Loading...
HomeMy WebLinkAbout02-09-22 Documents Received from Abutters W. Warnock & B. EbertTOWN OF YARMOUTH y � rA C4i� REPORT ON GROUNDWATER RELATED FLOODING PROBLEMS OVERVIEW AND RECOMMENDATIONS Draft Submittal: September 2003 Prepared by: NORFOLK RAM GROUP ENGINEERING THE ENVIRONMENT One Roberts Road, Plymouth, MA 02360 TEL: 508-747-7900 Fax:508-747-3658 www,Norfo]kRam.com EXECUTIVE SUMMARY Overview The To wn of Yarmouth experiences seasonal outgroundwater the totwn and The severity of these flooding in a variety of residential areas throughout t on the annual problems varies considerably seasonally, from year mrareaeto area, depending upon the variability of meteorological conditions, an hic hydrologic, and hydrogeologic setting of the individual ofrsaEut ons for these m areas. The topographic, Y town's motivations to find a practical, cost effective inconvenience solution o he public d it prob lems are many. The flooding is a serious invironm iencono public health nand safety, potential for creating adverse affects investments (town roads andndrainage systems). Unfortunately, and on infrastructure the town's resources are not unlimited, and in addition thatoneed to be cons deredcost, there are ifwhen icant environmental, regulatory, and institutional constraints are these solutions cost rietermininp first, if any practiCal solutions exist, and if So, effective and achievable. The stated objective of this study has been to prepare a `Final Study„ (within the practical limits of the study budget) that will to rest trie ia reviewur faf the naturelooding rof ol feasibility within the Town of Yarmouth. study is based on these flooding problems town -wide, a review of the previous studies, and a practical analysis of possible technical solutions. This study identifies a set offfeas feasible and cost effective� solutions for the problem areas of greatest concern. The Y potential solutions has been based on a realistic assessment of the costs and funding options within the framework of the environmental and institutional constraints. The Study Process Grouping and Overview of Problom Aroas Through completion of previous studies, the town had identified twenty-one (21) areas that experienced varying degrees of flooding (see report Table 1.1, and for those areas most significantly affected, see report Figure 1.1 - Area Locus Map). After analysis of the physical setting of the problem areas (see report Section 3), the twenty-one areas were sorted into four groups based on geographic setting: 1. Flat low-lying communities along the south shore; 2. Flat elevated communities in the central area; 3. Hilly communities located chiefly in the central area; and 4. Elevated areas surrounded by wetlands along the north shore The flooding problems were then further grouped into the following two categories: Basement Flooding and Street Flooding. Basement Flooding occurs as a result of the water table intersecting the basement proper. In certain areas (particularly some low lying areas), the problem can be chronic, while in other areas the problem is strictly intermittent. In the Captains Village area, the homes that have intermittent basement flooding problems are all located at lower topographic elevations. Street Flooding Executive Summary for Yarmouth Report on Groundwater Related Flooding Problems main problems: Enclosed drainage basins areias th � Street eet flooding rainage eis results from two p Particularly in low lying in the underlying and/or inadequate drainage outlets, p via infiltration capacity) ' often a result of lack of space for flood storage (via aquifer system due to naturally high water levels and is most pronounced where depths to groundwater are a few feet or less. geology, The causation and severity of flooding was determilnedofrom he individual problem areas. topographic, hydrologic, and hydrogeologic setting (Engineering Department, Health Information sources included review of town recordsdengineering reports, and Department, Conservation Commission, etc.), previous refer to report Section 4, and discussions with the town officials. [For more details, Tables 4.1 and 4.2, and supporting Appendix A "Detailed Description Report for Each of ne Twenty-one Problem Ares"_] The evaluation of problem causation and severity far all identified problem areas was reviewed and confirmed through disuu55iona with the Town Engineer's office, priority The end result of these evaluatiun� w°° tl'O easntif tin of thirteen o eeelat �e� everit problem areas. These thirteen priority areas, grouped caiegarioe (pow. Low to te. Moderate, and Hi h were determined to have a problem severity significant enough to warrant more in-oeptri evaluation for ld ";f'fation of possible solutions. A detailed Study Area Plan was created for eachne of the with thirteen priority problem areas (see Sheets 1 through 13 in report map pockets), drainage tributary zones delineated on each plan along with any existing town drainage sySLCIlZS .. W� wcicr �ak� rlvwo a j il,nt nnntrlhlifa to flnndina during high groundwater periods were