WSP00209

• File Number: 8460.500
• Description: Platte River Recovery Plan
• Basin: South Platte
• Date: 5/30/2000
• Author: CWCB
• Title: Draft Water Action Plan
• Water Supply Pro - Doc Type: Publication

for recharge basins or pipe drains. The construction cost associated with recharge basins
or pipe drains will vary based on the size and location of the basin or length of the drain.
There will also be annual operations and maintenance costs. The cost of the recharge
collection/distribution system and annual operations and maintenance costs were based
on data provided by the EIS team. The total cost of the wells and recharge system and
annual operations and maintenance costs were estimated to be about $346,000 and
$12,600, respectively.

o Third-Party Impact Considerations:

A groundwater management program can alter the timing and quantity of water in the
river, in which case, there are potential hydrologic and corresponding economic third
party impacts on downstream users. Third party impacts associated with dry-land
farming are similar to land fallowing as discussed under water management programs.
Third party impacts associated with the remaining groundwater management programs
are discussed below.

In general, groundwater programs result in positive hydrologic impacts. Actively
pumping from high groundwater areas, conversion to groundwater irrigation, and
conjunctive use projects all typically increase flows in the river. Additional flows under
this scenario may allow downstream junior water rights holders to make greater use of
their water rights. A conjunctive use project would reduce available flows for junior
downstream water users during the winter months when water would typically be
di verted for recharge.

Pumping from high groundwater areas may lower regional groundwater levels, which
could have both positive and negative impacts. Negative impacts include increased
pumping costs for nearby groundwater irrigators due to lower groundwater levels.
Alternatively, lower groundwater levels would decrease waterlogging of nearby irrigated
lands and alleviate problems with flooded basements, both of which are positive impacts.
Conjunctive use projects will lower and raise groundwater levels at different times of the
year, which could have both positive and negative impacts. There could be negative third
party impacts on landowners adjacent to creeks or drains used to return groundwater to
the Platte River if waterlogging problems are increased.

In general, these projects will have minimal direct or indirect impacts on business sales,
employment, wages, and wealth. Any third party economic impacts will likely be related
to impacts on agricultural production in the affected area. For example, lowering
groundwater levels could decrease waterlogging problems and increase agricultural
productivity. Diversions to recharge through existing canals will reduce the opportunity
for the owner to use that conveyance capacity, however, it may increase revenues from
deli very fees.

There could be numerous environmental impacts associated with groundwater
management projects. Similar to the Tamarack Recharge Plan, conjunctive use projects
can generate wetlands and wildlife habitat if recharge basins are incorporated. Impacts on
water quality can be both positive and negative. Recharge projects could improve water
quality on-site due to the creation of wetlands. Water quality could also improve during
the summer months when additional flows resulting from these projects return to the

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