O&M Activities

There has been a lot of interest in what it takes to operate and maintain the Tarryall Ranch Reservoir (“the Reservoir”) and its structures along with the augmentation plan and associated water rights. We think it is great that everyone would like to know more so we created this page to inform you on the recent and upcoming activities at the reservoir.

As you will read, it takes a significant amount of resources to properly operate and maintain an augmentation system. Having uninterrupted use of your well is important to every homeowner. We want our customers to feel secure knowing they have reliable augmentation service for years to come. That is why we want to share with you the hard work involved with maintaining your augmentation service.

These operations and maintenance activities are funded by your augmentation fees. We have spent a significant amount of money so far and expect to spend a great deal more with the necessary work we have planned. We hope you find this information useful and look forward to updating you on the latest activities.

2022-2024 Activities

We continue to improve the water transportation structures to allow for more efficient flow through Longs Pond and Slater Ditch. There is also quite a bit of work to do this on the damn itself to remediate animal burrows and invasive vegetation. We continue to improve erosion controls and monitor the levels of the lake.

2021 Activities

The new flow meter is being installed in the Slater Ditch as required by the State. The project should be completed shortly. We are also working on removing debris in Longs Pond and maintenance of the Slater Ditch so water can be diverted.

2020 Activities

Maintenance items such as repair to rodent holes, Slater Ditch improvements and head gate maintenance were conducted throughout the year.

In October, Bar Star hired Guildner Pipeline Maintenance to video the inside of the outfall pipe in order to assess its condition. According to report, no issues were detected and the pipe appears to be intact. It is still the engineer’s recommendation to replace the outfall pipe as it has reached its useful life.

The State has required a new flow meter to be installed in the Slater Ditch before water can be diverted. The meter has already been purchased by Bar Star, but we are awaiting the contractural payment from Elkhorn to complete the project. Thanks to hard work by Bar Star over the last several years, there was sufficient water in storage to be able to make the required releases for residences of Elkhorn and Indian Mountain. Bar Star is working with Elkhorn to come current on its payments so water diverted during the 2021 water season.

2019 Activities

As discussed in our plans for our 2018 Activities, Bar Star hired a specialized dam engineering firm, W.W. Wheeler and Associates Inc.,  to conduct an assessment of the Reservoir and provide a feasibility cost opinion to perform specific dam repair work. The report of their findings was completed in September 2019. This report will help Bar Star and Elkhorn plan and budget for future repair and maintenance items.

Throughout the year Bar Star was busy making repairs to the water diversion structures and dam maintenance.

2018 Activities

As usual, during the months of March, April and May Bar Star was been busy making repairs to the water diversion structures to allow the Reservoir to be filled more efficiently.

In July we finished our fencing project and are very excited to report that the Reservoir and Dam are now completely fenced so livestock will not have access.

In August we plan to have an assessment done of the Reservoir and its support structures by a third party engineering firm. We anticipate the assessment will find some of the structures have reached their useful life and will need to be replaced or repaired.

Ongoing monthly activities include coordinating with the Division of Water Resources to ensure that water is diverted according to law, accounting for water diverted to and from storage, and monitoring matters that may impact the water rights in water court.

2017 Activities

During the months of March, April, May and June, BSWC was been busy making repairs to the water diversion structures, which include the Slater Ditch and Longs Pond.

We also have been actively diverting water for the augmentation season as our water rights come into priority. Our quarterly dam inspections have continued to occur on schedule. During the inspections areas with rodent holes were properly addressed and plans were discussed to add more riprap in areas.

We plan to camera inside of the outfall pipe on the dam this year to understand its condition. The outfall pipe, which was installed in the 70’s, is made from corrugated metal and is reaching its expected life.

Please stay tuned as we update you on more of BSWC’s operations and maintenance activities through the year.

2016 Activities

Headgate and Culvert Installation – During the week of October 17th substantial repairs were made to the Slater Ditch complex.  The Slater Ditch headgate had reached its useful life and was no longer operational, so much so that the Water Commissioner required BSWC to replace this headgate before any diversions to the Reservoir could take place.  Using heavy equipment, a local contractor removed the nonoperational headgate and replaced it with a new headgate and culvert to Slater Ditch.

The Slater Ditch diversion structure on Tarryall Creek was also in desperate need of repair.  Historically, rocks and other debris were used to divert water into the Slater Ditch.  This was a very time and labor intensive process.  Using the same heavy equipment, a more substantial diversion structure has been installed that will hopefully result in more efficient operation of the Slater Ditch complex.

The Water Commissioner required these repairs prior to allowing water to be diverted into storage. We are very happy to have this project completed and are now able to run water to the lake for storage for the next augmentation release.

Slater Ditch Flume Repaired – the flume that measures the cubic feet per second flow of the Slater Ditch when we are diverting water had sunken over time and was not level.  The flume needs to be level in order to correctly measure the flow. The Water Commissioner required that this repair be made prior to diverting water.  We were able to successfully re-level the flume and it is now functioning properly.