calculated for the 10-year and 25-year frequency storms (see report Table 4.3). The stormwater volumes were used to check the reported severity, and to evaluate possible engineering solutions for the flooded areas. Developing a Problem — Solutions Matrix An overall set of conceptual solution options was identified that would be applicable to the types of groundwater related flooding at the thirteen (13) problem areas. These sLIullUiIa WC[G d3,CtijUU Yt-,11ulally ao tv tl-iair -_n9inoQr;n9 fcasibility, cffeoiivon000 in solving (and not transferring) the problem, constructibility, probable cost, and environmental impact. These potential solutions were also reviewed for technical and environmental feasibility with assistance from the Town's technical advisory team. The initial effort resulted in a problem/causation — solution matrix (See report Table 5.1). in addition to developing problem -area specific solutions, the study included a limited but focused search of published articles, technical literature and internet sources in order to confirm that the existing engineering "state of the art" has not shifted significantly and to identify other municipal experience, and innovative / alternative control methods for stormwater and groundwater related flooding. The results of this literature research are presented in report Section 5.2 and Appendices D, G and H. Planning level cost estimates were then prepared to compare and rank the most practical and implementable solutions. The results of these detailed assessments were ES-2 Executive Summary for Yarmouth Report on Groundwater Related Flooding Problems presented to the TownIsadvisory team as a set of problem area memoranda and study maps. Possible solutions, and implementation priorities (in some cases several possible and increasingly more expensive solutions) were presented for each of the problem areas. After several town reviews of these memoranda and study area plans, the specific problem area solutions and rankings were organized into report Table 5.2 - "Expanded Problem - Solution Matrix". The key report Section 5.4 - "Problem -Solution Analysis for Priority Problem Aram" ch area in report Table summaryared. The .3 f key recommended solutions and costs presented for ea Assessment of Environmental Impacts and Re u a orvConstraints Report Section 6 presents an analysis of the environmental impacts that may affect the feasibility of the various proposed solutions. The regulatory constraints and environmental impacts were formulated through meetings with government officials (Town of Yarmouth, DEP, EPA and MEPA), supplemented by review of existing federal, state and local regulations, and justified through limited on -site sampling and national data documenting the quality of groundwater, stormwater and basement sump pump discharges from residential areas. The local Conservation Commission and the Department of Environmental Protection would be responsible for permitting the majority of the floodwater improvement projects through issuance of an Order of Conditions under the Wetlands Protection Act. In cases where discharge is proposed to surface waters proximate to sensitive receptors such as areas tributary to shellfish areas or Zone 11 Aquifer Protection Areas, permitting authority may fall to the DEP under The Massachusetts Clean Water Act and 314 CMR 3:00, Surface Water Discharge Permit Program. However, given the residential setting of the project sites and the quality of the stormwater, regulatory approvai for detention basins and subsurface storage & infiltration facilities under the Massachusetts Ground Water Discharge Permit Program and review pursuant to the Massachusetts Environmental Policy Act, was not deemed necessary. Major Study Findings O bons that ware considered but eliminated as not feasible. Certain solution options were considered but eliminated as not technically, environmentally or fiscally feasible. These include: ■ Area -wide lowering of groundwater table ■ Low-pressure sump -pump sewer systems ■ Basement pumping, and ■ Installation of relief wells General Recommendations The following General Recommendations, discussed in more detail in report Section 7, have been developed for implementation: The Town of Yarmouth should consider adopting Stormwater, Grading and Drainage Control bylaws and should develop a public education and/or financial assistance outreach program to provide information and encourage homeowner adoption of low - impact re -development solutions that help to prevent stormwater from reaching town ES-3 Executive Summary for Yarmouth Report on Groundwater Related Rooding Problems streets. The town should also consider a general Lad B n that these purchase strareategy can for the systematic acquisition of lots in low-lying flooded areas modified for drainage benefits andlor restated to a natural treatment and slow release of with associated benefits and resource values for stora9e floodwaters in the problern areas. At a minimum, the town should implement construction of tof the age st ra ea& recharge facilities