The recent grip of a multi-year drought in California and the western part of the United States has highlighted just how previous water is as a resource. Which states have the highest percentage by area of perennial water and which states have the lowest amount of perennial water?

The USGS has consolidated a table with the area of each state that covered by water from data provided by the U.S. Census Bureau’s table: Geography: State Area Measurements, 2010. The statistics from both tables calculates the amount of area for each state and the District of Columbia that is covered by perennial water. These calculations don’t include water from intermittent, glacier, and and marsh/swamp sources.

Overall, the United States has 264,837 square miles of water, accounting for 7% of the total area of the country. The state with the largest total area of water is Alaska, which has 94,743 square miles of water. The state with the second largest total area is Michigan, a distant second with 40,175 square miles. Percentage wise, however, Michigan ranks as the number one state with 41.5% of its total area occupied by water. Hawaii, with 41.2% of its total area water-based, is a close second. Alaska’s percentage of area that is water is only 14.2%.

The driest states are found mostly in the mid-west and western part of the country. New Mexico, Arizona, Colorado, Kansas, Nevada, Wyoming, Nebraska, Iowa, and West Virginia all have less than 1% of each state’s total area as water.

Tile-grid Map Showing Percentage Water Area Per State

The tile-grid map (see how to make a Tile Grid Map using Excel) below shows which states are the driest (light grey and light blue) and which states are the wettest (medium and dark blues). Only three states have 30% or more water area: Rhode Island, Michigan, and Hawaii. On the dry side, thirty states have less than five percent water area.

This chart shows how the states stack up in terms of percentage area that is water:

Table: Land Area and Water Area of Each State and the District of Columbia

This sortable table shows the total land area and water area of each state and the District of Columbia. You can sort in ascending and descending order for any of the columns by clicking on each column header; the arrow icon next to each column name indicates the sort order.