As Colorado cities struggle with a shortage of inexpensive homes, witnesses at a U.S. Senate hearing this week said the problem will only get worse unless the federal government intervenes soon.

By 2025, about 15 million people nationwide will spend more than half their incomes on rent if home prices continue to rise at the current rate, compared with about 12 million now, according to a Harvard University housing policy study. Few of them would ever be able to save enough money to purchase a home.

The Senate Finance Committee held the hearing as it considers legislation to expand the Low-Income Housing Tax Credit (LIHTC) by 50 percent. The program gives real estate developers and investors billions of dollars in tax credits to build housing for low-income residents.

Witnesses from government agencies and private industry said the number of renters has been increasing as fast as home prices.

“This is both an urban and rural problem,” said Sen. Maria Cantwell (D-WA), a co-sponsor of the Affordable Housing Credit Improvement Act of 2017. “There are places like Jackson, Mississippi and Baton Rouge that are just right up there with Miami and … there’s places like Clarke [County], Iowa and Douglas [County], Nevada. It’s everywhere.”

The LIHTC has played a role in about 90 percent of low-income housing built in recent years.

The bill Cantwell and co-sponsor Orrin Hatch, R-Utah, proposed would provide economic incentives to build or preserve about 1.3 million affordable homes in the next decade, or 400,000 more than anticipated under the LIHTC.

Affordable housing normally is defined as housing that would cost persons with a median household income no more than 30 percent of their earnings.

Section 8 of the U.S. Housing Act refers to a program that authorizes government payment of rent to private landlords for about five million low-income households. It is administered by the U.S. Department of Housing and Urban Development (HUD).

Supporters of Cantwell’s proposed legislation include housing advocates nationwide along with many Republicans and Democrats in Congress.

One of them is Sen. Michael Bennet, D-Colo., a member of the Senate Finance Committee.

“Michael has met families across the state who are struggling with the high costs of housing, whether it’s access to rental communities or owning a home,” said a Bennet spokesperson. “On the federal level, he supports efforts to increase the amount of low-income housing tax credits available for states and local governments, which can increase the supply of affordable housing.”

However, a government auditor from the U.S. Government Accountability Office warned at the hearing that some of the money from the current $8.5 billion a year LIHTC program is hard to track, raising suspicions about whether it is wasted.

“[The Internal Revenue Service] and no one else in the federal government really has an idea of what’s going on,” said Daniel Garcia-Diaz, the GAO auditor.

The IRS often found improprieties among the 58 state agencies it audited for compliance with the LIHTC program since the program started 30 years ago, Diaz said.

“Because little information was captured in the Low-Income Housing Credit database, IRS was unable to provide us with program-wide information on the most common types of noncompliance,” he said in his statement to the Senate. “Furthermore, IRS had no method to determine if issues reported as uncorrected had been resolved or if properties had recurring noncompliance issues.”

Grant Whitaker, president of the National Council of State Housing Agencies and the Utah Housing Corporation, said the strengthening of the housing market in recent years has come at a high price for low-income households.

The National Association of Realtors reported that first-time homebuyers accounted for 32 percent of home purchases in June, compared with a historical average of 40 percent.

“Even as the housing market strengthens, many creditworthy homebuyers, especially first-time buyers, struggle to obtain mortgages they can afford,” Whitaker said. “As more and more people turn to the rental market, they find a severe shortage of affordable homes.”

Colorado cities suffer affordable housing shortages similar to the scenarios described during the Senate hearing, which prompted Denver Mayor Michael Hancock to develop one of the nation’s most active programs for combating the problem.

In June, he announced on Facebook that the city would reach its goal this summer of building 3,000 affordable housing units a year earlier than originally planned. They consist of 2,865 apartments and 149 for-sale affordable homes.

“We’re not stopping there,” Hancock said.

Denver is in the process of building another 1,500 affordable housing units in 16 developments across the city, Hancock said.

Most of them are located in parts of Denver where gentrification is transforming neighborhoods and raising home prices.

“We’re doing everything we can to keep the pedal to the metal,” Hancock said.

Colorado Springs is set to open 240 affordable housing units in the fall but still needs more, according to city officials. They are developing a mapping tool to help real estate developers apply for federal funding to build affordable housing.

“Community Development is collaborating with the City’s [Geographical Information System Department] to add mapping layers that will make available high level overviews of key neighborhood characteristics, such as job concentrations, percentages of homeowners versus renters, age of the housing stock and household income levels,” Steve Posey, City of Colorado Springs HUD program administrator, told Colorado Politics. “The information is being drawn from multiple sources and consolidated into a simple graphic format.”