Remote Sensing Evaluation of Compensatory Wetland Mitigation Regulated under the Clean Water Act in California, USA

• Main Author: McMeechan, Melissa Margaret
• Language: EN
• Published: University of California, Los Angeles 2017
• Subjects: Ecology|Natural resource management|Remote sensing
• Online Access: http://pqdtopen.proquest.com/#viewpdf?dispub=10666340

<p> Impacts to wetlands protected under Clean Water Act Sections 401 and 404, can require mitigation with the goal of no net loss of acreage and function. Several studies of compensatory mitigation concluded this goal has not been met, resulting in cumulative losses. Many of these studies were completed by permit review or post-mitigation field survey. However, few studies evaluated condition before and after impact and mitigation activities as a comparison of losses and gains to assess net loss of wetlands.</p><p> Ambrose et al. (2007) evaluated both compliance and wetland condition for CWA &sect;401 mitigation projects throughout California. As a continuance of the studies of Ambrose et al. (2007), this thesis evaluated the change in condition as a result of impact and mitigation activities to address whether no net loss was achieved. A rapid assessment methodology was adapted to evaluate wetland condition using aerial photographs.</p><p> As hypothesized, impact activities decreased the wetland condition at the majority of sites. However, mitigation activities often did not increase condition. Therefore, no net loss was not achieved for most projects. Furthermore, this study illustrates the pitfalls in an evaluation of no net loss based solely on the mitigation site condition after the project implementation. The observed wetland condition may have been present at the site prior to mitigation activities. This is a misleading assumption in the assessment of gains from the project. Therefore, the change in wetland condition should be assessed through an initial evaluation of site conditions, as well as part of on-going monitoring.</p><p>