About Percolark: Watershed Steward
Guide a tiny watershed through a sequence of storms. Percolark: Watershed Steward is a 3D planning puzzle about rainfall, finite soil storage and channel runoff. Choose Sealed, Meadow, Woodland or Rain garden surfaces for three to five plots, then keep every storm’s runoff at or below its stated limit within a limited intervention budget.
Your plan is set before the storms begin. Every surface choice updates a deterministic forecast, letting you inspect how much water enters the soil, runs to the channel and drains to groundwater between storms. Soil water carries over, so a plan that handles the first storm can still struggle with a later one.
Explore 180 studies across Small Catchments, Storm Sequences and Saturation Strategy. Compare the end-of-plan diorama with each storm’s numeric ledger, revise a surface, undo an edit or ask for a hint toward a satisfying plan that preserves as many of your current choices as possible. Every plan meeting the budget and all runoff limits is accepted.
The game uses explicit fictional units and coefficients to make water accounting visible. It tracks quantity, not sediment, pollution, drinking-water safety or real flood predictions. Infiltration moves water into storage; the full balance counts initial soil water and rainfall against final soil water, channel runoff and named groundwater drainage.
Earn up to three stars per study and revisit earlier challenges to improve your best result. Best stars, course position and sound preference save on this device when browser storage is available.
How to Play Percolark: Watershed Steward
Choose Small Catchments (Easy), Storm Sequences (Medium) or Saturation Strategy (Hard). Each course has 60 studies. Easy uses three plots and two storms, Medium uses four plots and three storms, and Hard uses five plots and three storms.
Read the intervention budget, each plot’s base soil capacity and initial stored water, and every storm’s rainfall and channel-runoff limit. Select a plot and choose a permanent surface before the storm sequence. Sealed costs 0, Meadow 1, Woodland 2 and Rain garden 3 points. Editing a choice recalculates the whole forecast from the initial conditions.
During each storm, infiltration is the smallest of rainfall, the cover’s infiltration limit and the soil’s remaining capacity. The rest is channel runoff. Meadow and Woodland allow up to 2 units to infiltrate per storm; Rain garden allows up to 4; Sealed allows none. Woodland adds 2 capacity units and Rain garden adds 1.
Only between storms, Meadow and Woodland drain up to 1 stored unit to groundwater, while Rain garden drains up to 2. Sealed has no drainage. There is no gap drainage after the final storm. Water left in soil carries into the next storm. Groundwater is a separate destination; its later flow lies outside the model.
Inspect any storm’s ledger and the end-of-plan forecast. Meet every runoff limit within budget, then Check watershed plan. Undo edit revisits a cover change, Reset covers restores Sealed on every plot and Field hint suggests one change without applying it. Unsuccessful checks and hint use remain recorded after Undo edit or Reset covers.
Desktop: A–E selects an available plot; 1 chooses Sealed, 2 Meadow, 3 Woodland and 4 Rain garden. Left and Right arrows inspect storms. Enter checks the plan or continues after success, Z undoes a cover edit, R resets covers, H requests a field hint and M toggles sound. Escape closes help. Tab and Enter activate focused on-screen controls normally.
Mobile: select a plot using the 3D catchment or plot buttons, then tap a cover card. Tap a storm to inspect its forecast and ledger. The diorama always shows final soil water after all storms, while the ledger shows the selected storm. Use Undo edit, Reset covers, Field hint, Check watershed plan and the sound control.
Earn three stars with no unsuccessful checks or hints, two stars with up to two unsuccessful checks and no hints, or one star for any completed study. Reset and undo keep check and hint history. Over-budget plans stay editable but cannot be checked until their cover cost is reduced. Your best result is retained when replaying a study.