We all live in catchments and how that catchment behaves is often down to us. So this final episode is a wake up call and it takes place in a catchment that's the focus of so much national concern - the lower lakes and Coorong at the end of the Murray Darling system.

In this penultimate part of the series we gather the thoughts, concerns and fears of people living in catchments under stress. Some of these people are dealing with too much water as their homes face inundation if a new dam is built, others used to take their river allocation for granted, but now face complete uncertainty. In one catchment a local bemoans the loss of what made her community attractive in the first place.

Michael and Helen travelled to the Qld sugarcane region around the Burdekin River. In wet season, this river handles a massive amount of water that empties onto the Great Barrier Reef. In dry, the Burdekin calms down to a sedate pace. Cane growers have relied on both the river and groundwater to sustain their crops, but the water table is rising, salt water is intruding, and agricultural run-off is affecting water quality. We meet growers and soil scientists first hand.

Dams - they're vital in many communities to supply water for domestic and agriculture. However building one is not always as straight forward as it appears. In this report Michael Mackenzie takes a closer look at the Traveston Crossing Dam project which is planned for the Mary River in Queensland.

With an uncertain water future, can we risk continuing to plant permanent crops like citrus and grapes? Irrigators like Robert Mansell and Warren Lloyd have inherited a long time family tradition, and would rather not work the land at all if they couldn't do what they're doing. Both men know there's something inherently wrong with the way we allocate water, but both also believe growers like them should be given the quota to continue.

The scarcity of water in many catchments has brought old resentments bubbling to the surface between managed investment schemes and family farms, who accuse the corporates of not being true horticulturalists, receive too many tax concessions, and buying up water that should be left to the environment. One company, Timbercorp, responds by acknowledging they've made mistakes in their community relations in the past, but there are some good things about their soil and water management that smaller irrigators could learn from.

While trees are good for the environment they do compete with other agricultural enterprises for water. Visit one of the country's biggest plantation timber regions at South Australia's Mt Gambier to find out what's happening there.

For some places around the country it's almost too late to save them. Nothing lives or grows in the acid sulfate soil and waters of Bottle Bend Lagoon, an oxbow lake that only connects to the main river when the water rises high enough. That hasn't happened for awhile.

No part of any catchment typifies the decades of policy neglect and mismanagement more than the lower lakes and Coorong in South Australia. This is where the water-starved Murray River empties into Lake Albert and Lake Alexandrina. But the catchment is in crisis, with lack of inflow, upstream allocation and demands for drinking water all putting pressure on the delicate balance between freshwater and saline, bird and fish life, not to mention farms and communities. Take a glimpse into a catchment in dire need of detox.

Meet a highly successful macadamia farmer, Martin Brook from Brookfarm, Bangalow, who discovered a small remnant of rainforest on his property. In twenty years he's planted thousands of trees and the area of rainforest has grown substantially. He's also learnt a lot about the value of owls and the importance of maintaining a healthy ecosystem in order to build a sustainable farm.