Forecasting Water Supplies for Birds and Communities

Sadly, the times when I’m most likely to get a peek at the Platte River are only when I’m crossing over it on I-80, driving to or from the many meetings where I sit in a room and talk to people about the Platte River. But on my way home from one of those meetings right after Labor Day, I saved time to spend the night on the shores of Lake McConaughy. It may seem strange to count this giant reservoir as part of the Platte River, but it is truly integral to this river system and everything that it supports downstream. And right now, Nebraska’s largest reservoir is currently sitting only a quarter of the way full, near the record-low levels measured in 2004. Certainly there was an abundance of sandy beach available to pitch a tent - but also an eeriness when imagining the immense volume of water that previously held that space.

Lake McConaughy was built in the 1940s to store water when North Platte River flows were running high in the spring and to make that water available later in the year, when summertime supplies were lower than what farmers needed for irrigation. Today, water stored in the reservoir serves many purposes, including irrigation, power production, community water supplies, recreation, and environmental needs. And the amount of water available in the reservoir is closely tied to what happens much farther upstream. Snowpack that accumulates in the Rocky Mountains of Colorado and Wyoming over the winter is one of our best indicators of how much water will flow into Lake McConaughy and eventually downstream along the Platte.

Deciding when and how much water to release from Lake McConaughy is therefore a big job—and one that involves many partners. Historic agreements provide guidelines for how the reservoir is to be operated, but balancing water needs during prolonged drought requires broad collaboration.

A small but vital portion of the water stored in Lake McConaughy is dedicated to an Environmental Account, which is used to support threatened and endangered species and their habitat on the Central Platte. Those releases help sustain the Platte River ecosystem throughout the year, not just during spring crane migration. Apart from Environmental Account and irrigation operations, streamflow released from Lake McConaughy in the winter and early spring help maintain the river and its food web, supporting the aquatic life, insects, and plants that cranes depend on. When more than a million Sandhill Cranes arrive in spring, healthy river flows also provide open channels where cranes can safely roost at night, giving them an early-warning system for predators and helping them conserve precious energy for migration. The benefits don’t stop with cranes as a recent economic analysis shows that the spring Sandhill Crane migration supports a $28M ecotourism industry along the Central Platte. (see page 9 for details)

But climate change is adding another layer of complexity. Longer and more severe droughts are expected to become more frequent, particularly in the western Platte River Basin. Because water shortages affect both people and ecosystems, we need to think ahead about how to avoid crossing over critical ecological and socioeconomic thresholds from which recovery becomes increasingly difficult.

That’s why Audubon and our VESPR partners (Vision for an Ecologically Sound Platte River) are planning a climate-focused scenario planning process beginning in late 2026 and continuing into spring 2027. By bringing together people who understand the needs of agriculture, power production, communities, wildlife, and the river itself, we can explore a range of possible futures and identify actions that help build resilience. Tools like scenario planning – that unveil some clarity in the clouds of uncertainty that we and our partners make decisions under – are our best means of forecasting how to balance future water needs for birds and people.