Least Reliable Water Systems in Colorado — 2026

Out of 658 ZIP codes with data in Colorado, these are the lowest-ranked areas for reliability score. See also: National Least Reliable Water Systems in America | All Colorado Rankings

Statistic	Value
ZIP codes ranked	658
Lowest value	10/100
Median value	75/100
State	Colorado

100 Lowest-Ranked ZIP Codes

Rank	ZIP Code	City	State	Reliability Score	Safety Score
1	81058	Manzanola	CO	10/100	33/100
2	81050	La Junta	CO	15/100	35/100
3	81092	Wiley	CO	15/100	45/100
4	81041	Granada	CO	18/100	50/100
5	81023	Beulah	CO	20/100	45/100
6	81030	Cheraw	CO	20/100	33/100
7	81426	Ophir	CO	20/100	54/100
8	81137	Ignacio	CO	21/100	62/100
9	80816	Florissant	CO	23/100	66/100
10	80487	Steamboat Springs	CO	25/100	67/100
11	80540	Lyons	CO	25/100	35/100
12	81044	Hasty	CO	25/100	37/100
13	81047	Holly	CO	25/100	33/100
14	81067	Rocky Ford	CO	25/100	45/100
15	81069	Rye	CO	25/100	40/100
16	81089	Walsenburg	CO	25/100	44/100
17	81090	Walsh	CO	25/100	34/100
18	81419	Hotchkiss	CO	25/100	57/100
19	81435	Telluride	CO	25/100	59/100
20	81321	Cortez	CO	27/100	66/100
21	81615	Snowmass Village	CO	27/100	66/100
22	80133	Palmer Lake	CO	28/100	66/100
23	81144	Monte Vista	CO	28/100	73/100
24	80465	Morrison	CO	30/100	56/100
25	80747	Peetz	CO	30/100	51/100
26	80758	Wray	CO	30/100	58/100
27	81049	Kim	CO	30/100	58/100
28	81055	La Veta	CO	30/100	53/100
29	80421	Bailey	CO	32/100	69/100
30	80818	Genoa	CO	32/100	46/100
31	80861	Vona	CO	32/100	61/100
32	81045	Haswell	CO	32/100	61/100
33	81654	Snowmass	CO	32/100	56/100
34	80136	Strasburg	CO	33/100	63/100
35	81430	Placerville	CO	34/100	65/100
36	81649	Red Cliff	CO	34/100	71/100
37	80439	Evergreen	CO	35/100	42/100
38	80454	Indian Hills	CO	35/100	62/100
39	80517	Estes Park	CO	35/100	54/100
40	80536	Livermore	CO	35/100	34/100
41	81064	Pritchett	CO	35/100	49/100
42	81324	Dove Creek	CO	35/100	47/100
43	80728	Fleming	CO	37/100	65/100
44	80744	Ovid	CO	37/100	61/100
45	80118	Larkspur	CO	38/100	60/100
46	81432	Ridgway	CO	38/100	41/100
47	80467	Oak Creek	CO	40/100	68/100
48	80537	Loveland	CO	40/100	49/100
49	80538	Loveland	CO	40/100	54/100
50	80545	Red Feather Lakes	CO	40/100	61/100
51	80860	Victor	CO	40/100	56/100
52	80863	Woodland Park	CO	40/100	59/100
53	81019	Colorado City	CO	40/100	57/100
54	81328	Mancos	CO	40/100	56/100
55	81424	Nucla	CO	40/100	60/100
56	81429	Paradox	CO	40/100	49/100
57	81434	Somerset	CO	41/100	67/100
58	80135	Sedalia	CO	42/100	64/100
59	81124	Capulin	CO	42/100	82/100
60	81623	Carbondale	CO	44/100	68/100
61	81252	Westcliffe	CO	45/100	55/100
62	81326	Hesperus	CO	45/100	46/100
63	81423	Norwood	CO	45/100	55/100
64	81643	Mesa	CO	45/100	64/100
65	80476	Silver Plume	CO	46/100	67/100
66	80483	Yampa	CO	46/100	79/100
67	81071	Sheridan Lake	CO	46/100	62/100
68	80459	Kremmling	CO	47/100	65/100
69	80727	Eckley	CO	47/100	61/100
70	80737	Julesburg	CO	47/100	61/100
71	80832	Ramah	CO	47/100	69/100
72	81054	Las Animas	CO	47/100	61/100
73	80621	Fort Lupton	CO	48/100	61/100
74	80654	Wiggins	CO	48/100	57/100
75	80101	Agate	CO	49/100	64/100
76	80301	Boulder	CO	49/100	58/100
77	80302	Boulder	CO	49/100	53/100
78	80303	Boulder	CO	49/100	53/100
79	80304	Boulder	CO	49/100	53/100
80	80305	Boulder	CO	49/100	58/100
81	80310	Boulder	CO	49/100	64/100
82	80549	Wellington	CO	49/100	63/100
83	81652	Silt	CO	49/100	64/100

Methodology

Water system reliability scores (0-100) combine violation frequency, violation recency, resolution rate, and system size. Systems with repeated health-based violations and unresolved issues score lowest. The reliability score focuses specifically on the water utility performance, distinct from the broader Home Safety Score.

Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-04-13.

Frequently Asked Questions

What does a low water reliability score mean?

A low reliability score (below 50) indicates a water system with frequent violations, poor resolution rates, or recurring compliance issues. These systems may have aging infrastructure, inadequate treatment, or management challenges.

How is reliability different from safety score?

The reliability score focuses specifically on the water utility performance (violations, resolution, compliance). The Home Safety Score is broader, also including lead risk, radon, and flood data. A ZIP code can have a reliable water system but still have high radon or flood risk.