The Multipurpose functional category covers a variety of USACE assets that fulfill multiple authorized purposes that may include flood risk management, water supply, hydropower generation, navigation, recreation, and environmental restoration. USACE hydropower infrastructure falls under the Multipurpose functional category; therefore, for the purposes of this study, all hydropower facilities are accounted for under the Multipurpose functional category.

Simple observations on the calculated capital stock value covered under the Multipurpose functional category are as follows (values in 2021 $):

• The rate of investments made in this stock, starting in 1936, exhibited a steady growth through the mid-1950s, increasing at an average rate of 6.7% annually from 1936 through 1953. Annual investment peaked in 1953 at $6.3 billion (in 2020 dollars). Since 1953, annual investments in 2020 dollars have declined at an average rate of 2.8% annually.
• The peak USACE Multipurpose capital stock value of $102 billion occurred in 1980. Since 1980, annual deterioration in the estimated capital stock has exceeded investments.
• The average rate of decline from 1980 to 2021 was 2.7% annually.
• The 2021 USACE Multipurpose capital stock value is $29.8 billion, or approximately what it was between 1950 and 1952 and about 29% of its peak 1980 value.

By 1986, most large multipurpose projects had already been built, were in the process of being built, or had already been rejected on economic or environmental grounds. Additionally, projects that might have been approved in the past would now be rejected because of cost-sharing requirements, budgetary pressures, or environmental impacts.