Two species of salamanders are joining the ranks of species listed for protection under the Endangered Species Act (ESA).

One, the Austin blind salamander, will be listed as endangered while the other, called the Jollyville Plateau species, will be listed as threatened.

The decision came as a result of a settlement in 2011 of a lawsuit by environmental groups against the US Fish and WIldlife Service (FWS), according to a report by the NPR project State Impact.

According to the FWS, the salamanders are entirely aquatic and depend on water from the Edwards Aquifer for survival. The site represents one of the most prolific artesian aquifers in the world, serving "diverse agricultural, industrial, recreational, and domestic needs of almost two million users in south central Texas," EdwardsAquifer.net reports.

As regional demand for water has increased over the past few decades, many wildlife groups, including the Center for Biological Diversity, have grown increasingly concerned regarding the animals that call the aquifer home. With the designation of the salamanders as protected under the ESA, however, comes a designation of 4.450 acres of critical habitat for both species -- a decision that will restrict developers from construction in what is, according to WRAL, one of the fastest growing urban areas in the state.

Chris Herrington is a member of the City of Austin's Wastershed Protection Department, which has been working with the FWS to keep the pool where the Austin blind salamander lives open and the small animal protected. In total, Herrington told State Impact that he and his group have never spotted more than 1,000 of the salamanders during their counts.

Meanwhile, the FWS says it is postponing any decision in regards to two other salamanders known as the Georgetown and Salado salamanders for six months, and is reopening for public comment for the next 30 days.