City of Wichita, Kansas
2016
It is nearly impossible to overstate the value of good quality data when it comes to enabling a city to manage its water supply and develop conservation strategies. That reality is the reason the city of Wichita, Kansas., turned to Water Resources Solutions in 2016 to map and characterize its irrigation water use in relation to the city’s municipal supply. WRS coupled water-use characterization with planning-level assessments of groundwater, surface water and consumption, discovering an important but under-appreciated vulnerability in Wichita’s ability to meet demand: an over-reliance on thousands of private water wells drawing from the underlying groundwater aquifer with little to no regulation. Conservation, policy, public-education and structural recommendations were made.
The study included a review of the existing city ordinances related to water conservation and recommendations were made regarding strengths and weaknesses of the ordinances. A water use audit was completed to identify the current irrigation water use within the city. This analysis was completed through the use of city records and a GIS model. The city’s water data was related to the land parcels in the city using GIS. This allowed an evaluation of water use by land ownership and land use type.
A consumptive water use evaluation was completed to determine the actual irrigation water requirements for the city. The consumptive water use was calculated using the Penman-Monteith equation and climate data from a weather station in Sedgwick County operated by Kansas State University. A surface water evaluation was completed to identify potential surface water storage areas within the city. This evaluation was completed using GIS to identify potential sites based on proximity to stream, land ownership, and quantity of open area.
A groundwater investigation was completed to evaluate the available water supply from the groundwater aquifers available to the city and to determine future irrigation capacity that could be supported by the groundwater supply. The groundwater analysis included the evaluation of the supplies for three different groundwater aquifers that included the Equus Beds (part of the Ogalalla aquifer), a shallower alluvial aquifer along the Arkansas River, and a bedock aquifer (Wellington formation).
A water conservation toolbox was developed that identified technology tools; landscape alternatives; best management practices; policies, ordinances, and regulations; and public education and outreach opportunities. Finally, the GIS model was used to model three water conservation scenarios using different combinations of groundwater, surface, and existing municipal finished water supplies. The purpose of the scenarios was to evaluate the reallocation of the three water sources.