United States: Water deficits from CA to the Mississippi, & Eastern Seaboard

28 February 2018

THE BIG PICTURE

The 12-month forecast indicates widespread intense water deficits across much of the southern two-thirds of the nation, reaching from California to Maryland. Deficits are expected to reach exceptional severity – a return frequency of 40 years or more – in central California, western Nevada, northern Arkansas, northern Louisiana, and central Mississippi.

Primarily moderate deficits are forecast for Oregon, northeastern North Dakota, northwestern Minnesota, central Wisconsin, New Jersey, eastern Massachusetts, and Maine.

Moderate surplus conditions are forecast for southwestern Montana, northeastern Nebraska, central Michigan, and western New York. Both deficits and surpluses are expected in Washington, northern Idaho, and northwestern Montana.

Outside the contiguous US, surpluses are forecast for northwestern Alaska and the northern half of the Alaskan Peninsula, and some deficits in the eastern half of the state; surpluses are forecast in Hawai’i, which may be exceptional in the western half of the Big Island; and, moderate deficits are forecast for western Puerto Rico.

FORECAST BREAKDOWN
The 3-month maps (below) show the evolving conditions in more detail.

The near-term forecast – February through April – shows significant relief from widespread exceptional deficits observed during the prior three months in the West and the Lower Mississippi states, as deficits downgrade somewhat overall. However, deficits of varying severity remain in the forecast from California to the Mississippi, and from the Gulf of Mexico northward along the Eastern Seaboard through Massachusetts. Severe to extreme deficits may be especially pervasive in New Mexico, Missouri into central Illinois, and Virginia. Relatively normal water conditions are expected in the Great Lakes States, the Ohio River Valley, and in the Northeast. Deficits will emerge in Oregon and persist in North Dakota and northwestern Minnesota. Surpluses will continue to emerge in eastern Washington, Idaho, and western Montana and along the Missouri and Yellowstone Rivers, and may be exceptional in western Montana.

From May through July, deficits will spread in the West, and will upgrade in severity to extreme – a return period of 20 to 40 years – in central California, western Nevada, southwestern Arizona, northeastern Utah, and southwestern Colorado. Primarily moderate deficits will continue to emerge across southern states, emerging in Florida and reaching northward through Maryland. Deficits are expected to be extreme in northern Louisiana, spreading into surrounding states. Deficits in southern Illinois and in Missouri will moderate. Surpluses in the Northwest will diminish but moderate surpluses will continue to emerge in south-central Montana. Moderate surplus will also persist in northeastern Nebraska and will emerge in southern Michigan and northeastern Ohio into Pennsylvania and New York.

The forecast for the final months – August through October – indicates moderate deficits throughout much of the country with some areas of greater severity.

(It should be noted that forecast skill declines with longer lead times.)

IMPACTS
Heavy rainfall combined with melting snow is creating massive flooding throughout the Mid-West. Schools were closed and emergency shelters were set up in Elkhart, Indiana as the St. Joseph River approached its crest level in what the mayor described as the worst flooding in 45 years. In Michigan, homes and streets flooded in Flint leaving motorists and a school bus stranded; sandbags were deployed to protect properties in Mattawan; and in Grand Rapids, washout may have caused two trains to derail. Officials in Michigan are also concerned about dam safety, as flooding has compromised one spillway and pushed one dam to capacity, threatening downriver populations.

Flooding on the Ohio River left downtown Aurora, Indiana suitable for kayaking, as the river rose above the 60 foot mark for the first time in 20 years. In Cincinnati, the floodwaters crept into the parking lot of Paul Brown Stadium, home of professional football team the Bengals. Landslides were reported in Pittsburgh. At least six people have lost their lives in the devastation.

Tornadoes and torrential rainstorms ripped through the southern US, killing four people, knocking out power lines, and destroying property.

Dry weather across the Great Plains pushed wheat prices to a 4-month high at the end of January. The condition of the hard red winter wheat crop has dropped, according to the USDA, with only 4 percent of the Oklahoma crop in good condition and about 14 percent of the Kansas crop. Fire departments in Kansas are on high alert for wildfires.

As of February 14-20, the US Drought Portal reports 36.5 percent of the lower 48 states in drought, primarily from California to the Mississippi River, and parts of the Northern Plains.

In response to last month’s devastating mudslide in Santa Barbara, California county officials changed the terminology of their highest-tier disaster warning from “voluntary evacuation” to “mandatory evacuation.” At a press conference the county sheriff noted that many residents remained in their homes during the storm despite the voluntary evacuation order, seemingly having misinterpreted the urgency of the warning due to its language.

Grants totaling $34.4 million for eight desalination projects across California were approved by state water officials last month. All but one of the projects source water other than seawater, which is the most expensive to desalinate, and instead use brackish rivers or underground aquifers. Proposition 1, a water bond passed by state voters in November 2014, supplies officials with another $58 million for desalination projects.

A year after California emerged from an “emergency drought,” the state Water Resources Control Board is now debating whether and how to make permanent the state’s drought-era water restrictions. Detractors argue that the proposal may undermine California’s historic protection of landowner water rights. Under consideration are several variations of the plan, including deferring water restriction enforcement to district-level authorities. A decision is expected by mid-April.

A recent survey by the US Department of Defense on current climate-change related risk to military infrastructure reported damage to 50 percent of installations from six climate risk categories.

In its most recent report on national hazard mitigation, the National Institute of Building Sciences estimates that each $1 spent on federally funded pre-disaster mitigation grants saves society $6 in costs associated with disasters such as hurricanes and wildfires.

NOTE ON ADMINISTRATIVE BOUNDARIES
There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.

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