drainage is the only way to get rid of rushes im afraid mate, as long as the ground is still wet they will return. there are thousands of seeds in each plant and the can lay dormant in the soil for around 70 years.
theres a company in Mayo that does a new type of filtered drainage pipe that works really well in peat/boggy soil. the pipe is more expensive than the normal corrugated pipes but there is no need for any stone with these. so works out about the same price as normal tile drains or a little cheaper. just dig open the trench, put pipe in and close again, really handy.
this is t