The Inland Waters and Wetlands Chapter in this SoE Report reviews freshwater water resources under two broad topics: condition and threatening processes. Within these topics, eight issues are examined - water quality; water quantity and water use; groundwater; health and extent of native riparian vegetation; aquatic health; wetlands; wild rivers; and landuse and inland waters. More detailed information is provided in the Inland Waters and Wetlands Chapter.

Water Quality: Exceedences of the ANZECC (2000) aquatic ecosystem guidelines (adapted for Tasmanian conditions) were recorded for a range of water quality parameters. Sites with a high number of turbidity exceedences of ANZECC guidelines are typically those surrounded by agricultural land or impacted by mining, while forested sites in the Southern Forests showed few exceedences. Conductivity exceedences occur for a number of rivers particularly during low flow periods, and tend to increase as rivers approach the coast. Prolific algal growth resulting from high nutrient levels in streams is noted at specific sites. Metal exceedences are seen in the Pieman and Savage River mining areas. Little monitoring of metals has occurred recently in the King River as monitoring efforts are focussed on downstream impacts on Macquarie Harbour.

Water Quantity and Water Use: Since the last SoE Report (1997), some 907 dams have been approved although most of these are presently 'proposed' rather than 'existing'. As at September 2002, the Water Information Management System database registered 5,516 existing dams (both in-stream and off-stream) for irrigation, stock, and stock and domestic uses. Growth of water use for irrigation since the last SoE Report is shown to be occurring by about 7% per annum. The ABS Water Account for Australia (ABS 2000) reported that Tasmania had the lowest mean household water usage of 176 kL/year. However, there is some uncertainty in this information due to the potential for strong seasonal influences on these data and because of the lack of domestic metering to verify consumption on a more regular basis. The occurrence of water restrictions is one of the few 'measures' of rivers/regions under stress through water extraction. Some 22 rivers/regions are identified as being under stress during a typical dry summer.

Groundwater: In 1996 (most recent data available), groundwater use in Tasmania was estimated to be 20,000 ML/yr. This was only 4% of the total estimated sustainable yield of 500,000 ML/yr for 1995 (ARMCANZ 1996) and less than 1% of the 2,500,000 ML/yr estimate for 2000 (NLWRA 2001). It was also only 6.5% of the total major useable groundwater resources of 312,000 ML/yr (the amount within the Groundwater Management Units and not within fractured rock aquifers). However, there is uncertainty associated with the estimates of sustainable yield, because of the limited groundwater data available in Tasmania. Mineral Resources Tasmania found that only 1.7% (49) of the watertables located in 2,903 production groundwater bores across the State were at high risk of rising salinity. The watertables in 8.8% (255) of the bores were at medium risk and 89.5% (2,599) were at low risk of rising salinity.

Health and Extent of Native Riparian Vegetation: Native riparian vegetation in Tasmania is diverse in species composition and structure; however, in 1998 an estimated 1,668 km² (53%) was categorised as moderately to substantially disturbed. Many communities are poorly reserved.

Aquatic Health: Surveys show impacts to varying degrees in the biological communities in the rivers assessed. To date only a small proportion of the total extent of Tasmania's rivers has been assessed, and the focus has been on sites considered to have known or suspected problems, which creates a biased picture of the State's aquatic health. Tasmania has a higher percentage of unmodified river length than most States, with a number of sites in the South-west Wilderness World Heritage Area considered to be in pristine condition. However, as part of testing the AUSRIVAS river health models in Tasmania, an assessment of selected test sites across the State with known or suspected impacts found that the macroinvertebrate communities were impacted at nearly half of the sites.

Wetlands: Tasmania has a large number of wetlands which are diverse and widely distributed across the State. Of the State's 148 wetland sites of high conservation value, 59 are of conservation importance at a State level and 89 at a national level. Approximately 60% of the nationally important wetlands are in good or near-pristine condition. A further 281 sites are considered to have conservation significance and have been proposed for listing as important wetlands. However, at present very few listed sites have any sort of security through reservation, and in the order of 25% are declining in condition or have suffered extinctions. Information is patchy, outdated or biased towards specific disciplines (e.g. bird values), and the pre-European extent of wetlands is unknown.

Wild Rivers: A Wild Rivers assessment was undertaken in 1998 as part of a national Wild Rivers Assessment (Environment Australia 1998). Tasmania's wild rivers make up 25% of the State's rivers with a total length of 9,907 km, with the majority being in the south-west.

Land Use and Inland Waters: This Issue Report draws together the pressures and effects on Tasmania's inland waters from land use activities and management practices. There are many land use pressures on Tasmania's inland waters. They generally stem from the management practices of water extraction and storage for human uses (e.g. agriculture, drinking water and industry) and catchment land use activities like land clearing, agriculture, native vegetation conversion, industry and urbanisation.