Expected successSuccess CriteriaAerial Photography DataAerial Photography DataSuccess CriteriaAssessing a Caltrans Reclaimed Wetland with Geographical Information Systems Denise Leong Abstract Wetland ecosystems are highly productive and vital to the environment due to the diversity of biological, physical and chemical attributes within each system. Unfortunately, loss of wetlands has been extensive since industrialized development began. In response to this, the government has instituted “No Net Loss” legislation to prevent further damage and restore previously damaged environments. The California State Department of Transportation (Caltrans) along with many other organizations have incorporated wetland creation, restoration and mitigation plans into their agenda. However, created wetlands have been criticized for being inadequate and ineffective in replacing the functionality of natural wetlands (Revkin, 2001). Despite the legal mandates designed to restore wetlands, the effectiveness of the legislation efforts has been difficult to gauge. More effective approaches to wetland management have been suggested and explored. (La Peyre et.al. 2001). One approach is the integration of Geographical Information Systems (GIS) with conventional wetland management methods to improve the speed of assessment (Wolfson et al., 2002). This case study of Caltrans’ reclaimed wetland, Guadalcanal Village will have two main goals, to evaluate Caltrans’ current vegetation assessment practice and to utilize and gauge aerial photography as an alternative method in vegetation assessment. The current state of the wetland’s vegetation will also be appraised to determine if it meets the success criteria set by Caltrans. This study will examine the existing vegetation data available from Caltrans as well as the aerial photography and Arc View GIS and compare each source to the success criteria set by the mitigation plan. It is hypothesized that the current vegetation will not meet the success criteria and that utilizing aerial photography and GIS analysis to assess the wetland vegetative health is viable and will yield reliable data. While results suggest that according to Caltrans’ method of vegetation assessment, the wetland site is meeting the success criteria, aerial photography data contradicts these results and shows that the wetland site does not meet the success criteria.Introduction The role a wetland can play is both vital and diverse. Wetland ecosystems are highly productive due to the diversity of biological, physical and chemical attributes while being home to numerous species of microbes, plants, insects, reptiles, amphibians and birds (EPA, 2002). High nutrient richness of wetlands allows for an abundance of the organisms at the base of the food web (EPA, 2002). Wetlands can also provide societal, recreational and cultural values, such as outlets for floodwaters, maintenance of water quality, aesthetics and more (US Army Corps of Engineers, 1995). Unfortunately, the rate of loss of wetlands has been extensive. It is estimated that over half of the United States’ wetland habitat has been dredged or converted to other uses. While major losses occurred in the 1970s, increased awareness has lead to more regulatory legislation. The loss of original wetlands is still occurring at an estimated rate of at least 100,000 acres a year in the United States with California suffering the greatest loss at 91% of its original wetlands already destroyed. In addition to losses, wetlands also suffer degradation both from human activities and natural causes (EPA, 2002). The California State Department of Transportation (Caltrans) is under legal mandate to comply with all state and federal laws regarding wetlands and wetlands protection. These laws include the California Environmental Quality Act, National Environmental Policy Act, and sections 401 and 404 of the federal Clean Water Act established in 1972. (CEQA, 1970, NEPA, 1969 and CWA, 1972) In addition, section 10 of the Rivers and Harbors Act, and the President’s Executive Order 11990 must be considered (Caltrans, 1997). Under these “No Net Loss” policies, all Caltrans projects that impact wetlands through disposal of dredged or fill material into wetlands and/or the paving over of wetlands must obtain federal and state permits. In order to obtain these permits, Caltrans must include a mitigation plan that details the compensation of the loss of the existing wetland. Compensation is mainly achieved through the creation of new wetlands (Wilson, 2002). The mitigation plan must replace at least 1.8 acres of wetlands for every 1-acre that the project destroys, as well as include a monitoring program to assess the functionality of the wetland (Revkin, 2001). In response to legislation, Caltrans along with many other organizations have incorporated wetland creation, restoration and mitigation plans into their agendas. From 1982 to 1992 alone, a total of 768,700 acres of wetlands were gained as a result of restoration activities around thenation (EPA, 2002). While these statistics are impressive, created or artificial wetlands have been criticized for being inadequate and ineffective in compensating for the loss of natural wetlands (Revkin, 2001). One study that focused on compensatory wetland mitigation in the San Francisco Bay Area found that the majority of these wetlands cannot be classified as complete, active or successful (Campbell et al., 2002). Despite legal mandates designed to save and manage wetlands, the effectiveness and outcomes of these legislation efforts have been difficult to gauge. With such aspects of wetland resource management as creation, impacts, and quality, a more progressive and rapid approach to wetland management is needed (La Peyre et.al. 2001). One alternative management approach that has been experimented with is the integration of geographical information systems (GIS) with conventional wetland management methods (Wolfson et al., 2002). A study conducted in Michigan, USA, developed a wetlands information system for assessing wetland functions. They combined the standard National Wetlands Inventory codes, site visits, and GIS technology to define and assess the function and value of two-wetland site (Wolfson et al., 2002 and NWI, 2002). This study examined Caltrans’ current vegetation assessment practice and compared the current state of the reclaimed wetland to success