I’ve lived in the District for almost 30 years and have witnessed the changes that The Post examined in its stories last month on millennials and “the New Washington.”

My daily commute from Mount Pleasant to Chinatown takes me past neighborhoods transformed by the growing number of people in their 20s and 30s moving in. Whole Foods and Harris Teeter markets seem to be everywhere. And it’s not my imagination that there’s a new condo building on every corner: More than 1,200 apartments and condominiums have been built or put on the market in the 14th Street corridor in the past year, according to The Post.

We should consider what has been lost in this transformation: the longtime families who were pushed out of their neighborhoods as wealthier residents moved in.

Our transitioning neighborhoods are gaining single young residents, but they have also lost more than 13,000 youths and elderly people in the past decade, according to a recent study for the D.C. Tax Revision Commission. Displaced families sent their kids to local schools, kept church pews full and wove a fabric of life that made the District a home town.

When I walk along 14th Street NW today, I often think about these lost families.

I remember a woman I met about 10 years ago, when she was being evicted from her S Street home. She and her children were renting the house with support from a Section 8 voucher, but it was no longer being accepted by many Logan Circle landlords because they realized they could charge higher rents. My organization worked to slow the eviction and give her time to find a safe place.

The eviction had many repercussions. The woman lost easy access to the neighborhood grocery store, a critical link to fresh food in a town pocked with food deserts. Her kids were transferred from Garrison Elementary to a new school, and she struggled to find quality, affordable after-care to replace the program she lost. And she had to say goodbye to the friends and neighbors who kept an eye on her house during the day.

Families like hers lost more than their houses to make way for the New Washington. They lost a community of support.

The District lost out, too, by not doing more to help vulnerable families stay in their neighborhoods. This woman was an active and caring person in her community, raised her boys to be good men and was committed to her local schools. Such residents were the first wave that made these places more attractive for those who came later.

Our city leaders need to do a better job of figuring out how to make the New Washington work for everyone. Focusing on affordable housing would be a good start. The District’s housing boom has cut the availability of low-cost rentals in half since 2000, according to the D.C. Fiscal Policy Institute. Tens of thousands of people are on the waiting list for rental assistance from the D.C. Housing Authority, which is no longer accepting new applications. Imagine what it would mean to struggling families if even 2 percent of those 1,200 new condos on 14th Street had been set aside for low-income residents.

Everyone wants to bring more revenue to the District and to live in vibrant, safe neighborhoods. But why does our growth mean that so many low- and moderate-income families have to leave? And where are they all going to go when there’s no affordable housing left?

I’m tired of all the talk about the New Washington and the Old Washington. Let’s focus on creating One Washington that works for us all.

The writer is the executive director of Children’s Law Center.