Bathymetric Survey – A bathymetric survey is the study of the depth of a body of water relative to its surface level.  In the same way that topographic maps represent the three-dimensional features of overland terrain, bathymetric maps illustrate the land that lies underwater.

The bathymetry of a reservoir will change over time from the accumulation of silt and organic matter and the action of wind and waves.  Changes in bathymetry affect the volume of water the reservoir can hold which is of special concern to the water district who administers water rights and has to account for the volume of water diverted by each water right holder. Therefore, the Water Commissioner required that we perform a bathymetric survey before we could divert water.

We hired a geological consulting company to perform the bathymetric survey which took approximately one month to complete.  The results were provided to the Water Commissioner.

Capacity Curve -The Water Commissioner also requested a capacity curve be developed to determine the surface area of the reservoir water at different elevations.  We were able to use the data gathered from the bathymetric survey along with survey and GPS data points gathered during study to formulate a curve.

October Augmentation Release – The water commissioner requires augmentation releases periodically from the Reservoir for the Indian Mountain Subdivision to cover the  non-irrigation season depletions.  What you may not know is how technical an augmentation release actually is.  Because the Reservoir’s staff gauge is very rudimentary, we have to take special precautions to release the correct amount of water. Custom instrumentation and measuring instruments are used to measure the release. It took a full day to set up the instrumentation and conduct the release.

October Water Diversion to Storage – Once the bathymetric survey and the head gates were installed, we were allowed to divert water to storage for the first time this year.  When water is diverted, we have to continuously monitor the structures.  The flume level is closely monitored to make sure we stay within our allowable flow rate. The Slater Ditch (approximately 7 miles) is inspected around the clock to make sure water is flowing efficiently to limit ditch loss. Typically, we must make several repairs to the ditch during this time. Daily communication with the project geologist is also required to monitor the volume of water being stored.

5 year Dam Safety Inspection – Every five years the Division of Water Resources Dam Safety Engineer conducts a safety inspection of the dam and its structures in accordance with Section 37-87-107 C.R.S. This report details the conditions observed during the inspection and identifies actions required to improve the conditions and extend the useful life of the structure. He/she also determines the safe storage level of the dam at its observed condition.  Which may be anywhere from zero to full capacity depending on the condition of the structures.

The Reservoir is able to store at its full capacity, but the State Engineer noted several repairs that will be required. The repairs are typical given the age of the Reservoir.  The State Engineer acknowledged Bar Star Water’s diligent maintenance program which has served to extended the life of the dam.

Continuous Operation and Maintenance

Monthly Resume Review – Each month our general counsel reviews the Division 1 Water Court Resume to determine if any statements of opposition need to be filed in any of the cases described.  We do this to protect the augmentation plans and associated water rights.

Legal Work – If any water rights applications in the Division 1 Water Court Resume appear to have the potential to adversely impact the Indian Mountain augmentation plan water rights, we will file what is known as a statement of opposition and participate in individual cases in water court.

Finally, since we purchased the Reservoir and augmentation plan from IMC in 2013, we have had to defend the Reservoir and water rights in Park County District Court and the Colorado Court of Appeals from both the Indian Mountain Metropolitan District and the Elkhorn Ranch Homeowners Association.  This litigation has cost the company hundreds of thousands of dollars.

Quarterly Dam Inspections – Every quarter an engineer visits the dam to conduct a Dam Inspection in accordance with the Colorado State Engineers Office’s Dam Safety Manual January 2002 (the “Manual”).  A thorough visual inspection is performed of the structures in accordance with the Manual’s requirements. The inspector also notes any repairs that are necessary.

Quarterly Repairs –  Any repairs noted during the Quarterly Dam Inspection are completed by Bar Star Water in a timely fashion. These repairs typically include rodent hole repairs, replacement of aggregate, revegetation, vegetation control, and erosion repair.

Ditch Maintenance – this is a laborious and ongoing chore with 7 miles a ditch to maintain.  The Slater Ditch is an earthen ditch that extends for almost 7 miles from the lake across highway 285 and connects with Tarryall Creek.  Due to erosion cause by wind, water, wildlife, and humans, we are constantly maintaining the structure to make sure water can flow.  It is terribly inefficient.  We spend several hours a year repairing the ditch with the use of heavy equipment and manpower.  We are excited about the possibilities of making the ditch more efficient and have been consulting with engineering specialists on how to make this happen.

Augmentation Releases – Occurs as directed by the Water Commissioner.

Future Projects

  • Installation of new staff gauge
  • Installation of new outfall pipe
  • Repair eroded areas of the spillway channel
  • Add aggregate to balding areas
  • Repair wave eroded areas
  • Clean spillway
  • Raise spillway to originally designed elevation
  • Line Slater Ditch to prevent ditch loss


The old head gate once it was removed.


Water flowing through new Slater Ditch headgate.


The new culvert diverting water into Slater Ditch.


Improved Slater Ditch/Tarryall Creek diversion structure.


The repaired flume inside the Slater Ditch during a diversion.


Markers where animal burrows need repair during a quarterly inspection.