Dear Mr. Gramlich,
Since January, 2021, Division 2 has taken the lead in the Department of Water Resources’ (DWR) Pond Enforcement initiative. However, there are facts the DWR is not revealing when telling property owners they must fill in or augment their ponds. Either choice could cost property owners tens of thousands of dollars. I believe pond owners should have all the pertinent information before making a decision involving that kind of money. Following are only a few of the factors that should be considered.
WHAT IS PAN EVAPORATION?
According to Colorado University-Boulder, the outdated method of pan evaporation is what the Colorado DWR uses to measure evaporation from ponds. Developed in the 1920s, pan evaporation is determined by taking a 4-foot-in-diameter, 10-inch-deep pan filled with water, and setting it next to a selected reservoir. Evaporation is measured every twenty-four hours, and the results are used to calculate evaporation on corresponding reservoirs. This may have changed, but in 2020, while working for the DWR, I was told evaporation research for Division 2 is done at the Pueblo Reservoir. The problem is no two reservoirs are the same, let alone the Pueblo Reservoir and any pond in the headwaters of the Arkansas River Basin (Division 2). Size, shape, elevation, location, wind speed, air and reservoir temperatures at the surface, humidity, solar radiation and vegetation around the reservoir, all play a part in determining evaporation. I have proof from a 1990s water court case in Division 2, where an owner augmented his two ponds and the actual evaporation from those ponds is less than half of what was calculated in the water court case. One reason for this could be that most of the ponds in the headwaters area of Division 2 are fed by cold water springs, which are colder than the Arkansas River. Less evaporation in the ponds and creeks of the headwaters than the river itself.
WHAT IS A RECHARGE POND?
By definition, recharge ponds are engineered ponds that are used to prevent flooding and downstream erosion and are designed to let water seep into groundwater aquifers. In mountainous regions recharge ponds are also used to catch surface runoff and increase infiltration to recharge groundwater and aid in natural spring recharge. I asked Rachel Zancanella, Division 2 Engineer, on May 11, 2023, in front of a group of people in Westcliffe,
if draining some of the area ponds wouldn’t cause the level of the aquifers to decrease, and in turn cause area wells to dry up. I was told no, however I still think yes!
DWR DATA – POND CRACKDOWN
The Colorado Department of Water Resources was recently asked for data on the amount of water that has been added back to the total system for the Kansas Compact and downstream senior priorities, because of their pond crackdown. The DWR is not giving up data for anyone to see, and not talking about why.
IN CONCLUSION – MY OPINION
I think that because of these reasons plus several others I have researched, the DWR should cease and desist any activity having to do with their Pond Enforcement initiative. At least until the DWR provides confirmed data that their pond crackdown is actually adding to the total amount of water in the system for the Kansas Compact and downstream senior priorities.
Thank you,

Laurie Assemany,
Coaldale, Colorado