A snowy winter improved Poland’s groundwater situation, but not enough to lift the country’s hydrogeological threat warning, Małgorzata Woźnicka, an expert with the Polish Geological Institute, has said.
Hydrologists say groundwater recovery is helped by landscape retention, including small field ponds, peatlands, natural depressions, and blue-green infrastructure in cities.
They also point to the need to limit paved surfaces and reduce groundwater use by reusing gray water where possible.
Woźnicka told Poland's PAP news agency that groundwater levels in some areas remain below low warning thresholds.
She said such a shortage can occur naturally in autumn after summer, but should not be present in spring.
“In spring, a low-water period should not occur,” Woźnicka said.
The warning follows a dry March and April, low forest-floor moisture, and strong winds that created a critical fire risk in Polish forests.
The conditions contributed to a major forest fire in the southeast of the country earlier this month.
The drought has also hit agriculture. In early May, some agricultural chambers called for municipal commissions to assess drought-related losses, after drying soil led some farmers to abandon crops.
The Institute of Meteorology and Water Management (IMGW) also reported unusually low spring water levels in rivers and lakes, with 74 percent of Polish rivers at low levels.
Experts distinguish between several types of drought. Meteorological drought is linked to a lack of rainfall, agricultural drought affects soil and crops; hydrological drought concerns rivers and lakes; and hydrogeological drought affects groundwater.
Woźnicka said Poland’s documented usable groundwater resources amount to 34 million cubic meters a day.
On average, the country uses about 22 percent of its renewable groundwater resources each year, which she described as safe at national level.
Local problems can still occur, especially where water is drawn for mining or from unregistered sources.
Woźnicka said field researchers have seen an increase in unrecorded groundwater use linked to agricultural drought. In some regions, estimated unregistered water extraction may equal 50 percent of officially recorded use.
Groundwater is a key source of drinking water in Poland. Around 85 percent of the country’s 21,000 registered groundwater intakes supply drinking water, and 74 percent of water distributed by waterworks for drinking purposes comes from underground sources.
Woźnicka said deep groundwater intakes used by municipal companies are usually resistant to short-term rainfall shortages.
A lack of tap water does not necessarily mean a groundwater source has dried up. It may instead reflect overloaded water networks or infrastructure failures.
"Cities and smaller towns have increasingly dispersed buildings, and therefore longer water supply networks," Woźnicka said. "At the ends of networks, water pressure is much lower, which is why taps may run dry when water use rises."
Ecohydrologist Sebastian Szklarek said that by early May he had recorded more than 50 municipal appeals asking residents to stop watering lawns and filling swimming pools.
In one municipality, he said water use in early May was so high that the waterworks struggled to keep up, even after accounting for emergency reserves.
Shallow groundwater sources, such as individual wells, dug wells, and so-called Abyssinian wells, are more vulnerable to prolonged drought.
Experts say Poland needs to retain as much rainwater and meltwater as possible in the soil.
Woźnicka said hydrogeologists sometimes say that a drop of water that reaches a river is a lost drop, because it flows toward the sea instead of replenishing groundwater.
She said groundwater renewal depends most on long-lasting, moderate rain over larger areas, as well as snowy winters and spring thaws.
More annual rainfall does not automatically mean groundwater resources will recover more effectively.
Sudden, localized downpours after long dry spells often run quickly into drainage systems in concrete-covered cities, while parched soil in green areas struggles to absorb water.
A hydrologist warned last year that Poland could soon experience the worst drought in its recorded history, not only due to climate change but also as a result of poor water management and a lack of sustained rainfall.
(rt/gs)
Source: PAP