Two Wells, Two Opposite Answers: Hydraulic Head in Salty Groundwater

There Are Two Concentrations, and They Are Not Equal

The Well Doesn't Have to Reach the Salt: Upconing and the Rate Nobody Measured

Which Way Does Groundwater Actually Flow? Flatter Than the Map Says

Sinkholes, Caves and the Aquifer Where Darcy's Law Fails

What Is an Aquifer? Not a Lake, Not a River, Not a Cave

Why Coastal Wells Turn Salty So Suddenly: The 40-to-1 Rule

Porosity vs Permeability: Why a Rock Won't Give Up Its Water

How Old Is Groundwater? Some of It Fell 30,000 Years Ago

The Lake Los Angeles Drank: Mono Lake and the Water Balance

How Do You Measure an Aquifer You Can't See? The Pumping Test

Why Sand Drains Far Faster Than Silt: The Permeameter Test

The Groundwater Science Behind 'A Civil Action'

Can Grain Size Predict How Fast Water Flows? The Sieve Test

How Much of Your Soil Is Empty Space? Measuring Bulk Density

Why Water Stops at a Layer of Gravel: How Soil Really Drains

Porosity vs Permeability: Why a Rock Won't Give Up Its Water [older version]

What Is an Aquifer? Not a Lake, Not a River, Not a Cave [older version]

John Snow and the Broad Street pump: what the story gets wrong

How to Remove a Sea With Arithmetic: the Aral Sea

Why Jakarta Is Sinking: Effective Stress, Clay, and a Capital That Moved

Hydrofracking Uses "Considerable" Water — Compared to What?

Heating a greenhouse with groundwater — and the well hydraulics that follows

Mono Lake: what happens when you change one term in a water balance

Water movement in the soil: texture, compaction, layering and the capillary barrier

The Pumping Test: Running It, and Getting T and S Out of It

The Permeameter Lab: Constant Head and Falling Head, Start to Finish

Sieve Analysis, Start to Finish: the Apparatus, the Arithmetic and the Curve

Soil Bulk Density: The Core Method, Step by Step

Porosity vs Permeability: Why a Floating Rock Makes a Terrible Aquifer

What Is an Aquifer? Not a Lake, Not a River, Not a Cave