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Colorado Water Law and How to Garden Anyway   arrow

Colorado Water Law and How to Garden Anyway

Irene Shonle
Colorado State University
CSU Extension in Gilpin County

  • For many wells, no outside watering is permitted.
  • Even if watering is permitted, there may not be enough ground water.
  • Colorado has an arid climate, and even native and xeric plants need water to get established.
  • The diversion and use of rainwater is subject to Colorado water law, making it difficult to harvest.

Water law

Many newcomers to the mountains are shocked to realize that they are not permitted to water outside their houses. This puts a serious crimp into their gardening plans. Before we go into how to grow a garden within the confines of the water law, let’s examine the laws more closely.

The use of water in this state and other western states is governed by what is known as the prior appropriation doctrine. This system of water allocation controls who uses how much water, the types of uses allowed, and when those waters can be used. A simplified way to explain this system is often referred to as the priority system or “first in time, first in right.”

An appropriation is made when an individual physically takes water from a stream or well (when legally available) and puts that water to beneficial use. The first person to have appropriated water and applied that water to use has the first right to that water within a particular stream system. This person, after receiving a court decree verifying their priority status, then becomes the senior water right holder and that water right must be satisfied before any other water rights are filled. In Colorado, the State Engineer has the statutory obligation to protect all vested water rights. The process of allocating water to various water users is traditionally referred to as water rights administration, and is the responsibility of the Division of Water Resources.

Most of the stream systems have been over-appropriated, meaning that at some or all times of the year, a call for water even by a senior appropriator is not satisfied. Practically speaking, this means that in most river drainages, a person cannot harvest rainwater without a plan for augmentation that replaces the stream depletions associated with that diversion.

State Well Regulations

The Colorado Division of Water Resources regulates the drilling and use of wells (underground water). In the past, the lack of strict regulations caused a significant drop in the water table in some communities, creating problems for well users. Currently, new well permits are very restrictive. Most wells are used for households and are considered “exempt” from the administration within the water rights priority system. They require a permit from the State Engineer, and are limited to 15 gallons of water per minute.

Most private wells drilled on or after May 8, 1972 on properties less than 35 acres are permitted for household-use only. Water can be used only inside the home. Water cannot be used to irrigate gardens, windbreaks, livestock, or any other outside use. The theory behind this is that household use only “uses” 10% of the water, and the rest returns to recharge the water cycle.

For more information:

Where does our water come from?

Unlike wells in other places, mountain wells tap into “fractured rock aquifers.” These are spaces or fractures between subterranean rocks that are saturated with water. These cracks can be as small as a human hair. To provide reliable water, a well must intersect many well-connected water-bearing fractures. The amount of water a well produces depends on how much water the fracture system bears. (Interesting fact: a five gallon bucket filled with sand and gravel could hold 16 cups of water. The same amount of fractured rocks could only hold 3 teaspoons of water!) Excessive use of water can draw down the water in the aquifers, and cause wells – either yours or a neighbor’s – to go dry. We depend on precipitation to recharge our groundwater and reservoirs, but this isn’t always reliable. In fact, some part of Colorado is almost always in drought! So, it is better to treat this precious resource with respect and caution.

Rainwater Harvesting

As of August, 2016, it is now legal to collect up to 110 gallons of rainwater from the roof of residential houses!  This is enough to maintain a small vegetable garden, a larger ornamental garden, and/or to water hanging baskets and pots. For more information:

Another legal way to use rainwater is to direct roof gutter downspouts to drain to landscape areas you wish to water.

There are ways to garden anyway.

You may have to adjust your aspirations. Instead of growing large vegetable gardens (which  can take a tremendous amount of water), or flower beds full of thirsty plants, you many need to focus on wildflowers and other native/xeric plants.

Plan your garden carefully – add lots of organic matter to the areas where you want to try to grow plants which prefer a little more water (organic matter acts like a sponge to help hold in the water), and direct your downspouts to water this area. Roll-out downspouts, diffuser heads and soaker hoses (with no ends on them to hold in the water) can direct water to more moisture-loving plants.

Another option is to “Plant with the precipitation.” We often get a monsoon rainy season starting sometime in July. Native and xeric plants (bought in pots) that are planted during this time will usually successfully establish with only the natural rainfall (and one good watering-in on the day that they are planted). Please see our high and dry websites for more information: Gilpin County Extension High and Dry Gardens

A final option is to sow wildflower seeds and grasses in the fall. You can create a beautiful, low water meadow full of color, butterflies, and birds this way. Sowing seeds in the fall is ideal because this is when they are naturally sown by the plants. The cool wet of the winter stratifies the seeds, and allows them to break dormancy in the spring. The snow will help to keep them watered, and will keep the birds off of them. For more detailed information on how to sow wildflowers, see

Webinar: No-water Gardening for Higher Elevations (above 7500’)

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