that have been recommended particularly in em ars, Expanding the use of stormwater capture, uwill help storage to prevent stogmwate� from migrating to outlying portions of the tributaryaras the severely affected, lower lying flood zones within each under le Problem A ea GenerallySpec fic , this work should precede any other work noted below Recommendations% and it should be preceded by confirmatory work to map and assess existing drainage systems, high groundwater interactions aater ccritical elel elements should vations and to further refine the cost estimates. All of the selected storm be incorporated into the town's plan for compliance with the EPA Phase ll NPDES Stormwater General Pern-iit program. are In areas where larger catchment areas and the increased tot newlooutfalls proposed to existing outfalls (i.e. Plashes Brook and Plashes (i.e. Iroquois, Crowes Purchase, and Pheasant Cove) the town should add BMPs to existing structures or prior to new outfalls to reduce currentpollutant loadsue ga and offset and the additional loading from the new sources. The town should test sump -pump water, stormwater and/or floodwaters en�{ spbased loin es aamore complete rise in order to ensure that decision -making on floodwater management e and regularly updated testing database and to provide water quality data to aid in the selection of BMP controls. /�N,va ovlut;ona polling for pnrtahlP. Pmeroenu DUMP6 could share pumping units with other similar areas with the town initially renting or leasing the emergency pumping ulilt5 to develop experience prior to making any capital investments in pumping equipment. On -Site homeowner based Solutions On -site low -impact development and stormwater control soluti ns include the These e Of rain gardens, rain barrels, green roofs, and reducing Imp ervious approaches are considered to be most applicable to the Yarmouth problem areas where groundwater is typically Nigh and recharge to subsurface dry wells and leaching trenches can, during certain wet seasons, be of little value. In addition, some of the homeowner -based strategies represent some of the lowest cost viable solution options for helping to prevent flooding in all of the areas studied. Rather than allowing rainwater to run off developed property into streets and storm sewers, these devices capture some of the water as a resource for later reuse, or at least to allow it to gradually soak into the ground and recharge the groundwater. Homeowners could also use Rain Gardens to receive, store, and process sump pump discharges. Problem -Area Specific Recommendations Please refer to Table ES-1 Summa of Problem Area Recommendations, in this Executive Summary, for recommendations for each of the specific problem areas. See report Section 7.4 for a more detailed description of each of the problem areas with ES-4 Executive Summary for Yarmouth Report on Groundwater Related Flooding Problems emphasis and clarifications on key aspects of the recommended solutions, along with comments on the key environmental issues that affect each area. It is assumed that the "Problem -Area Specific Recommendations" will be implemented after the "General Recommendations" have been implemented. These area specific recommendations basically fall into four general categories of improvements: (1) Installation of catch basin -leaching structures in outlying areas to reduce the influx of stormwater to low lying areas, (2) the construction of new (or expansion of existing) stormwater detention basins to provide off-street storage of floodwater, (3) BMP enhanced stormwater outfalls, and (4) emergency pumping facilities to pump excess floodwater to new storage and recharge facilities. Funding Optiorls It is important to note that the cost estimates presented in this report are benchmarked to September 2002, and are subject to change in the future. In general, there are two sources of funding that may potentially be applicable for implementation of the General and Area -Specific Solutions presented in this report: (1) local funds (i.e. homeowner -taxpayer based), and (2) state & federal funds (grant or loan based). A detailed review of funding sources and financing mechanisms for these municipal improvements should be developed as part of an overall stormwater 1 floodwater management implementation plan that would be based on key policy decisions that are ultimately made bythe sc Board of f each Selectmen of #hethrough pate tial funding Meeting process, A more detailed d mechanisms is included in Section 7.5. Potential local funding options include the Roadway Management Program (RMP) — (an existing source based on RMP Bonding and state Chapter 90 funds); Drainage Capital Funds (an existing source based on bonding and general tax revenue); the Cape Cod Land Bank (an existing source based on real estate tax surcharge); Stormwater Utility Funding (an as yet un-established source would require the. establishment of either a town -wide self funded stormwater utility or several limited "area -specific" stormwater utility districts that would