Saturday, 15 December 2012

Draining Jeziorki - then and now

Jeziorki, being as flat as Lincolnshire and of poor soil quality, has been subject to localised flooding whenever the water table has risen above the surface after heavy rains. Crops are vulnerable, and as Warsaw began spreading out into the surrounding fields, with new houses beginning to appear, they too were liable to flooding.

So from the early post-war years, a system of retention ponds (zbiorniki retencyjne) were built, absorbing water fed into them by a network of drainage ditches. The largest the one between ul. Trombity, Kórnicka and Dumki (see map below). This map is from 1993, but the shape of the pond is unchanged from the 1958 map. What happened over the years, what the maps didn't show, was that the pond shrank, as reeds took over and soil washed into its basin from the drainage ditches raised the level of its bottom. And landowners blocked the drainage ditches, into which domestic rubbish was also dumped, leaving  them unfit for purpose and increasing the incidence of local flooding (podtopienie).

Until the major work on the reclaiming the ponds began earlier this autumn, the outline of the pond looked nothing like on this map. Not shown on the map is the drainage ditch that acts as the southern border of Warsaw, running along the dotted black line at the bottom of the map. Let's follow it from west (as it crosses ul. Gogolińska and the Warsaw-Radom railway line) to ul. Puławska.

Above: between the railway line and the old Rampa na kruszywa. The border of the ditch is secured by fascines woven from willow branches. Below: the channel (przepust) under the old trackbed of the Rampa escarpment. Note the dumped household waste; apparently some brudasi still consider this a good place to dispose of their old kitchen furniture. And note the weeds taking hold. If left unchecked, this state of affairs will lead to a blockage of the channel, and the flooding on ul. Gogolińska will get worse.

Walking the length of this ditch, I can imagine the work that went into it, after the war, precious little heavy plant on hand (all was needed for the rebuilding of Warsaw); hard physical labour which had real sense - saving one's neighbours' fields from regular flooding. For many young men across what was then the Warsaw Voivodship (now Mazovian), this would have been their first paid work after six years of war (forced labour or fighting with the underground); the joy of a pay-packet mingled with the fear of new repressions from a new occupant.

Left: the ditch runs on, to the left, Mysiadło, to the right, Warsaw. When work on this drainage system commenced, Warsaw extended south only as far as Służewiec and the horse-racing track. Ursynów was incorporated into the City of Warsaw's boundaries in 1951; this ditch has marked its southern border for the past six decades. An unsung piece of civil engineering gets a long-overdue hat-tip.

Above: a lateral channel ( 52° 6'13.42"N,  21° 0'53.80"E) running into the ditch from ul. Pozytywki. Below: a sluice gate slightly further along.

Below: the ditch reaches ul. Puławska, immediately behind me as I take the photo. Note the metal grating under the footbridge, in front of which lies washed-up vegetation. This needs to be removed periodically if the channel is not to be blocked.

Below: the course of the drainage ditch is marked in blue on this Google Earth image, dated 1 May 2012.

There are many other drainage ditches in Jeziorki. After 60 years, the field drainage system is currently being subject to a massive refurbishment, starting with the main retention ponds. The six-million zloty investment should ensure that for the foreseeable future, we'll not be threatened with flooding.

This time last year:
The Eurocrisis - what would Jesus do?

This time three years ago:
Orders of magnitude

This time three years ago:
Jeziorki in the snow

This time four years ago:
Better news on the commuting front

This time five years ago:
I no longer recognise the land where I was born


Anonymous said...

Michael - a very interesting post!


Michael Dembinski said...

Thanks Bob - I'm surprised I didn't write about this sooner. Maybe had the works to deepen our local ponds not got under way, I might have not considered drainage a subject worthy of a blog post!