Wet and wonderful

Dinneen's famous Irish-English dictionary, compiled in a world more attentive to nature, had many words for different sorts of wind (even the "perilous, magical wind" that blew from some unimaginable quarter). There were far fewer terms for rain, except in how hard it poured. Under bais, however, the heaviest sort of rain, it offers a typically evocative usage: bais doibe buidhe ar iochtar an chota, "a layer of yellow mud on the extremity of the coat."

At the time of Father Dinneen's dictionary, compiled around a century ago, the roads were indeed very muddy but the rain was falling on a very different island. Away from the big estates it was almost treeless, but still covered for most of the year with knee-high vegetation. The hills were cloaked in heather, mosses and moorgrass, the lowland fields in their native grasses, mown once a year for hay.

Rain took its time in filtering away to the streams. In the lowlands there were marshes, fens and lakes where it lingered on its way to the rivers and the sea. This slow percolation produced water of a crystal clarity, and stable aquatic habitats full of minutely-adapted wildlife. There were pearl mussels in the rivers, Arctic charr in the lakes, both now threatened or extinct.

With the storage and slow release of water, even the seasonal floods rose gently and within fairly predictable bounds. In a saucer-shaped country, with the Shannon as an almost level gutter down the middle, they were inevitable - and remain so.

The arterial drainage of Ireland, which reached its peak in the late 1900s, was an engineers' crusade, aiming to get water off the land and down to the sea at the maximum rate of cubic metres per second. In almost 40 catchments, river beds were brutally dredged into a trapezoidal U-shape and the banks clawed back to the steepest angle the local clays would sustain. Spoil was dumped into handy ponds and marshes, or left heaped on the banks like miners' waste. These and other schemes, as David Cabot summed up in his recent Ireland: A Natural History, "have physically destroyed countless wetlands, particularly turloughs, many of which were important wildfowl and botanical habitats. River habitats, including fish spawning beds and river banks, important for breeding birds and many invertebrates, have also been destroyed or severely disrupted." The Millennium Report of the Environmental Protection Agency confirms that the drainage "has in many cases resulted in damage to areas of scientific interest and to fish stocks."

The EU, as so often, has funded conflicting aims from different pockets, helping regional drainage on the one hand and setting exacting wildlife standards on the other. But its proposed Water Framework Directive now arrives with an ambitious confluence of aims.

It intends each river basin to be managed so that there is enough high-quality water for "sustainable development", but also for protection of all the water needs of terrestrial and aquatic ecosystems. And in enforcement of protection, the polluter will pay.

The structure for all this will be a complex ecosystem in itself - a challenge indicated by the acronyms lined up behind next month's big seminar on "River Basin Management" in Tullamore, Co Offaly. It is organised "by the Irish national committees of the IHP and ICID in association with the IEI, ACEI, IAH, CIWEM and BHS". (Presumably they all know who they are, but it's the Office of Public Works that wants participants to pay £185.)

Inherent in this holistic gathering of hydrologists, geographers, engineers, environmental scientists, planners and social scientists is a change in the technocratic approach to the natural life of a river and its tributaries. Scientists and geomorphologists have been modelling the effect on flow of organic river features - bends and meanders, shoals and deeps, leaning willows, fringes of bulrushes - in the effort to shape new formulae that both engineers and ecologists can accept.

Since 1990, the drainage engineers of the OPW have been working with the Central Fisheries Board to examine the impact of their standard "channel maintenance" and to experiment with other ways of digging that do the natural river corridor less harm. Four years ago, a new programme was extended to all the channels managed by the OPW - one that lets rivers have an asymmetrical bed, creating "hydraulic diversity" and habitats that older trout can live in.

In the prime angling catchments of the Moy and Corrib, the regional fisheries boards (with European co-funding) have gone a lot further in restoring lowland streams dug out in the drainage schemes of the 1960s. They have brought back the natural "valley" that streams carve in their beds, and natural sequences of riffle, glide and pool; they have provided willow-shade and places for fish to hide beneath banks with plants and insects.

Such a painstaking tribute to the natural regime finds an echo in next month's seminar. Wetlands are back in technocratic esteem - not just as a habitat for otters and waterfowl, or even as a buffer zone between the run-off of heavy rain and the gathering of a flood. The kind of reed swamp that laid the foundations for the raised bogs of the midlands is now seen as a living engineering tool for filtering and purifying waste of all kinds, including human sewage and slurry.

SPECIALLY constructed wetlands planted with reeds and sedges are already in use in the Anne Valley Project, in Co Waterford, where polluted farmyard water ends up pure enough for trout to live in. Commercial reed-bed systems are becoming an acceptable alternative to septic tanks and offer a natural way of restoring polluted fisheries. Researchers from NUIG will brief the Tullamore seminar on evaluating how well they work.

Since the middle 1800s, the total area of Ireland drained under various Acts and schemes amounts to more than 2 million hectares. The cost to nature and the landscape has often been unnecessarily high. The new EU Directive gives ecology its proper place in long-term planning to keep our rivers safe, clean, and beautiful as well.

The "River Basin Management" seminar will be held in the Tullamore Court Hotel on November 21st. Details are available from Mark Adamson, OPW, 17-19 Lower Hatch Street, Dublin 2. E-mail: mark.adamson@opw.ie.