The
Environmental Integrity Index (EII) is a tool developed by the
City of Austin's Environmental Resource Management Division to
monitor and assess the ecological integrity of Austin watersheds.
Water chemistry data is collected quarterly
and biological and habitat surveys are conducted once per year
in the summer.
Water quality data summariesfrom the most recent EII sampling events for each watershed can be accessed by clicking on the appropriate watershed in the table below.
The annual EII reportsinclude watershed summaries in addition to the raw data and a compilation of the annual results. The three most recent annual reports can be accessed by clicking on the appropriate report below.
Phased monitoring of Austin’s watersheds began in 1996 when the EII program was organized into three separate phases which were sampled on a three year rotating basis. Phase 1 included the urban watersheds, Phase 2 included peripheral urban and suburban watersheds and Phase 3 included primarily suburban watersheds. A drawback to the phased rotation is that each watershed is only monitored once every three years in our rapidly developing environment.
Changes to the EII monitoring schedule continue to improve resolution and efficiency. An analysis of data from the past decade indicated that several of the EII sites could be dropped in order to make room for a revision of the program toward a two-phase rotation. Starting in 2009, Phase 3 will be dissolved. The watersheds formerly in Phase 3 will be incorporated into Phases 1 and 2. This will increase the frequency watersheds are monitored without significantly increasing the cost of the program. Details of the current project plans can be accessed by clicking on the appropriate report below.
