Prioritization of the Designated River Segments Instream Flow Program
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Prioritization of the Designated River Segments Instream Flow Program NHDES 29 Hazen Drive, Concord, NH October 3 and 4, 2018 Designated Rivers All need Protected Instream Flow criteria and Water Management Plans Where to start? DES ranking 1. Cold – all – 23 miles 2. Warner – all – 20 miles 3. Isinglass – all – 17 miles 4. Oyster – upper and lower – 2+12 miles 5. Ashuelot – upper – 30 miles 6. Contoocook – upper – 12 miles 7. Saco – upper – 11 miles 8. Pemigewasset – upper and middle – 10+23 miles Prioritization criteria • Preliminary criteria in 2015 report rules – Upstream to downstream – Flow data availability – Development pressure – Strong public interest (LAC) • This assessment adds: – Funding limits – Gage quality and record quality – Complexity of WMP development Actions changing the criteria weighting • TFC – smaller parts of the DRs to assess for protected instream flows • QPPQ – gaps in a river’s stream flow gage record can be filled in with great accuracy • USGS – (under development) low-cost gages for management ExampleExample of TFC divisions Prioritization Goal to list DR segments in order of priority for next ISF studies • Upstream position is of first concern • An existing gage(s) is needed for management • Local support • Length and complexity must fit budget • Development pressure – high or low? • Gage record is (now) of less concern Steps • List rivers’ TFC segments (45) • Determine relative positions – U/S to D/S • Eliminate segments – done, tidal, no active USGS gage on river, downstream of two or more segments • Retain (16 on 12 rivers) and evaluate subjective criteria River section TFC Position Why Ammonoosuc River – Lower Lower Segment position is downstream Cocheco River – Lower Lower Segment position is downstream Connecticut River N/A Segment position is downstream and no TFC Contoocook River -- Lower Lower Segment position is downstream Contoocook River -- Middle Middle Segment position is downstream Contoocook River (North Branch) No Break Gage nonexistent or not suited for segment Exeter River - Squamscott -- Tidal Tidal Segment position is downstream; tidal Lamprey - Little River No Break Gage nonexistent or not suited for segment Lamprey - North Branch River No Break Gage nonexistent or not suited for segment Lamprey - North River No Break Gage nonexistent or not suited for segment Lamprey - Pawtuckaway River No Break Gage nonexistent or not suited for segment Lamprey - Piscassic River No Break Gage nonexistent or not suited for segment Lamprey River -- Lower Lower Done Lamprey River (New Lower Tidal) Tidal Segment position is downstream; tidal Mascoma River -- Lower Lower Gage nonexistent or not suited for segment Mascoma River -- Upper Upper Gage nonexistent or not suited for segment Merrimack River (Lower) N/A Segment position is downstream Merrimack River (Upper) -- Lower Lower Segment position is downstream Merrimack River (Upper) -- Upper Upper Segment position is downstream Pemigewasset River – Lower Lower Segment position is downstream Piscataquog River -- Lower Lower Segment position is downstream Piscataquog River (Middle Branch) Upper Gage nonexistent or not suited for segment Piscataquog River (North Branch) Upper Gage nonexistent or not suited for segment Piscataquog River (South Branch) Upper Segment position is downstream Saco River -- Lower Lower Segment position is downstream Souhegan River -- Lower Lower Done Souhegan River -- Upper Upper Done Swift River -- Lower Lower Gage nonexistent or not suited for segment Swift River -- Upper Upper Gage nonexistent or not suited for segment TFC divisions of the DRs (G&S, 2018) River TFC Segment 1 AmmonoosucList of River remainingUpper segments 2 Ammonoosuc River Middle 3 Ashuelot River Upper 4 Ashuelot River Lower 5 Cocheco River Upper 6 Cold River No Break 7 Contoocook River Upper 8 Exeter River No Break 9 Isinglass River No Break 10 Lamprey River Upper 11 Oyster River Upper 12 Oyster River Lower 13 Pemigewasset River Upper 14 Pemigewasset River Middle 15 Saco River Upper 16 Warner River No Break Qualitative assessments • Local support – LACs, others? • Gage quality - location relative to segment • Development pressure – percent vs absolute • Cost – effective use of funds, maximize length, and one or two segments/PISFs • Downstream this year, upstream next year Support • All but one of the remaining segments have active LACs • Public hearing process to come • Other considerations of support or opposition? Gage representativeness USGS gages Ranked by gage quality Existing 30 year flow record Gage potential for (3= complete 30 year SF Record management (0 = record; 2 = gap or short Quality Rank none, 1 = near, but record with supporting (location not well placed, 2 = gage(s); 1 = existing record and River section TFC Position gaged) < 20 years; duration) Ammonoosuc River Middle 2 3 6 Oyster River Lower 2 3 6 Pemigewasset River Middle 2 3 6 Ashuelot River Lower 2 2 5 Cold River No Break 2 2 5 Ashuelot River Upper 2 1 4 Contoocook River Upper 2 1 4 Isinglass River No Break 2 1 4 Saco River Upper 2 1 4 Warner River No Break 2 1 4 Ammonoosuc River Upper 1 3 3 Oyster River Upper 1 3 3 Cocheco River Upper 1 2 2 Exeter River No Break 1 2 2 Pemigewasset River Upper 1 2 2 Lamprey River Upper 1 1 1 Development Pressure Change in population in DR watersheds Development Pressure Nested development 2010 population pressure based TFC multiplied by on population 2010 Population / Sq. River section Position % change breaks Mile Ammonoosuc River Upper -- 0 0.15 Contoocook River Upper -2 0 129.44 Saco River Upper 44 0 0.89 Lamprey River Upper 69 0 172.36 Cold River No Break 281 1 61.22 Ashuelot River Upper 318 1 45.71 Pemigewasset River Upper 383 1 55.84 Oyster River Upper 593 1 716.48 Cocheco River Upper 689 1 235.93 Ammonoosuc River Middle 783 1 45.53 Warner River No Break 1527 2 82.33 Ashuelot River Lower 1922 2 121.81 Isinglass River No Break 2102 2 175.23 Pemigewasset River Middle 2566 2 29.34 Oyster River Lower 2611 2 818.16 Exeter River No Break 6435 2 404.97 High Low Medium Funding and Data • Available funding limits a PISF study budget to about 30 miles • TFC divisions provide smaller segments • Funds for flow records: missing records will be calculated using QPPQ. If flow records are to be calculated, then some funding must be taken from the PISF study budget (i.e., less than 30 miles) Decision on DR Rankings DR River River segment segments Development SF data length (determined by TFC project) upstream LAC Active pressure quality (miles) Ranking Cold River 0 Med Med High 23 1 Warner River 0 High-new High Med High 20 2 Isinglass River 0 Med High Med High 17 3 Oyster River -- Upper 0 Med Med Med Low 2 Oyster River -- Lower 1 Med High Very High 12 4 Ashuelot River – Upper 0 Very High Med Med High 30 5 Contoocook River -- Upper 0 High Low Med High 12 6 Saco River – Upper 0 None Low Med High 11 7 Pemigewasset River -- Upper 0 High Med Med Low 10 Pemigewasset River -- Middle 1 High High Very High 23 8 Ashuelot River -- Lower 1 Very High High High 35 later Ammonoosuc River -- Upper 0 Med Low Med Low 6 later Ammonoosuc River -- Middle 1 Med Med Very High 32 later Cocheco River – Upper 0 Med-new Med Low 7 later Lamprey River -- Upper 0 High Low Very Low 8 later Exeter River 0 Med High Low 41 later.