This morning the consultant performing the In-stream Flow Incremental Mthodology (IFIM) study needed for our application for a permanent modification of our Virginia Water Protection Permit, and the associated down stream release schedule, began the second and, weather permitting, third flow stages to collect data at the ten (10) transect locations. The river flow target for the second stage is 150 cfs (97 mgd) and the flow stabilized at 166 cfs (107 mgd). The estimated inflow to the reservoir today, based on the flow past the upstream gauges yesterday, is 231 cfs (149 mgd). The raw water withdrawals from the reservoir today are averaging in the low to mid forty million gallons per day which is approximately 65 cfs. This means the sum of water released for the IFIM study and withdrawn to meet customer demands equals the inflow and the reservoir level should not change much today or probably tomorrow. The inflow will not decrease significantly by the time the consultant completes the 150 cfs stage and we reduce the release rate to 50 cfs so the reservoir level will recover several inches while that stage is underway. The reservoir level will recover even more if there is much rainfall in the Appomattox River watershed tomorrow and Wednesday.
There is one more segment of data gathering for the IFIM study and that is referred to as a Demonstration Flow Assessment or DFA. The DFA is a team-based study used for portions of a river that cannot be evaluated using transects to measure the physical nature of the river at selected locations. In the case of our study the DFA will be applied to a highly divided portion of the river below the Abutment Dam. This study will be run at four (4) different flow rates (40, 80, 120, and 190 cfs have been suggested) which will take several days. Once the team members have been identified for this study the work will be coordinated between their individual schedules and ARWA's ability to control the river flows.
Once the field data collection is complete, that information will be used to determine the effects of various release flows on the aquatic habitat in the river as well as other beneficial uses of the river (including public water consumption and recreation). All of this information will then be evaluated and included in the proposed release schedule that the Authority will submit to the Virginia Department of Environmental Quality (DEQ) as part of the request for a permanent modification of ARWA’s Virginia Water Protection Permit 01-1719.
Any action the DEQ decides to take concerning our requested permit modification will be advertised for public comment, and possible public hearing, before the record can be considered complete and sent to the State Water Control Board for approval. We will use this blog, and the ARWA website, to keep everyone interested in this process informed of what is happening concerning our request.
The Appomattox River Water Authority was formed in the 1960s to own/operate a regional water supply and sell drinking water to the cities of Colonial Heights and Petersburg as well as Chesterfield, Dinwiddie and Prince George counties. The information below is updated frequently to communicate current information on Chesdin Reservoir and its environment.
