Pregnant/Lambing Ewes drowning in creek

Hi, we've just started renting in a rural property which has a fair amount of waterways that are not fenced and some areas are boggy which results in the pregnant/lambing ewes being caught in the mud and drowning as a result. While we are not working the farm so while it isnt our responsibility its not too nice to see all the dead ewes and lambs and the farmers dont appear to be too concerned about it just letting the bodies decay away. We are on spring water/bore and a lot of the dead sheep are in the waterways so not sure how this affects drinking water. Apparently certain regulations require waterways to be fenced (New Zealand here) and not sure these are being abided by but don't want to cause waves as we will need to find another rental accommodation. I am going to go and dig out a bit of a drain surrounding spots where sheep are being drowned and see if that helps the situation a bit - only a temporary solution though. Winter has just been and caused the creek to flood and now in spring the sheep seem to be being attracted to waterplants (watercress?) growing in the streams which leads them in to a quicksand sort of environment. The farmers just leave the quite large number of dead ewes and lambs to just rot which can get over but really dont like the idea of pregnant or lambing ewes drowning while the lambs are next to them and that sort of thing. Thought about planting bamboo or reeds to prevent access but the sheep probably will eat these (bamboo I know until high enough anyway) and dont want to make the issue worse by attracting them into bad areas. Can anyone offer any suggestions? Thanks

Contact the local authorities and see what they think about the contamination of the local water.  Not all farmers are good farmers.