The purpose of this rulemaking is to establish minimum flows pursuant to Section 373.042, F.S., for the Pithlachascotee River in Pasco County. The effect of the rule is to support the District’s water supply planning, water use permitting, and ...

 

WATER MANAGEMENT DISTRICTS

Southwest Florida Water Management District

RULE NO.:RULE TITLE:

40D-8.041Minimum Flows

PURPOSE AND EFFECT: The purpose of this rulemaking is to establish minimum flows pursuant to Section 373.042, F.S., for the Pithlachascotee River in Pasco County. The effect of the rule is to support the District’s water supply planning, water use permitting, and environmental resource permitting programs.

SUMMARY: Section 373.042, F.S., requires the District to establish minimum flows and levels for water bodies located within the District’s boundaries. This rulemaking is necessary to establish a rule setting the minimum flows for the Pithlachascotee River in Pasco County. The establishment and periodic evaluation of minimum flows is required by statute to ensure that the minimum hydrologic requirements of the water resources and ecology of this system is maintained. The minimum flows for the Pithlachascotee River are being developed using previously peer-reviewed, Governing Board adopted methods.

SUMMARY OF STATEMENT OF ESTIMATED REGULATORY COSTS AND LEGISLATIVE RATIFICATION:

The Agency has determined that this will not have an adverse impact on small business or likely increase directly or indirectly regulatory costs in excess of $200,000 in the aggregate within one year after the implementation of the rule. A SERC has not been prepared by the Agency.

The Agency has determined that the proposed rule is not expected to require legislative ratification based on the statement of estimated regulatory costs or if no SERC is required, the information expressly relied upon and described herein: The District conducted an economic review of the revisions to the rule and determined that the impact or regulatory cost, if any, of the revisions will not exceed any one of the economic analysis criteria in a SERC as set forth in Section 120.541(2)(a), F.S. The revised minimum levels for this spring run is unlikely to constitute an additional significant regulatory constraint on groundwater or surface water withdrawals in the area due to existing resource conditions and regulatory constraints in the basin.

Any person who wishes to provide information regarding a statement of estimated regulatory costs, or provide a proposal for a lower cost regulatory alternative must do so in writing within 21 days of this notice.

RULEMAKING AUTHORITY: 373.044, 373.113, 373.171, FS.

LAW IMPLEMENTED: 373.036, 373.042, 373.0421, 373.086, 373.709, FS.

IF REQUESTED WITHIN 21 DAYS OF THE DATE OF THIS NOTICE, A HEARING WILL BE SCHEDULED AND ANNOUNCED IN THE FAR.

THE PERSON TO BE CONTACTED REGARDING THE PROPOSED RULE IS: Doug Leeper, MFL Program Lead, 2379 Broad Street, Brooksville, FL 34604, [e-mail], [phone] or 1(800)423-1476 (FL Only) ext. 4272. 2017066-4

 

THE FULL TEXT OF THE PROPOSED RULE IS:

 

 

40D-8.041 Minimum Flows

(1) through (19) No change.

(20) Minimum Flows for the Lower Pithlachascotee River.

(a) For purposes of this rule, the Lower Pithlachascotee River in Pasco County, FL includes the watercourse from the bridge across the river at Rowan Road (Pasco County Road 77) to the Gulf of Mexico, and tributaries to the watercourse segment.

(b) Minimum Flows for the Lower Pithlachascotee River are based on the adjusted flow at the U.S. Geological Survey Pithlachascotee River near New Port Richey, FL Gage (“Gage No. 02310300”) and are set forth in Table 8-25. Adjusted flow is defined as flow that would exist in the absence of withdrawal impacts. There are two flow-based Minimum Flows that were developed using average four-day flows at Gage No. 02310300 adjusted for withdrawals, with a long-term average of 27 cubic feet per second (“cfs”) for the period of record from June 22, 1989 through December 31, 2000. The total reduction in flow from the adjusted flow shall not exceed twenty-five percent of the previous four day’s average adjusted flow when the previous four-day’s adjusted flow is less than or equal to a Minimum High Flow Threshold of 60 cfs at Gage No. 02310300, and shall not exceed thirty-five percent of the previous four day’s average adjusted flow when the previous four-day’s adjusted flow exceeds a Minimum High Flow Threshold of 60 cfs at Gage No. 02310300.

