Today, only remnants are left of the formerly rich fauna and flora of the Rhine. Valuable communities and their habitats have been destroyed in the alluvial areas as only a fifth is left of the alluvial valley in which the Rhine may still spread. Humans currently use 80 per cent of the former floodplains. Roads and railways cross the alluvial areas behind the protecting dykes, cities and villages have spread to the fertile river plains. This inundation of the floodplains has caused flooding in the lower reaches of the river during the period of snow melts in spring. Projects to keep the river navigable, by deepening the channel and cutting off meanders, have also reduced storage areas upstream.Due to the large number of industries located on the banks of the river, as well as the potentially dangerous cargoes carried by ships on the river, chemical pollution was reaching high levels by the late 1980’s. This culminated in the disastrous fire in the Schweizerhalle pesticide chemical plant in 1986 which led to serious pollution of the Rhine. For several days, fishing activities and drinking water production had to be stopped up to 1000 km downstream in the Netherlands. Thousands of dead fish washed up on the banks of the river downstream. After this event the International Commission for the Protection of the Rhine (ICPR) drew up a Rhine Action Plan Against Chemical Pollution (view RAP). This was adopted by the European community in 1987. This imposed a strict regulating regime on industries alongside the river. It also made provision for limiting water pollution stemming from the transportation of goods on the river. For example, toxic chemicals can only be transported in double-walled vessels.Pollution from agriculture also plays a major role. Pesticides and fertilizers are applied to fields on the banks of the river and are then washed into the river by rainwater or blown in by the wind. Fertilizers have been responsible for high levels of nitrogen and phosphorous in the water. About one third of the nitrogen load discharged into the North Sea by rivers comes from the Rhine. Therefore the RAP includes strict limits on the amount and types of agricultural chemicals which can be applied to fields in the catchment.The floods of 1993 and 1995 made it clear that:floods are natural events, which must be periodically reckoned on.humans have aggravated the maximum flood level by river development and by reducing natural flood storage areas.embankments and other flood protection structures along the Rhine cannot grant absolute protection.settlements and other forms of land use in flood-prone areas present a particular damage risk.Â The Action Plan on Flood Defense (view) was signed by the ministers of the Rhine at Rotterdam in 1998. This commits â‚¬ 12 billion over the next twenty years to reduce the frequency and severity of floods in the lower reaches of the Rhine. The main component of its work is to increase the alluvial floodplain areas of the river. This will provide storage space for flood water. No new settlements will be permitted on the flood plains and several existing ones will be relocated. The plan also recognises the fact that planning must include the possibility of flooding. Its most important target is to reduce damages by 10 % by the year 2005 and up to 25 % by 2020. Extreme flood levels downstream of the regulated Upper Rhine are to be reduced by 30 cm by 2005 and 70 cm by 2020. These ambitious targets can only be reached if all flood protection protagonists cooperate closely and constructively. The hitherto practiced sector based way of thinking must be replaced by integrated planning and action on a local, regional, national and international scale. The policies related to water management, spatial planning, nature protection, agriculture and forestry are to be designed in harmony with one another.Since 1987 the levels of pollution in the Rhine have steadily been decreasing. By 1995 the amount of phosphorous and nitrogen had decreased by 50 %. Ninety percent of all urban wastewater is now treated in sewerage plants, compared to 75% in the mid 1980’s. This has had a positive impact on the fauna and flora of the river. Coupled with projects to aid fish migration, such as building ‘fish ladders’ to bypass weirs, there has been a gradual return to some parts of the river of Salmon and Sea Trout. Of course, much work still remains to be done with levels of heavy metals and some pesticides still being higher than WHO safety guidelines.