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	80477	Steamboat Springs	CO	25/100	72/100
11	80487	Steamboat Springs	CO	25/100	67/100
12	80488	Steamboat Springs	CO	25/100	69/100
13	80540	Lyons	CO	25/100	35/100
14	81044	Hasty	CO	25/100	37/100
15	81047	Holly	CO	25/100	33/100
16	81067	Rocky Ford	CO	25/100	45/100
17	81069	Rye	CO	25/100	40/100
18	81084	Two Buttes	CO	25/100	47/100
19	81089	Walsenburg	CO	25/100	44/100
20	81090	Walsh	CO	25/100	34/100
21	81419	Hotchkiss	CO	25/100	57/100
22	81435	Telluride	CO	25/100	59/100
23	81321	Cortez	CO	27/100	66/100
24	81615	Snowmass Village	CO	27/100	66/100
25	80133	Palmer Lake	CO	28/100	66/100
26	81144	Monte Vista	CO	28/100	73/100
27	80465	Morrison	CO	30/100	56/100
28	80747	Peetz	CO	30/100	51/100
29	80758	Wray	CO	30/100	58/100
30	81049	Kim	CO	30/100	58/100
31	81055	La Veta	CO	30/100	53/100
32	80421	Bailey	CO	32/100	69/100
33	80818	Genoa	CO	32/100	46/100
34	80861	Vona	CO	32/100	61/100
35	81045	Haswell	CO	32/100	61/100
36	81654	Snowmass	CO	32/100	56/100
37	80136	Strasburg	CO	33/100	63/100
38	81430	Placerville	CO	34/100	65/100
39	81649	Red Cliff	CO	34/100	71/100
40	80437	Evergreen	CO	35/100	52/100
41	80439	Evergreen	CO	35/100	42/100
42	80454	Indian Hills	CO	35/100	62/100
43	80511	Estes Park	CO	35/100	59/100
44	80517	Estes Park	CO	35/100	54/100
45	80536	Livermore	CO	35/100	34/100
46	81064	Pritchett	CO	35/100	49/100
47	81324	Dove Creek	CO	35/100	47/100
48	80728	Fleming	CO	37/100	65/100
49	80744	Ovid	CO	37/100	61/100
50	80118	Larkspur	CO	38/100	60/100
51	81432	Ridgway	CO	38/100	41/100
52	80467	Oak Creek	CO	40/100	68/100
53	80537	Loveland	CO	40/100	49/100
54	80538	Loveland	CO	40/100	54/100
55	80539	Loveland	CO	40/100	59/100
56	80545	Red Feather Lakes	CO	40/100	61/100
57	80860	Victor	CO	40/100	56/100
58	80863	Woodland Park	CO	40/100	59/100
59	80866	Woodland Park	CO	40/100	52/100
60	81019	Colorado City	CO	40/100	57/100
61	81328	Mancos	CO	40/100	56/100
62	81424	Nucla	CO	40/100	60/100
63	81429	Paradox	CO	40/100	49/100
64	81434	Somerset	CO	41/100	67/100
65	80135	Sedalia	CO	42/100	64/100
66	81124	Capulin	CO	42/100	82/100
67	81623	Carbondale	CO	44/100	68/100
68	81252	Westcliffe	CO	45/100	55/100
69	81326	Hesperus	CO	45/100	46/100
70	81423	Norwood	CO	45/100	55/100
71	81643	Mesa	CO	45/100	64/100
72	80476	Silver Plume	CO	46/100	67/100
73	80483	Yampa	CO	46/100	79/100
74	81071	Sheridan Lake	CO	46/100	62/100
75	80459	Kremmling	CO	47/100	65/100
76	80727	Eckley	CO	47/100	61/100
77	80737	Julesburg	CO	47/100	61/100
78	80832	Ramah	CO	47/100	69/100
79	81054	Las Animas	CO	47/100	61/100
80	80621	Fort Lupton	CO	48/100	61/100
81	80654	Wiggins	CO	48/100	57/100
82	80101	Agate	CO	49/100	64/100
83	80301	Boulder	CO	49/100	58/100
84	80302	Boulder	CO	49/100	53/100
85	80303	Boulder	CO	49/100	53/100
86	80304	Boulder	CO	49/100	53/100
87	80305	Boulder	CO	49/100	58/100
88	80306	Boulder	CO	49/100	68/100
89	80307	Boulder	CO	49/100	64/100
90	80308	Boulder	CO	49/100	68/100
91	80309	Boulder	CO	49/100	64/100
92	80310	Boulder	CO	49/100	64/100
93	80314	Boulder	CO	49/100	64/100
94	80321	Boulder	CO	49/100	64/100
95	80322	Boulder	CO	49/100	64/100
96	80323	Boulder	CO	49/100	64/100
97	80328	Boulder	CO	49/100	64/100
98	80329	Boulder	CO	49/100	64/100
99	80549	Wellington	CO	49/100	63/100
100	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.