RESTORATION OF ZDWORSKIE LAKE (POLAND) - RESTORATION WORKS AND THEIR RESULTS Zbigniew Popek, Michał Wasilewicz, Agnieszka Bańkowska Warsaw University of Life Sciences (WULS-SGGW) Department of Hydraulic Engineering and Environmental Restoration ; Keszthely,,
CONTENT Introduction of Zdworskie Lake Degradation of Zdowrskie Lake Restoration work in Zdworskie Lake Measurements and analisys Results Conclusions
ZDWORSKIE LAKE - INTRODUCTION Location
ZDWORSKIE LAKE - INTRODUCTION Location www.maps.grida.no
ZDWORSKIE LAKE - INTRODUCTION Watershed total: 47,1 km 2 direct: 20 km 2 agricultural/ afforested Inflows Wielka Struga 3 periodic inflows
ZDWORSKIE LAKE - INTRODUCTION Watershed total: 47,1 km 2 direct: 20 km 2 agricultural/ afforested Inflows Wielka Struga 3 periodic inflows
ZDWORSKIE LAKE - INTRODUCTION Watershed total: 47,1 km 2 direct: 20 km 2 agricultural/ afforested Inflows Wielka Struga 3 periodic inflows
ZDWORSKIE LAKE - INTRODUCTION Morphometry: A: 343 ha V: 7 326 000 m 3 h max: 4,55 m h mean: 2,12 m Mixing and related parameters: polimictic convenient oxygen conditions (DO 100% in the water column and sediment) (estimated for normal water level 79,2 m.a.m.s.l)
ZDWORSKIE LAKE - DEGRADATION Decrease in water level of about 30 cm Mass dying of eels WZMiUW 2003 WZMiUW 2003
ZDWORSKIE LAKE - DEGRADATION Loss of water in the riverbed of Wielka Struga Drought in summer 2003 WZMiUW 2003
ZDWORSKIE LAKE - DEGRADATION Indices of lake Zdworskie water quality (2004-2005) indices (maximum values) Phosphates [mg P/L] Total phosphorus [mg P/L] Mineral nitrogen [mg N/L] Total nitrogen [mg N/L] Electrical conductivity [µs/cm] Chlorophyll a [mg/m 3 ] COD [mg O 2 /L] BOD 5 [mg O 2 /L] Secchi disc transparency [m] (minimum value) surface layer in spring 0,020 0,049 1,31 2,92 472 22,4 - - 0,7 surface layer in summer - 0,090-2,90-74,8 80,4 9,0 0,4 Based on Ocena jakości Jeziora Zdworskiego 2004 rok and Ocena ( ) 2005 rok WIOŚ; Płock 2004, 2005 According to Polish Lake Monitoring System
ZDWORSKIE LAKE - DEGRADATION High nitrogen, phosphorus and organic matter concentrations in Wielka Struga river Low phosphorus buffering capacity in sediment (low Fe/P ratio: 2,7-15,0) Small amount of crustacean zooplankton
RESTORATION WORK phosphorus inactivation broad-crested weir artificial alimentation biomass removal bales of barley straw filling the riverbed of Wielka Struga floating containers with macrophytes reintroduction of Zebra Mussel
RESTORATION WORK Broad-crested weir in the outflow for stabilising water level in the lake at the level 79.20 m.a.s.l (normal water stage) Wasilewicz 2008 broadcrested weir
RESTORATION WORK Artificial alimentation by means of pipeline connecting Dobrzykowski reservoir with the lake Outflow to the lake trough aerator Wasilewicz 2008 Flow - 45 L/s (1,5 mln m 3 /year) artificial alimentation
RESTORATION WORK Filling of Wielka Struga riverbed to provide higher discharge Material: bentonite Wasilewicz 2008 Total length riverbed of filled: 900 m filling the riverbed
RESTORATION WORK Fixation of dissolved phosphorus using FeCl 3 Application: December 2007- April 2008 permanently from August 2008 Dosage: 7,5-15 L/d Wasilewicz 2008 Wasilewicz 2008 phosphorus inactivation
MEASUREMENTS Water level and discharge Water quality Sediment characteritics
MEASUREMENTS Water level and discharge Water quality ppk 15 Water quality control points Location of water gauges Sediment characteritics
RESULTS RESTORATION OF WATER SUPPLY Inputs of water into the lake (hydrological year 2008) source Wielka Struga A B C artificial alimentation total inflow outflow m 3 965 095 18 349 2 971 2 423 1 020 600 2 009 438 680 533 % 48,03 0,91 0,15 0,12 50,79 100 33,87
RESULTS RESTORATION OF WATER SUPPLY Water level in the outflow 79,38 m.a.m.s.l. Water level [cm] Normal water level (79,2 m.a.m.s.l.) 78,92 m.a.m.s.l. Hydrological year 2008
RESULTS RESTORATION OF WATER SUPPLY Water supply from the main inflow Wielka Struga (filled) Discharge [m 3 /s] Hydrological year 2008 Specific runoff in Wielka Struga river basin 1,38 L/s*km 2 (The lowest specific runoff observed in Poland 2,53 L/s*km 2; Specific runoff in Vistula river basin 4,0 L/s*km 2 )
RESULTS LOADING AND WATER QUALITY Inputs of nutrients into the lake P A, B, C 1% N Wielka Struga 63% artifcial alimentation 36% artificial alimentation 27% Wielka Struga 72% A, B, C 1%
