Despite the extremely high rainfall in 2017, construction works in the Kampinos National Park are continued. The designed network of small hydrotechnical objects has been partially built or is still under construction as part of the LIFE12 NAT / PL/000084
In the Impact Area of Wilcza Struga, located in the western part of the Kampinos Forest, the causeway in Sadowa village is one of the most important objects. It is a causeway of anti-flooding importance, separating the wetlands of the Kampinos Woodland from the meadows of Sadowa (Fig. 1).
Fig. 1 Panoramic view of the Sadowa causeway. On the left side of the causeway is the Kampinos National Park, on the right the meadows of the village of Sadowa. Water level in KPN is clearly higher than in the meadows of the village of Sadowa. October 2017
In addition to this object in the Impact Area of Wilcza Struga, fords with a stacking function (Fig. 2), culverts and valves with a damming function (Fig. 3) have been built.
Fig. 2 Ford with a damming function in the area of Wilcza Struga. This structure is intended to stop low water levels, while during high levels the flow should not be distupted. February 2017
Fig. 3 Typical barrier in a ditch, October 2017, fot. A. Andrzejewska
Four culverts and a ditch were built in the Żurawiowe Impact Area. All these facilities are designed to allow the inflow of more water to the Żurawiowe Protection Area.
Works in the impact areas of the Canal Zaborowski and Canal Dolna Łasica, located in the western part of the Kampinos Woodlands, mainly include small objects with damming function. Most of the hydrotechnical construction in the Dolna Łasica Impact Area are currently under water, which makes it almost impossible to continue works.
Record rainfall in the second half of 2017
In the autumn of 2017, the continuation of works was suspended due to the unusually high water level in the Kampinoski National Park. Month by month, the increasing precipitation measurements surprised us more and more (Fig. 4). By the end of October 2017 804 mm of rain fell in the Kampinos Woodlands (based on measurements from the rainfall station in Izabelin) which gives 133% of the average annual rainfall (from the years 2000-2017).
Fig. 4 Graph of precipitation totals in the years 2000-2017 in the period from January to October (based on measurements from the rainfall station in Izabelin)
In some areas, especially in the western part of the Kampinos National Park, the water level is so high that the construction company that started work in this area in August was forced to stop it because most of the construction sites can not be reached. It is a responsible approach, as the use of heavy construction equipment on ground roads could cause deterioration of the condition of roads used also by the residents of neighboring villages.
Fig. 5 A graph comparing the monthly sums of rainfall from 2017 to the average monthly rainfall sums from the years 2000-2017.
In September, 173 mm of rainfall fell, which resulted in exceeding the average monthly rainfall for September by 135 mm. In October, high rainfall was still a problem - 112 mm fell, which gives a 75 mm higher rainfall than the average rainfall for the month of October (Fig. 5). It caused rising level of the Łasica Canal (Fig. 6). This is an exceptional situation, not yet recorded by employees of the Kampinos National Park.
Fortunately, the danger of flooding of this meadow area has been detected in advance - thanks to the precise digital elevation model. The Kampinos National Park has successfully applied for the extension of land purchase zones located in this lowering of land from private owners.
Fig. 6 Brochów Łąki, area located in the depression, high water level condition from the October 25, 2017. View from the Sianno weir towards the south-west. Fot. M. Wojciechowicz