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Good practice Imported

RECONECT Tamnava River Basin — Large-Scale Nature-Based Flood Risk Reduction

Serbia · Ub · See the Serbia profile

Evidence: Descriptive / self-reported Top 40% 47/100 · Ask Evidence Copilot about this practice

EU Horizon 2020's RECONECT project modelled nature-based measures across Serbia's flood-prone Tamnava basin, finding 20-47% reductions in flood extent, volume and damage costs, with retention ponds reaching a 5.6 benefit-cost ratio once co-benefits are counted.

20-27 %
Flood area reduction (modelled) (modelled to 2100)
28-35 %
Flood volume reduction (modelled) (modelled to 2100)
40-47 %
Damage cost reduction (modelled) (modelled to 2100)
5.6 ratio
Benefit-cost ratio, retention ponds (with co-benefits) (modelled)
3.5 ratio
Benefit-cost ratio, afforestation/reforestation (with co-benefits) (modelled)
RECONECT Tamnava River Basin — Large-Scale Nature-Based Flood Risk Reduction

Details

Maturity
Pilot
Promoter
Jaroslav Černi Water Institute / RECONECT Consortium (EU Horizon 2020)
Period
2018–2021
Keywords
water management, flood risk reduction, nature-based infrastructure

Context

The Tamnava river basin (730 km2, western Serbia, Kolubara District) was repeatedly devastated by floods in 1999, 2006, 2009 and catastrophically in 2014. It was selected as a pilot site under the EU Horizon 2020 RECONECT project (grant 776866, 2018-2021), implemented locally by the Jaroslav Cerni Water Institute, to test whether nature-based solutions could substitute for or complement conventional flood infrastructure.

Activities

Researchers modelled four scenarios projected out to 2100: the existing protection system; a green scenario adding new retention ponds and floodplain restoration; a grey scenario raising levees and diverting flood discharge; and a combined green-grey scenario, alongside afforestation/reforestation and obstruction removal.

Results

Modelled results showed flood area reduced by 20-27%, flood volume by 28-35%, and damage costs by 40-47%, depending on retention pond configuration. A cost-benefit analysis found afforestation/reforestation returned a benefit-cost ratio of 3.5 and retention ponds 5.6 once five co-benefits (carbon sequestration, biological pest control, habitat creation, air pollution reduction, education) were added — turning marginally-positive flood measures into strongly positive investments.

Conclusions

These figures come from published hydrological and economic modelling, not yet from monitored outcomes of constructed works; further scale-up depends on land acquisition and municipal follow-through beyond RECONECT's research phase.

Implementation
Indicative cost
Medium (€50k–€500k) — Funded under EU Horizon 2020 grant 776866; no basin-level construction budget is reported since the project is at the research/design stage.
Time to results
Medium (1–3 years) — Three-year research project (2018-2021) modelling outcomes to 2100; construction and scale-up have not yet been reported.
Staffing & skills
Jaroslav Cerni Water Institute, local implementing research partner, RECONECT Consortium, EU Horizon 2020 grant 776866

Conditions for success

  • EU Horizon 2020 consortium funding and a named lead research institute
  • A published, replicable scenario-modelling and cost-benefit methodology
  • Counting co-benefits (carbon, pest control, habitat, air quality, education) substantially improved the investment case for nature-based measures

Common failure modes

  • Results are modelled projections, not yet monitored outcomes of constructed works
  • Further scale-up depends on land acquisition and municipal follow-through beyond RECONECT's research phase

Where it fits

Governance type
EU-funded research consortium with a national water-institute delivery partner
Scale
river-basin (730 km2)
Income level
upper-middle-income (EU candidate country)

Commonly funded by

Horizon Europe

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Data sources

Where this practice's information was retrieved from, and when.

Attachments

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