Reservoirs and Ponds

This summer has been difficult for the water features in TrailMark. The heat and lack of rain resulted in more stagnant water with algae blooms and smells. The District hires aquatics professionals to monitor and treat the water but only so much can be done when Mother Nature doesn’t help. The TMMD thanks those who have called to report conditions.
For your reference the map shows the open space areas in TrailMark the entity responsible for maintenance.

Many questions have been received about why the water level in Pond G has been lower than usual.

Pond G (in the open space near the Two Brands Trail in the Hilderbrand Ranch Open Space) was designed to be a detention pond that collects stormwater and slowly releases it downstream (in this case, to the Botanic Gardens). Over the past few years, the water has been elevated over its designed level due to the outlet structure being blocked with silt. The City of Littleton Water Resource Manager inspected Pond G in 2019 and required the TMMD to clean the outlet so the water flowed as was designed. While the pond level is much lower than in the past few years, it is now operating as designed. With the water level lower after being high for a few years, there is a smell to the drying out process. It has improved in the past few weeks with the heat. The District has an ongoing aquatic maintenance company and they will work to reduce algae and odor while trying to keep good water quality. While Fairview Reservoir #1 is stocked for fishing, the only fish that are stocked in pond G are grass carp designed to help with vegetation control.
Compliance with federal, state and local stormwater is a complicated issue that has become more regulated in recent years. It is inevitable that the silt will fill the outlet again, and therefore will be cleaned routinely in order to comply with stormwater regulations (the outlet was last cleaned in 2013).
Below is the contact information for those who would like to learn more about the requirements of the city and the approved TrailMark stormwater system design:
Carolyn Roan, PE, CFM
Water Resource Manager
Public Works
2255 West Berry Avenue
Littleton, Colorado 80120
720-982-9235 (mobile)
303-795-3865 (front desk)
Fairview Reservoir #2 (Beaver Pond)
This water feature near Star Canyon is also part of the overall drainage system and is suffering from the heat and lack of fresh water. The pond has a solar aeration system to help water movement, and repairs have been ongoing this summer. It is not a fishing feature and if anyone sees dead fish, they were not meant to ever be in the pond and may be the result of the fish moving thru the water drainage system. The odor can be the result of an algae die off due to treatment or water not moving enough.
Fairview Reservoir #1
The largest water feature in TrailMark, Fairview #1 is meant to hold water and be a fishing and visual amenity. However, water is released according to water law requirements so the water level can fluctuate. The water in Fairview #1 was spot treated for surface algae mats in May and has been treated on a weekly basis since late June for a problematic phytoplankton bloom with major treatments performed regularly. While some improvement in water clarity was evident, a third phytoplankton treatment will likely be needed this month to curb the ongoing bloom and stabilize water quality conditions. There is also aeration in Fairview to help with water quality and the system has been working correctly.
We all enjoy having water and wildlife nearby and try to preserve it when possible. However, it is a balancing act with regulations and Mother Nature’s input. 
Mosquito Treatment 

As for mosquitos, the District hires Vector Disease Control International to test and treat mosquito activity at all our water sites. This company also does the Botanic Gardens (including fogging) and have had reports of high mosquito activity in the area. The District has asked for the areas to be checked again, but depending on when it rains, the heat and the timing of their visits to TrailMark, mosquito activity can vary. The testing also looks for West Nile or other insect borne diseases.

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