We learn about hydrologic cycle during our elementary schooling and then most of us get busy with our lives doing things that completely depends on water, but we typically tend to forget or wishfully ignore the way our water demands are met by the present day water infrastructure. Nature recycles water for all of us at very little or no direct monetary cost to us, but can we afford the time nature takes to return the water we use today? Water plays such a vital role in our everyday life that we cannot afford to ignore our nations' aging water infrastructure, changing sources, status quo operations, complex sociological issues, and their interactions that affect how we do water in the 21st century. One of the biggest limitations of our current water infrastructure is its design that allows us to use the highly purified water only once before returning it back to the nature for future reuse. Population growth resulting in increased demand for water and changing weather pattern resulting in extreme drought and flooding conditions are stressing our nation's aging water infrastructure. It is prime time for water professionals to rethink the fundamentals of water infrastructure design such that the 21st century water infrastructure can withstand both the pressures from growing demand and changing climate. Two fundamental shifts are happening in water industry albeit slowly but steadily that should be encouraging to the society: first is to consider "One Water" infrastructure instead of fragmented waters such as drinking water, waste water, and storm water; and second is to integrate "reuse" of once used or unwanted water (aka waste water or storm water) in the water infrastructure. The era of using highly purified drinking water only once is over, we just can't afford to discharge adequately treated wastewater into rivers or groundwater anymore because of the time and unpredictable path nature takes to return that water back to our source water supplies. Advances in water treatment science and technologies made in the 20th century allow us to refurbish existing and build new water infrastructure to use once captured water at least four or more times; and after that return a small amount of absolutely unusable water back to a controlled environment that is hydrologically not too far from our source water supplies. Reuse of water both at large municipal scale and small individual dwelling scale has been successfully demonstrated at various locations, however full-scale integration of reusing water onsite in an existing water infrastructure is still only a concept. A research, demonstration, and education program called Sustainable and Integrated Water Infrastructure (SiWi) is underway at Texas A&M University to increase awareness for water reuse. This paper will present overview of the Onsite Water Reuse (OWR) concept and give details on opportunities and challenges related to integration of this concept into our current water infrastructure to make it SiWi compatible. The authors of this paper will also recruit members to serve on the newly formed Onsite Water Reuse subcommittee (NRES-262) whose goal is to develop and promote standards for OWR as they relate to SiWi.