| Alfbach | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Germany |
| Subdivision Type2: | State |
| Subdivision Name2: | Rhineland-Palatinate |
| Subdivision Type3: | Reference no. |
| Subdivision Name3: | DE: 26284 |
| Length: | 22.254 km |
| Source1 Location: | Northeast of Buchet |
| Source1 Coordinates: | 50.2641°N 6.3585°W |
| Source1 Elevation: | ca. |
| Mouth Location: | West of Pronsfeld into the Prüm |
| Mouth Coordinates: | 50.1585°N 6.3328°W |
| Mouth Elevation: | ca. |
| Basin Landmarks: | Villages: Buchet, Bleialf, Pronsfeld |
| Custom Label: | References |
The Alfbach is a 22.3adj=midNaNadj=mid, orographically right-bank tributary of the Prüm in the county of Bitburg-Prüm in the German state of Rhineland-Palatinate.
The Alfbach rises in the Schneifel at a height of . Its source lies on the northern slopes of the Schwarzer Mann about three kilometres northeast of Halenfeld in the municipality of Buchet.
The stream flows initially in a southwesterly direction to Halenfeld, where it collects its main tributary, the Donsbach, then turns south as far as Buchet, before changing direction to the southwest to continue through Bleialf. Near Großlangenfeld it changes its direction again to the south and, at the Hauscheid Mill (‘’Hauscheider Mühle’’) passes under the A 60 motorway. Continuing mainly in a southeasterly direction the Alfbach empties into the Prüm west of Pronsfeld at a height of .
The Alfbach drains a catchment area of ; its waters flowing via the Prüm, Sauer, Moselle and Rhine to the North Sea.
| Name[1] | Left/right tributary | Length [km] | Catchment [km<sup>2</sup>] | Mouth elevation [m above NHN] | Mouth location Coordinates | GKZ | |
|---|---|---|---|---|---|---|---|
| Alfquelle | right | 1.123 | 0.652 | 561 | 50.2663°N 6.3434°W | 26284-12 | |
| Große Quelle | left | 0.895 | 0.242 | 536 | 50.263°N 6.3365°W | 26284-132 | |
| Alfbachgraben | left | 1.120 | 0.353 | 532 | 50.2625°N 6.3347°W | 26284-14 | |
| Lange Alfquelle | left | 1.662 | 0.644 | 514 | 50.2602°N 6.3274°W | 26284-16 | |
| Mombach | right | 1.422 | 1.448 | 508 | northeast of Halenfeld 50.2597°N 6.325°W | 26284-18 | |
| Donsbach | right | 4.177 | 6.068 | 489 | in Halenfeld 50.2554°N 6.3154°W | 26284-2 | |
| Steinbach | left | 1.280 | 2.202 | 476 | near Niederlascheid 50.2476°N 6.3145°W | 26284-32 | |
| Dürenbach | right | 2.967 | 3.915 | 452 | in Bleialf 50.2393°N 6.2971°W | 26284-4 | |
| Sonnenbach | right | 0.674 | 0.742 | 441 | south of Bleialf 50.2331°N 6.2852°W | 26284-52 | |
| Üchenbach | left | 3.607 | 4.215 | 439 | south of Bleialf 50.2318°N 6.284°W | 26284-6 | |
| Waleschbach | right | 0.663 | 0.625 | 434 | southwest of Bleialf 50.2285°N 6.2776°W | 26284-712 | |
| Lautersbach, auch Laubertsbach | right | 0.387 | 0.323 | 432 | 50.2252°N 6.2749°W | 26284-714 | |
| Katzenbach | right | 1.195 | 1.468 | 425 | near Großlangenfeld 50.2206°N 6.2719°W | 26284-716 | |
| Eisbach | left | 1.975 | 1.484 | 421 | west of Brandscheid 50.2161°N 6.2784°W | 26284-72 | |
| Eisbach | right | 1.362 | 0.971 | 418 | west of Brandscheid 50.2139°N 6.2797°W | 26284-7312 | |
| Tunenbach | right | 1.869 | 1.236 | 407 | northeast of Habscheid 50.2007°N 6.2833°W | 26284-7314 | |
| Hollbach | right | 2.776 | 2.907 | 404 | northeast of Habscheid 50.1967°N 6.2848°W | 26284-74 | |
| Paulsgraben | right | 0.618 | 0.442 | 403 | east of Habscheid 50.1921°N 6.289°W | 26284-7992 | |
| Waldgraben | right | 0.591 | 0.290 | 394 | east of Habscheid 50.1884°N 6.2999°W | 26284-7994 | |
| Vierenbach | left | 2.601 | 3.469 | 390 | east of Habscheid 50.1853°N 6.3084°W | 26284-8 | |
| Schinnbach | left | 2.393 | 1.631 | 387 | east of Habscheid 50.1827°N 6.311°W | 26284-92 | |
| Schwarzbach | left | 1.538 | 1.008 | 387 | southeast of Habscheid 50.1817°N 6.3138°W | 26284-94 | |
| Bosborn | right | 0.985 | 0.690 | 381 | southeast of Habscheid 50.1756°N 6.3161°W | 26284-96 |