Through September, The Pittsburgh Water and Sewer Authority has invested over $65 million in our Capital Improvement Projects program. As our spending reports indicate, the water distribution system spending is a significant focus of the capital improvements in 2021. By committing funding to rehabilitate and replace our water infrastructure, we are providing better services to our customers. The 2020 Small Diameter Water Main Replacement continues to be our largest water-related program this year, with over $29 million spent on the program through the end of August. PWSA strategically determines these small diameter pipe replacement projects as areas that are aged and in need of repairs. Using prioritization techniques, our team outlines plans to target locations throughout our service area that need improvements. Aside from our Small Diameter Replacement program, we have ongoing initiatives focused on lead service line replacements, large diameter water main improvements, and our water relay programs, among many others. In addition to our water program, PWSA is investing significantly in our sewer and stormwater systems.
With 25,000 catch basins in our service area, the 2020 and 2021 Catch Basin and Inlet Replacement program is an important part of our CIP that focuses on their strategic replacement. They are the first point of entry for stormwater flowing from our streets into the sewer system. By replacing these assets, we are improving the reliability of our sewer system and providing better control of stormwater. We are advancing several sewer rehabilitation programs, including the Small Diameter Pipes, Large Diameter Pipes, and the Sewers Under Structures programs, to improve the reliability of our sewer system. The Capital Improvement Projects graphic below shows a financial breakdown through 2021.