PUB00084

• Year: 2004
• Title: Artificial Recharge of Ground Water in Colorado -- A Statewide Assessment
• CWCB Section: Administration
• Author: Colorado Geological Survey
• Description: This study was a special assignment to the CGS from the DNR Executive Director. The tqask was to assess the underground water storage options potentially available in our state.
• Publications - Doc Type: Tech Report

I
I
I

Anificial Rechar~e of Ground Water in Colorado
A Slate-wide A!lst"s!lmcnl

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

Surfal'e Infillration
Surface infiltration is simply the impoundment of water at the ground surface for the purpose of
to soaking into the underlying ncar-surface. unconfined aquifer. Surface-infiltration recharge
systems arc suitable for unconfined aquifers where \\...alcr levels arc relatively shallow and
impermeable layers are absent between the ground surface and the base of the aqui fer.
Receiving aquifers typically have relatively high transmissivities to accommodate latcralllow
away from the recharge area and thus prevent the [annal ion of high ground-water mounds.

Varying in shape from symmetrical ponds to long linear ditches. and in size from several acres to
several hundred acres, surface infiltration design is highly dependant on surface conditions.
Structures can be entirely constructed on flat land or can take advantage of natural topography.
Surface infiltration systems may cover large areas, but can be relatively simple to construct. The
structures can coexist with other uses such as recreation and wildlife habitat, but compatibility
with adjoining land use is an important consideration. As in surface-water reservoirs.
evaporative losses must be considered.

The general types of surface infiltration structures, illustrated in Fieure IV-I. arc described
below:

. Infiltration ponds and spreading hasins - Circular or rectilinear structures into which
\vatcr is directed and allowed to infiltrate through the bottom. These may be constructed
above grade or excavated below grade and often take advantage of existing excavations
such as gravel pits or water storage reservoirs that naturally leak. Temlinology typically
refers to small structures as infiltration ponds or basins and larger scale structures as
spreading hasins.

. Infiltration ditches -Water is directed into linear structures and allowed to infiltrate
through the bottom. Often. these take advantage of existing \vater conveyance ditches
and canals that naturally leak. They can be adapted to topographic conditions that
prohibit large inliltration ponds and basins.

. Stream challllels - Water is directed to natural ephemeral or perennial streams. Dry
stream channels may require little modification in sitmltions \\'here the channel
morphology and highly pemleable streambed material allow for rapid infiltration. This
method may also involve construction of dams or low weirs across the channel to back
the water up and increase the wettcd surface area of the streambed or floodplain.
providing a larger area for infiltration into the ground.

. Playa lakes ~ These ephemeral lakes are natural topographic depressions where water is
directed for recharge. Surface modification may be required to increase lakebed
penneability.

. Land application - This involves over. irrigation of fields at rates where excess soil
moisture infiltrates down to the underlying aquifer.

16