RESULTS LOADING AND WATER QUALITY Inputs of nutrients into the lake (hydrological year 2008) P [mg/m2] N [mg/m2] 80 60 40 20 0 39,97 2,68 0,04 0,02 N 23,07 Wielka Struga A B C artificial alimentation 2500 source 2000 1500 1000 500 0 1415,73 P 14,12 1,68 1,43 528,44 Wielka Struga A B C artificial alimentation source N 65,78 total 1961,4 total Critical load 8,97 mg/m 2 Critical load 127 mg/m 2 Critical load according to Vollenweider [Vollenweider 1976]
RESULTS LOADING AND WATER QUALITY Distribution of nutrient load in the lake P N fixation 62% outflow 13% effective load 25% outflow 14% effective load 86%
RESULTS SEDIMENTS Characteristics of sediment after and during FeCl 3 application date of measurement (distance to the inlet of FeCl 3 ) Fe [g Fe/kg w.b] P [g P/kg w.b] EPC-0 [mg PO 4 /L] Fe/P 04.2008 (5m) 0,100 0,003 1,286 33 04.2008 (10 m) 0,146 0,0031 0,692 47 05.2008 (5m) 0,101 0,0026 1,420 39 06.2008 (5m) 0,118 0,0043 0,474 27 07.2008 (5m) 0,301 0,1260 2,263 2 08.2008 (5m) 0,360 0,0304 1,890 12 EPC-0 equilibrum PO 4 3- concentration
RESULTS LOADING AND WATER QUALITY Trophic state of the lake during reclamation process (location 15) TSI-component 2004 2005 2008 TSI (TP) 69,04 63,19 60,46 TSI (chl.) 69,38 66,13 61,45 TSI (SD) 73,20 69,99 67,36 TSI 70,54 66,44 63,09 trophic status hipertrophy eutrophy eutrophy TSI trophic state index for lakes (Carlson 1977)
CONCLUSIONS Very small water resources in the Zdworskie lake drainage basin Used measures are not enough so far to maintain normal water level over the year Higher alimentation in summer/autumn period seems to be recommended For the proper recognition of water supply further measurements have to be done Reparation work caused water quality improvement in some regions of the lake However, the nutrient loading is still very high and exceeds critical load which probably reduces effects of restoration measures The phosphorus and nitrogen loading have to be reduced, otherwise no sustainable water quality improvement will be possible There is a conflict between artificial alimentation and water quality which has to be taken into account Further observations of restoration effects have to be done
REFERENCES BAŃKOWSKA A., WASILEWICZ M., 2008: Przegląd działań realizowanych w celu poprawy stanu Jeziora Zdworskiego, Przegląd Naukowy InŜynieria Środowiska, Warszawa 2008 GLINKA A., PRTKIEWICZ S., MARCINIAK W., 1994: Koncepcja rozbudowy systemu dopływowego z przepompowni Dobrzyków. Odcinek Ludwików - Jezioro Zdworskie. Gostynin 1994; maszynopis JEZNACH J., BAJKOWSKI S., 2006: Opinia funkcjonalności urządzenia do eliminacji zakwitów sinic na Jeziorze Zdworskim, SGGW w Warszawie, Warszawa 2006; maszynopis JĘDRYKA E., MACIEJEWSKI S., 2007: Rekultywacja Jeziora Zdworskiego. Część 2 MoŜliwości rekultywacji. Wiadomości melioracyjne i łąkarskie, t. 50, nr 2 POPEK Z., WASILEWICZ M., BAŃKOWSKA A., 2008: Monitoring jakości i ilości wód zasilających Jezioro Zdworskie. Sprawozdanie końcowe. Warszawa 2008 POPEK Z., WASILEWICZ M., BAŃKOWSKA A., 2008: Ocena wpływu aeratora falowego na jakość wód i osadu dennego w Jeziorze Zdworskim. Sprawozdanie końcowe. Warszawa 2008 CARLSON R.E., 1977: Trophic state index for lakes. Limnology and Oceanography. 22:2 361--369 Koncepcja renaturyzacji Jeziora Zdworskiego, Biuro Konsultacyjne InŜynieria Środowiska, Warszawa 2005 Dokumentacja geologiczna określająca warunki hydrogeologiczne dla Doliny Wielkiej Strugi. Zakład Badań i Robót InŜynieryjnych GEOBAD, Słupno 2006; maszynopis Ocena Jakości Wód Jeziora Zdworskiego w roku 2004, WIOŚ Płock, Płock 2004 Ocena Jakości Wód Jeziora Zdworskiego w roku 2005, WIOŚ Płock, Płock 2005 Wojewódzki Zarząd Melioracji i Urządzeń Wodnych Oddział w Płocku WZMiUW o/płock, 2007: materiały niepublikowane Wyniki badań jakości Jeziora Zdworskiego w roku 2006. PROTE Technologie dla Środowiska Sp. z o.o.; maszynopis Wyniki badań osadów w dnie Jeziora Zdworskiego w gm. Łąck, pow. płockim dla potrzeb jego renaturyzacji. Zakład Badań i Robót InŜynieryjnych GEOBAD, Słupno 2006; maszynopis
RESTORATION OF ZDWORSKIE LAKE (POLAND) - RESTORATION WORKS AND THEIR RESULTS Zbigniew Popek, Michał Wasilewicz, Agnieszka Bańkowska Warsaw University of Life Sciences Department of Hydraulic Engineering and Environmental Restoration THANK YOU FOR YOUR ATTENTION ; Keszthely,,