Summary:

The most significant problem in contemporary climatology - climate warm-ing. Although not confirmed beyond any doubt, still numerous factors indicate climate change within the recent, relatively short period of time. In studies con-cerning the role of forest cover in the water balance of catchments researchers stressed considerable retention capacity of forested areas. This capacity influences an increased total runoff from catchments with higher forest cover in dry years and its reduction in wet years, as well as increased runoff in summer half-years and its reduction in winter half-years. In research on catchments with different
degrees of forest cover they showed high retention capacity of catchments with
a higher forest cover. This is evidenced by very uniform courses of monthly flows and relatively limited monthly changes in retention. Also in long-term studies con-ducted by the Department of Water Management, the Forestry Research Institute, under conditions found in lowland catchments a stabilizing effect of forest cover may be observed on water runoff from the area of the catchments, mainly a reduc-tion of its uneven distribution. Nowadays wetlands belong to one of the most threatened ecosystems. They are important biodiversity hot spots, habitats for pro-tected and endangered plant species and natural reservoirs for water retention. In order to save this vulnerable ecosystems people started to protected them and or-ganized active conservation. For a few years The State Forests implemented the project which shows how the small retention can be use as a tools for conserva-tion. The term so-called small water retention defining all interventions having in view extension way and time of circulation of water in catchments. Usually this is understanding as stopping and dam up waters in water-courses and accumulation her in water reservoirs. To small retention belong water reservoirs about entire capacities < 5 million m3. Activities in range of small retention serve to improve-ment of water balance in catchments across enlarging of supplies discretionary waters. Determine also important element of protection of waters quality. The Forest Inspectorate/Division Kolumna is a part of The Regional Directorate of the State Forests in Łódź. It's located in its central part. It manages 20,000 ha of for-ests and supervises 6,000 ha of private forests. Territorial range of the forest in-spectorate comes to 1,342 km2. Dominant species in the forest stand are Scots pine. The forest habitats comes to 50% of the Forest Inspectorate. The areas are poor of natural water reservoir and rivers. The forest habitats are located in
a short distances to brown coal mine in Bełchatów. This situation has a negative influence on water relations. Recently on many areas of the Forest Inspectorate Kolumna equipments of small water retention are worked out. Many new
construction of small water retention will be appeared in future. For example
a surface water will enlarge to about 40 ha - new water reservoirs (lake,
ponds etc.).