Saturday, 25 May 2013

Rainy night in Jeziorki tests new retention ponds

"It rained and it rained/Both night and day" [John Lee Hooker, Tupelo]. Not a biblical downpour that would have had Noah reaching for his hammer, but steady, uninterrupted, heavy rain that lasted over 16 hours. Yesterday evening, rain water was rising up the drive, by this morning the front garden was inundated.

The amount of water that fell on our property was similar to that experienced in the Corpus Christi storm of 3 June 2010. This was no cloudburst, no thunder or lightning, no tempestuous winds, just hour upon hour of heavy rain - the equivalent, we were warned, of a month's rainfall in a single day.

Yet another anomalous weather event; a good opportunity to see how the new retention ponds have fared. Their task - to prevent flooding of local houses, roads and fields. I set off by bike to inspect the neighbourhood and how it's been affected by the rains.

Above and below: certainly looking around the nearby fields, there's been a good deal of podtopienie (localised flooding). Many of the fields around ul. Trombity have had their level raised by humus dredged from the bottom of the pond. It seems not to have done the trick.

Below: the road itself is relatively dry; there's no long stretch of submerged asphalt as there was in June 2010, nor are the spur roads (ul. Dumki and Trombity 24) too badly affected.

Below: the same spot, 4 June 2010 - a massive difference; here the renovated retention ponds have proved their worth.

Below: at the end of ul. Trombity, looking along the drainage ditch running parallel to ul. Kórnicka; brim-full of rainwater. The bottom end of the field immediately behind me (between Trombity and the railway line) is flooded, as usual. The new retention ponds have done little or nothing to protect the most vulnerable fields; my advice would be to dig more drainage ditches and make existing ones wider and deeper.

A similar story by the retention ponds along ul. Pozytywki (below). The fields are flooded, the road is dry...

...and the retention pond has swallowed the rainwater, its banks are dry and secure. Note the turf that has been planted at the water's edge. Starting to look quite attractive around here!

Below: Wąsal pond, between Pozytywki, Katarynki and Czarkowskiego. Again, it's been edged with new turf, and as we can see, it's nowhere near full. [Panoramic photo - two pics merged into one.]

Below: most important proof that the renovated ponds are working (at least as far as protecting roads and buildings - as we can see fields are still liable to flooding). Looking north along ul. Puławska, towards the junction with Karczunkowska. Three years ago, that security guard box in the foreground had floated off into floodwater, and Puławska was a river from one side to the other.

Below: ul. Puławska on the morning of 4 June 2010...

In terms of preventing this kind of catastrophe, the newly-renovated ponds have done their job well. Let's just hope they will not be put to a greater test by anomalous weather events in future. However, better drainage of fields into the ponds would do our local farmers a great favour. Despite the millions of zlotys that have been spent on flood prevention in Jeziorki, the lower-lying fields remain vulnerable.

This time last year:
Wide-angle under Pl. Wilsona

This time two years ago:
Ranking a better life

This time three years ago:
Questions about our biology and spirituality

This time four years ago:
Paysages de Varsovie

This time five years ago:
Spring walk, twilight time

1 comment:

student SGH said...

Some two miles south from Jeziorki, in Nowa Iwiczna, scale of flooding is incomparably lower than in memorable June 2010. New draining ditches dug along ul. Krasickiego and revamped system of rainwater drainage have done their job well, very few fields and street were under water, houses in which basements of garages were flooded were also sparse. But after all Friday night's rainfall brought much lower precipitation the two consecutive huge downpours from 2010 - but such weather events happen once in several decades, so the real test, statistically, won't come soon