Boulder Creek drops to summer low amid nitrogen spike

July 11, 2026

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Boulder Creek has dropped to summer low — barely 0.43 cubic feet per second this week — and the timing could not be worse. At flows this shallow, the stream loses its capacity to dilute nitrogen discharges, and right now that matters acutely: the wastewater treatment plant upstream exceeded its nitrogen limit by 45% last week.

The creek sits on Colorado's impaired-waters list, which means every exceedance matters more. In July, when water is scarcest and permit assumptions break down, is exactly when the gap between what regulations allow and what the stream can actually absorb becomes visible. This is the narrow window when permit numbers and real ecological harm draw closest.

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