HYDRUS Projects – Drywell
Drywells are increasingly used for stormwater management and enhanced aquifer recharge, but only limited research has quantitatively determined the performance of drywells. Numerical and field scale experiments were, therefore, conducted to improve our understanding and ability to characterize the drywell behavior (Sasidharan et al., 2018). In particular, the Reservoir Boundary Condition in HYDRUS (2D/3D) (Šimůnek et al., 2018) was modified to simulate transient head boundary conditions for the complex geometry of the Maxwell Type IV drywell (i.e., a sediment chamber, an overflow pipe, and the variable geometry and storage of the drywell system with depth; see the figure below) from which water can infiltrate into the soil profile.
Falling-head infiltration experiments were conducted on drywells located at the National Training Center in Fort Irwin, California (Figure A) and a commercial complex in Torrance, California (Figure B) to determine in situ soil hydraulic properties (the saturated hydraulic conductivity, K s , and the retention curve shape parameter, 𝛼) for an equivalent uniform soil profile by inverse parameter optimization.
The experimental data were analyzed using the non-standard computational modules compatible with Version 2.x of HYDRUS (2D/3D) as described in Sasidharan et al., 2018. The HYDRUS simulation runs described in Sasidharan et al. (2018), the direct and inverse computational modules (h2d_calc.exe and h2d_clci.exe, respectively), and the mathematical description of the problem, as well as of the additional required input file Well.in can be downloaded below.
References
- Sasidharan, S. A. Bradford, J. Šimůnek, B. DeJong, and S. R. Kraemer, Evaluating drywells for stormwater management and enhanced aquifer recharge, Advances in Water Resources, 116, 167-177, doi: 10.1016/j.advwatres.2018.04.003, 2018.
Acknowledgment
Funding for this research was provided by the U.S. Environmental Protection Agency (US EPA) through an interagency agreement with the United States Department of Agriculture (EPA DW-012-92465401; ARS 60-2022-7-002 ).