F6
In the event of a 100-year storm, water collected behind the dam will be dispersed within 24 hours, and no permanent lake will be formed. There- fore trees and environment upstream from the dam will also be protected. Conclusions C-1. The Lang Ranch Debris and Retention Basin project has been in existence since at least 1995, and in that time every effort has been made to identify and resolve any issues of environmental impact raised by its construction. C-2. Concern about the building of the dam on unstable land was based on misinformation, and the fact is that all required studies have been made, and safety issues have been settled. C-3. Regarding the destruction of old growth oak trees, the fact is that the purpose of the project is to protect the environment, and environmental impact has been properly addressed. Recommendations None Responses Required None 4-2
No recommendations for this finding
Conclusions 1
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CL1 Page 2C-1. The Lang Ranch Debris and Retention Basin project has been in existence since at least 1995, and in that time every effort has been made to identify and resolve any issues of environmental impact raised by its construction. C-2. Concern about the building of the dam on unstable land was based on misinformation, and the fact is that all required studies have been made, and safety issues have been settled. C-3. Regarding the destruction of old growth oak trees, the fact is that the purpose of the project is to protect the environment, and environmental impact has been properly addressed.