Table 8-25 Minimum Flows for the Lower Pithlachascotee River at the U.S. Geological Survey Pithlachascotee River near New Port Richey, FL gage (No. 02310300)
Period	Effective Dates	Where the Adjusted Average Flow for the Preceding Four Days Equals:	Minimum Flow Is:
Annually	January 1 to December 31	60 cfs	Previous four day’s average adjusted flow minus 25%
Annually	January 1 to December 31	>60 cfs	Previous four day’s average adjusted flow minus 35%

 

(c) Status assessments of the Minimum Flows for the Lower Pithlachascotee River will be completed to determine whether the long-term, four-day average flow is below or projected to fall below the criterion adopted in this rule. Each status assessment is independent from and not a determination of water use permit compliance or environmental resource permit compliance. Permit compliance is a regulatory function that is not within the scope of this rule subsection. As part of each status assessment, the District will use the following approach:

1. The District will evaluate flows in the Lower Pithlachascotee River annually to: determine the extent to which the long-term average of four-day average flows in the Lower Pithlachascotee River has been reduced due to withdrawals for the period of record from June 22, 1989 to the date of each status assessment at Gage No. 02310300.

2. The District will also evaluate flows in the Lower Pithlachascotee River every five years as part of the regional water supply planning process.

3. If the Minimum Flows are being met based on the long-term average of the four-day average flows at Gage No. 02310300, then no further actions are required beyond continued monitoring.

4. If the long-term average of the four-day average flows at Gage No. 02310300 is below the Minimum Flows, or if the long-term average of the four-day average flows is projected to fall below the Minimum Flows within 20 years based on the evaluation performed as part of the regional water supply planning process, the District will conduct a causation analysis to evaluate the potential causes of impacts to flow in the Lower Pithlachascotee River. 

5. Based on the causation analysis, the District will re-evaluate the Minimum Flows for the Lower Pithlachascotee River, or adopt a recovery or prevention strategy consistent with the provisions of Section 373.0421(2), F.S.

(21) Minimum Flows for the Upper Pithlachascotee River.

(a) For purposes of this rule, the Upper Pithlachascotee River in Pasco County, FL includes the watercourse from the outlet of Crews Lake to the bridge across the river at Rowan Road (Pasco County Road 77), and tributaries to the watercourse segment.

(b) Minimum Flows for the Upper Pithlachascotee River are based on the adjusted flow at the U.S. Geological Survey Pithlachascotee River near New Port Richey, FL Gage (“Gage No. 02310300”) and are set forth in Table 8-26. Adjusted flow is defined as flow that would exist in the absence of withdrawal impacts. There are three seasonally dependent, i.e., block-specific, Minimum Flows that were developed based on daily average flows at Gage No. 02310300 adjusted for withdrawals, with a long-term average of 27 cubic feet per second (“cfs”) for the period of record from June 19, 1989 through December 31, 2000. In addition, the Minimum Flows are flow-based. The Minimum Low Flow Threshold is applied continuously regardless of season. No surface water withdrawal will be permitted that would cumulatively cause the adjusted flow to be reduced below the Minimum Low Flow Threshold of 11 cfs. Additionally, permitted surface withdrawals shall cease when flows are below the Minimum Low Flow Threshold of 11 cfs. In addition, the total reduction in flow from the adjusted flow on any given day from June 24 through October 16 shall not exceed sixteen percent of the previous day’s adjusted flow when the adjusted flow is less than a Minimum High Flow Threshold of 50 cfs at Gage No. 023103300 and shall not exceed nine percent of the previous day’s adjusted flow when the adjusted flow equals or exceeds a Minimum High Flow Threshold of 50 cfs at Gage No. 02310300.

