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.
Additional Examples
In the last few years, several hypothetical scenarios were tested using the above-specified subroutine to evaluate the performance of the drywell. (Sasidharan et al., 2020a) compared the performance of drywell and infiltration basin, and a representative example project for infiltration basin (Infiltration Basin 1) can be downloaded below. (Sasidharan et al., 2020b) conducted numerical experiments to systematically study the influence of various homogenous soil types and subsurface heterogeneity on recharge from drywells under constant head conditions. A representative example project for homogenous (Drywell 5) and stochastic (Drywell 6) domains can be downloaded below. Additional numerical simulations were conducted to understand the virus transport from drywell, especially in the presence of subsurface heterogeneity (Sasidharan et al., 2021), and a representative example (Drywell 7) can be downloaded below. Mathematical description for the HYDRUS simulation runs described in Sasidharan et al. (2021), the direct computational modules (h2d_calc_virus.exe), and additional information on projects can be downloaded below.
|
Project
|
Description
|
|
Infiltration Basin 1
|
A representative example project for infiltration basin
|
|
Drywell 5
|
A representative example project for a drywell in a homogenous domain
|
|
Drywell 6
|
A representative example project for a drywell in a heterogeneous (stochastic) domain
|
|
Drywell 7
|
A representative example conducted to understand the virus transport in a drywell system (the computational module).
|
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.
- Sasidharan, S., S. A. Bradford, J. Šimůnek, and S. R. Kraemer, Drywell infiltration and hydraulic properties in heterogeneous soil profiles, Journal of Hydrology, 570, 598-561, doi: 10.1016/j.jhydrol.2018.12.073, 2019.
- Sasidharan, S., S. A. Bradford, J. Šimůnek, and S. R. Kraemer, Groundwater recharge from drywells under constant head conditions, Journal of Hydrology, 583, 124569, 14 p., doi: 10.1016/j.jhydrol.2020.124569, 2020a.
- Sasidharan, S., S. A. Bradford, J. Šimůnek, and S. R. Kraemer, Comparison of recharge from drywells and infiltration basins, Journal of Hydrology, 125720, 13 p., doi: 10.1016/j.jhydrol.2020.125720, 2020b.
- Sasidharan, S., S. A. Bradford, J. Šimůnek, and S. R. Kraemer, Virus transport from drywells under constant head conditions: A modeling study, Water Research, 197, 117040, 14 p., doi: 10.1016/j.watres.2021.117040, 2021.
Acknowledgment
Partial 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).