How Deep Is Cherry Creek Reservoir

Cherry Creek Reservoir, a significant water storagefacility nestled within the bustling Denver metropolitan area, serves as a critical component of Colorado's water management infrastructure. Its substantial size and strategic location make it a focal point for both practical water supply needs and recreational activities. Understanding the depth of Cherry Creek Reservoir is not merely an academic exercise; it directly impacts its capacity to store water, its ecological balance, and the safety protocols governing activities on its surface. This article delves into the precise measurements, the science behind its depth, and the broader implications of this vital statistic.

Maximum Depth: The Deep End of the Reservoir

The most commonly cited figure for the maximum depth of Cherry Creek Reservoir is approximately 150 feet (46 meters). This measurement refers to the deepest point within the reservoir's main basin, typically located near the dam structure. This significant depth is a direct result of the reservoir's design and the specific geological characteristics of the Cherry Creek valley where it was constructed. The dam, standing about 190 feet high, creates a substantial impoundment capable of holding a massive volume of water. The depth is crucial because it determines the reservoir's storage capacity and influences water flow dynamics downstream.

Average Depth: A More Representative Measure

While the maximum depth is impressive, the reservoir's overall efficiency and behavior are more accurately reflected by its average depth. Estimates suggest the average depth of Cherry Creek Reservoir ranges from 15 to 25 feet (4.5 to 7.6 meters). This figure is significantly lower than the maximum depth, highlighting the vast area covered by the reservoir. The shallow average depth is characteristic of many large, man-made reservoirs, especially those designed primarily for flood control, water supply, or recreation rather than deep-water storage. The shallow profile allows for faster warming of the water in summer months, which has implications for water quality and aquatic life.

The Science Behind the Depth

The depth of Cherry Creek Reservoir is not arbitrary; it's the result of careful engineering and environmental considerations:

1. Design Purpose: The primary function of Cherry Creek Reservoir dictates its depth profile. Constructed in the 1980s, it was designed to manage flood control for Cherry Creek downstream, provide a reliable municipal water supply for the City of Aurora and surrounding areas, and offer recreational opportunities. A deep reservoir is less efficient for flood control, as it takes more time to fill and drain. A shallower reservoir is better suited for rapid floodwater storage and release. The chosen design balances these competing needs.
2. Geological Constraints: The natural topography of the Cherry Creek valley sets the upper limit on how deep the reservoir can be excavated. The surrounding hillsides and the creek's own channel depth influence the maximum possible depth.
3. Dam Height and Storage Volume: The height of the dam (about 190 feet) directly relates to the potential maximum depth behind it. However, the reservoir's total storage capacity (around 150,000 acre-feet when full) is also a critical factor. The combination of dam height and the reservoir's surface area determines the depth. A larger surface area means a given volume of water results in a shallower depth.
4. Sediment Accumulation: Over decades, sediment from the watershed washes into the reservoir. This sediment gradually fills the deeper parts near the dam, effectively reducing the maximum depth over time. Regular dredging is often necessary to maintain capacity and depth.

Implications of Depth

The depth profile of Cherry Creek Reservoir has several practical consequences:

• Water Supply Reliability: The reservoir's ability to store water for Aurora and surrounding areas depends heavily on its total volume and surface area. The shallow average depth means a larger surface area is required to store the same volume of water compared to a deeper reservoir. This has implications for evaporation rates – a larger surface area exposed to the sun leads to greater water loss through evaporation, especially in the hot Denver summers. This is a significant factor in the reservoir's operational efficiency for water supply.
• Flood Control Effectiveness: The reservoir's design prioritizes flood control. Its relatively shallow basin allows it to fill and release water more quickly than a deep reservoir, reducing the risk of downstream flooding during heavy rains or snowmelt.
• Recreation and Safety: The reservoir is a popular recreation spot for boating, fishing, and hiking. The shallow average depth makes it generally safer for swimming and boating activities compared to a deep reservoir. However, boaters must be aware of the varying depths and potential submerged hazards. The depth profile also influences water temperature, which affects fish populations and swimming comfort.
• Water Quality: Shallow reservoirs warm up faster in summer, which can lead to issues like algal blooms if nutrient levels are high. The depth profile also affects oxygen levels, particularly in the deeper areas near the dam, which can impact aquatic life.

Frequently Asked Questions (FAQ)

• Q: Is Cherry Creek Reservoir deeper than other Denver metro reservoirs? A: Compared to some of the larger, deeper reservoirs in the Denver Water system like Dillon Reservoir (max depth ~250 ft) or Standley Lake (max depth ~70 ft), Cherry Creek Reservoir's maximum depth of ~150 ft is moderate. Its average depth is shallower than Standley Lake but deeper than many smaller local reservoirs.
• Q: Can I swim in Cherry Creek Reservoir? A: Swimming is generally allowed at designated beaches within the reservoir's recreation area. However, it's crucial to check current conditions, posted rules, and safety advisories from the managing agency (usually Denver Water or the City of Aurora). Always swim with a buddy and be aware of the water depth and potential hazards.
• Q: Why isn't Cherry Creek Reservoir deeper? A: The depth is primarily constrained by the natural topography of the Cherry Creek valley and the dam height. Its design prioritizes flood control and a large surface area for water supply and recreation over maximum depth. Sediment accumulation over time also reduces effective depth.
• Q: How does the depth affect the fish population? A: The shallow average depth and warmer summer temperatures can limit the types of fish that thrive. Common species include largemouth bass, bluegill, crappie, and channel catfish. Deep-water species are less common. The depth profile influences spawning habitats and oxygen levels.

Conclusion

The depth of Cherry Creek Reservoir, approximately 150 feet at its deepest point and averaging 15-25 feet, is a fundamental characteristic shaping its function and use. This depth, dictated by engineering design, geological constraints, and the need for effective flood control and water supply, results in a reservoir with a large surface area relative to its volume. This shallow profile impacts evaporation rates, water temperature, recreational safety, and the types of aquatic life it supports. Understanding this depth is key to appreciating how Cherry Creek Reservoir efficiently balances its critical roles in managing water resources and providing recreation within the dynamic environment of the Denver metropolitan area. Its depth is not just a number; it's a defining feature of this vital water resource.