 

Table 8-26 Minimum Flows for the Upper Pithlachascotee River at the U.S. Geological Survey Pithlachascotee River near New Port Richey, FL Gage (No. 02310300)
Period	Effective Dates	Where the Adjusted Flow on the Previous Day Equals:	Minimum Flow Is:
Annually	January 1 to December 31	11 cfs 11 cfs and 50 cfs ≥ 50 cfs	Actual flow Seasonally dependent – see Blocks below Seasonally dependent – see Blocks below
Block 1	April 25 through June 23	11 cfs 11 cfs	Actual flow Previous day’s adjusted flow minus 18% but not less than 11 cfs
Block 2	October 17 through April 24	11 cfs 11 cfs	Actual flow Previous day’s adjusted flow minus 17% but not less than 11 cfs
Block 3	June 24 through October 16	11 cfs 11 cfs and 50 cfs ≥50 cfs	Actual flow Previous day’s adjusted flow minus 16% but not less than 11 cfs Previous day’s adjusted flow minus 9% but not less than 11 cfs

 

(c) Status assessments of the Minimum Flows for the Upper Pithlachascotee River will be completed to determine whether the long-term, daily average flow and the daily average flows are below or projected to fall below the criteria adopted in this rule. Each status assessment is independent from and not a determination of water use permit compliance or environmental resource permit compliance. Permit compliance is a regulatory function that is not within the scope of this rule. As part of each status assessment, the District will use the following approach:

1. The District will evaluate flows in the Upper Pithlachascotee River annually to: determine the extent to which the long-term average of the daily average flows of the Upper Pithlachascotee River has been reduced due to withdrawals for the period of record from June 19, 1989 to the date of each status assessment at Gage No. 02310300; and to determine whether daily average flows at Gage No. 02310300 have been reduced below 11 cfs due to surface water withdrawals.

2. The District will also evaluate flows in the Upper Pithlachascotee River every five years as part of the regional water supply planning process.

3. If the Minimum Flows are being met based on the long-term average of the daily average flows at Gage No. 02310300, and based on the determination that surface water withdrawals have not reduced daily average flows at Gage No. 0230300 below 11 cfs, then no further actions are required beyond continued monitoring.

4. If the long-term daily average flow at Gage No. 02310300 is below the Minimum Flows or if the long-term daily average flow is projected to fall below the Minimum Flows within 20 years based on the evaluation performed as part of the regional water supply planning process, the District will conduct a causation analysis to evaluate the potential causes of impacts to flow in the Upper Pithlachascotee River.

5. Based on the causation analysis or the determination that surface water withdrawals have reduced daily average flows at Gage No. 02310300 below 11 cfs, the District will re-evaluate the Minimum Flows for the Upper Pithlachascotee River, or adopt a recovery or prevention strategy consistent with the provisions of Section 373.0421(2), F.S.

Rulemaking Authority 373.044, 373.113, 373.171 FS. Law Implemented 373.036, 373.042, 373.0421 FS. History–New 10-5-74, Amended 12-31-74, Formerly 16J-0.15, 40D-1.601, Amended 10-1-84, 8-7-00, 2-6-06, 4-6-06, 1-1-07, 11-25-07, 2-18-08, 3-2-08, 5-12-08, 5-10-09, 3-23-10, 3-28-10, 7-12-10, 8-2-10 (8), 8-2-10 (15), 10-16-12, 3-20-13(16), 3-20-13(17), 6-20-16, 3-15-18, __.

 

NAME OF PERSON ORIGINATING PROPOSED RULE: Southwest Florida Water Management District

NAME OF AGENCY HEAD WHO APPROVED THE PROPOSED RULE: Southwest Florida Water Management District Governing Board

DATE PROPOSED RULE APPROVED BY AGENCY HEAD: March 27, 2018

DATE NOTICE OF PROPOSED RULE DEVELOPMENT PUBLISHED IN FAR: April 13, 2018