Households with Piped into Dwelling (number)
| 2009 |
| Nairobi | 230,704 |
| Kiambu | 60,224 |
| Nakuru | 32,572 |
| Mombasa | 31,055 |
| Meru | 29,737 |
| Nyeri | 24,534 |
| Kajiado | 15,602 |
| Uasin Gishu | 15,465 |
| Kericho | 15,249 |
| Kilifi | 14,151 |
| Embu | 11,810 |
| Kirinyaga | 10,975 |
| Muranga | 10,802 |
| Machakos | 9,809 |
| Laikipia | 8,753 |
| Bomet | 7,910 |
| Kisumu | 7,653 |
| Kakamega | 6,263 |
| Nyandarua | 5,718 |
| Taita Taveta | 4,639 |
| Makueni | 4,529 |
| Bungoma | 4,186 |
| Nandi | 3,234 |
| Garissa | 3,233 |
| Kwale | 3,080 |
| Trans Nzoia | 2,822 |
| Kisii | 2,449 |
| Turkana | 2,313 |
| Isiolo | 2,010 |
| Kitui | 1,968 |
| Baringo | 1,925 |
| Elgeyo Marakwet | 1,856 |
| Siaya | 1,850 |
| Lamu | 1,732 |
| Homa Bay | 1,625 |
| Mandera | 1,426 |
| Narok | 1,401 |
| Vihiga | 1,387 |
| Migori | 1,359 |
| West Pokot | 1,210 |
| Busia | 986 |
| Tana River | 800 |
| Nyamira | 713 |
| Samburu | 441 |
| Tharaka Nithi | 328 |
| Wajir | 249 |
| Marsabit | 147 |