Aquifer Storativity

09/05/25

“How can we quantify the volume of water an aquifer is likely to release when there’s a change in head pressure?”

Wells pull water up from aquifers through pressure head reduction. But every aquifer is different, and we need to quantify how much water a formation is likely to release per pressure head reduction. Luckily, we have a parameter called Aquifer Storativity that measures the amount of water released per area to a given change in pressure head. For confined aquifers, storativity is equal to the specific storage times the aquifer thickness.

Aquifer Transmissivity

09/04/25

“How can we quantify the transmissive capabilities of an aquifer system?”

When water is pumped out of an aquifer, the aquifer’s properties will determine how fast and how much water will come to the well pump. The rate at which an aquifer can horizontally transmit water is called Aquifer Transmissivity. Aquifer transmissivity is measured in area per time unit, proportional to the product of the aquifer’s hydraulic conductivity and saturated thickness.

Aquifer Drawdown

09/03/25

“What happens to an aquifer’s pressure head when a well is inserted?”

Inserting objects into an aquifer will change its properties. When a well is inserted, the groundwater’s hydraulic head is reduced. The closer a piece of groundwater is to the well, the more it is reduced. This decrease in pressure is known as Aquifer Drawdown. Aquifer drawdown is important for completing aquifer water production field tests.

Spillways

09/01/25

“How can we release water from a dam when it’s too full?”

Dams and reservoirs hold a certain amount of water. When there’s too much water, it can damage the dam and the surrounding area. So what if we were to design a mechanism that allows us to release a certain amount of water before overflow occurs? Well, this is the idea behind Spillways. Spillways come in all shapes and sizes and are a fundamental part of many water containment infrastructure systems.

Cloudburst Hubs

08/24/25

“How is New York City using modern planning and engineering techniques to adapt to cloudburst flooding events?”

Cloudbursts release a voluminous amount of rain in a short amount of time, which can cause widespread damage to people and infrastructure. New York City is taking an innovative approach to protecting against these events through its Cloudburst Hubs. Cloudburst hubs are hydraulically connected areas in NYC that are vulnerable to deep flooding and can also include infiltration, storage, and conveyance to reduce the flood depths of hotspots, connect onsite with right-of-way strategies, including diverting street runoff, and use a combination of green-grey strategies to mitigate against floods. These cloudburst hubs can help city residents adapt to the new climate paradigm. 

Image credit: https://www.nyc.gov/

How to Calculate Power for Hydraulic Pumps

08/20/25

“How do we calculate power for hydraulic pumps?”

Hydraulic pumps are a pillar of modern water infrastructure. Through their mechanisms, they can create a pressure differential to match the needs of people. But pumps need power to operate, and we may need to calculate the power to accomplish what our goals. To do this, we can go to the simple physics equation (1) work = force * distance (W = F * h). Going further, we may notice that if we’re lifting a fluid, the force will be equal to (2) the fluid’s mass * gravity (m_fluid * g), and (3) mass of fluid = density of fluid * volume of fluid (m_fluid = rho_fluid * V_fluid).  This is related to power through the equation (4) P = dW/dt, where Power is P. We can plug in equation (1) to (4) to make (5) P = d(F * h)/dt. → dF/dt*ht. If we substitute in equation (3), we get (6)  P =  (d(rho_fluid * V_fluid*g)/dt*h), and by (7) fluid flow = change in fluid over time (Q = dV_fluid/dt), we can substitute for (8) P = rho_fluid * g * h * dV_fluid/dt → P = rho_fluid * g * h * Q. And by remembering that (9) specific weight = density of fluid * gravity (Gamma_fluid = rho_fluid * g), we can finalize with (10) P = Gamma_fluid * Q * h. This is How to Calculate Power for Hydraulic Pumps. The pump’s efficiency will also affect this value.

Manning’s Roughness Coefficient

08/19/25

“How can we measure the resistance to fluid flow in channels and floodplains?”

Fluids flow through open channels in conduits and floodplains. The structures supporting fluid flow provide resistance to movement. The structure’s base surface roughness, stage and discharge, obstructions, geometric irregularities and alignment, vegetation, and debris contribute to fluid resistance. These are quantitatively summarized by Manning’s Roughness Coefficient, a variable vital for channel flow calculations. Manning’s roughness coefficients for various materials are found in engineering reference manuals.

Ponding

08/17/25

“What happens when water has no place to drain?”

Water will collect over land when there are insufficient infiltration capabilities. If this water has no place to drain, it will coalesce into a sizable puddle. This Ponding process can produce small bodies of water that can carry pollutants, become mosquito nesting grounds, and even damage building structures if it collects on a small roof.