Many physical problems that are modeled by the Shallow Water Equations benefit from being represented in a one-dimensional approach. Problems where there is one preferred direction, such as in the flow in a river or a channel, are often solved using this approximation due to the computational advantage that it offers. Therefore there exists a vast scientific literature devoted to 1D hydrodynamic models with additional characteristics, such as variable density, sediment or pollutant transport or erosion, to cite a few [1, 2]. Networks can be built by connecting each of these domains in junctions, which add a new challenge to the model. Current junction methods work well in the subcritical regime but fail as the flow accelerates, and are in general unable to deal with critical transition and unsteady transition to supercritical regime flows which often occur in catastrophic free-surface flows. Therefore other approaches are needed, such as coupling one-dimensional to two-dimensional local models at the junction [3]. This contribution showcases a model for the Junction Riemann Problem (JRP) which manages to tackle the problem in all regimes while maintaining the compromise between quality of the numerical results and computational efficiency. It is based in the advanced Junction Riemann Problem formulation developed in [4] for blood vessels. Using this approach, a non-linear system of equations is solved iteratively at the junction. It is formed by energy and mass conservation and the wave invariants. This technique includes new restrictions that allow the solution of this system to be found in all hydraulic regimes. REFERENCES [1] C. Juez, J. Murillo, and P. Garc´ıa-Navarro, “One-dimensional riemann solver involving variable horizontal density to compute unsteady sediment transport,” Journal of hydraulic engineering, vol. 142, no. 3, p. 04015056, 2016. [2] S. Martínez-Aranda, J. Murillo, and P. García-Navarro, “A 1d numerical model for the simulation of unsteady and highly erosive flows in rivers,” Computers & Fluids, vol. 181, pp. 8–34, 2019. [3] F. Bellamoli, L. O. Müller, and E. F. Toro, “A numerical method for junctions in networks of shallow-water channels,” Applied Mathematics and Computation, vol. 337,pp. 190–213, 2018. [4] J. Murillo and P. García-Navarro, “A solution of the junction riemann problem for 1d hyperbolic balance laws in networks including supersonic flow conditions on elasticcollapsible tubes,” Symmetry, vol. 13, no. 9, p. 1658