develop, manage, and pay for stormwater and floodwater control projects within the town); and Community Preservation Act (CPA) funds (an as yet un-established source that would require town adoption of the state backed CPA program that involves a 3% surcharge on real estate taxes). Potential state and Federal funding mechanisms include Clean Water State Revolving Fund Program (low -interest loans, currently 2%, that are available for stormwater improvement projects that implement BMPs for non -point source pollution control); 319 Stormwater Implementation Grants (grant funding available for stormwater improvement projects that implement BMPs for non -point source pollution control); 603(b) Planning Grants (grants that may be available for funding more detailed planning and design efforts for implementation of the town's NPDES Phase II Stormwater Management Plan); Coastal Zone Management Funds (loans and grants for projects involving the elimination or BMP improvement of stormwater systems that discharge to coastal wetlands or tributaries to coastal wetlands); Conservation Grants (utilized to support ES-5 Executive Summary for Yarmouth Report on Groundwater Related Flooding Problems Open Space land purchases, e.g. lots subject to flooding); and federal HUD Community Development Block Grants (grants which may be available to fund projects in several of the problem areas provided that Program income restrictions are met). ES-6 saaeds (Mejo 0j :januoa 'pool} }ey; sJuawases uopusgd x x sooe}ang algeawjadwl to a0npe-d 'suapje� ulea x x x x Is1'slajje8 uiea Swalsfis j0;0a1100 japm dwns ainssaad x Mol 'Seaje IVORIJa WOJ} leleMpunoJB dwnd pulageM jo1pue 'uol;ualep'6ul43e0; x x x o; JaleMwjols dwnd 0 sea -le A0410 01 na`OU o to looilpaJ - saleMg dW9 x x x jo sulejp wjo;s MaN 0 -F SAs FaBivauilwipO f4joedeo x xx 0Mau lle;sulglj# eonpaa 86ejoIs uo!IuaIap x x jo;eseyojnd I:Jadojd BulpejB-aj pue r, `S401 eBeuleap (Bul;slxa x x puedxa) Meu emo-I Buldwnd x x r� joeils IC3uatijaw3 r Buldwnd dwng x x w C d 7 GI.d L C1 d aO+ � yH yI N o G y C qs G1 ro a a c o -a0 d y c to C) c vi �'CA v C fl to rnL n�+ Om c0 g '0 :a G 4s T Q to y+ 0. CL 0.ill Cram, IV Cc E C C1 G C N 'C y d 0 y s. 'C vL+ O S1S in N G. 0 c a w t7 .0 m u c E ro m c a o � L C. 0. N c y c 0 3 7 � � o v ? E d 3 cs E E FA E' R L U O 04)m H y b CD V ' o � Q 2 c o S°CD � o U Q vi o E o E 3 � 4c 0-00�8f N w «. v O N U 3 c6 0 .+ M m M H c0 Q- 5 't c�� ca._m a) E :5 , o 03. ai I-c`� E ° o rn E E N v O k-i M 0 m .ca E 2 .. c� O c i2 a 0 C9 E ro C2 19 ptt 0 Z a m a aw s4 1-- TABLE ES-1 SUMMARY OF PROBLEM AREA RECOMMENDATIONS area Area Nama---T---- Recommended solutions Capital Costs Itt Annual 0"' Is) No. Areas with Severity Rated High Install 30 catch basin -leaching structures. Purchase 2 undeveloped lots to increase off- $g34,850 $14,400 2 VINEYARD street storage. Build facilities to pump excess floodwater to subsurface storage & (see sheet 1 of 13) recharge facilities to be constructed at town parking lot. Install 18 catch basin -leaching structures. Purchase 3 undeveloped lots & one house lot $992 200 $11 900 7 ANASTASIA to increase off-street storage. Build facilities to pump floodwater to a new storage & (see sheet 5 of 13) recharge facility to be constructed at Tabor Road. Purchase 2 home sites that flood, increase off- 6toaece $933,200 $8,800 13 MULFORO STREET (see sheet 7 of 13) s1sBel� 9 and raisecMulgford Street. Purchase 4 home sites that flood and convert to Increased off-street storage, and lots to provide increased off street storage (both storage areas $1,908,775 $15,600 CAPT. VILLAGE purchase 4 undeveloped raising road grades). Build facilities to pump excess floodwater to existing town 15 (WEST) (see sheet S of 13) require drainage lot. (Emergency pump solution coordinates with Captain's Village East improvements). Subtotal of Estimated Costs for Areas Rated High Severity = $4,768,825 $50,700 Areas with severity Rated Moderate Install 6 catch basin -leaching structures. Build facilities to pump floodwater to new BM $198,540 $3,200 IROQU015 4 (see sheet 2 of 13) swale with outlet to nearby town conservation land. CAPT. VILLAGE Install 10 catch basin -leaching structures. Increase off-street storage at two existing town Build facilities to pump floodwater to new subsurface storage & recharge $1514,350 $8,900 14 (EAST) drainage lots. facility to be constructed at the Dennis -Yarmouth Regional School. (Emergency pump West Mulford Street improvements). (see sheet 8 of 13) solution coordinates with Captain's Village and Subtotal of Estimated Costs for Areas Rated Moderate SeverM-- Areas with Severity Rated Low to Moderate CROWES PURCHASE �r,100 Install 15 catch basin -leaching structures. Remove pavement, re -grade to eate EM,500 5 (see sheet 3 of 13) drainage swale to relieve flooded area. JOHNSON SHORE5 6 Install 4 coach basin -leaching structures. ,1,400 (see sheet 4 of 13) O PLASHES BROOK Install 12 catch basin -leaching structures. Purchase 2 undeveloped lots to expand existing town drainage lot for increased off-street storage. Build facilities to pump excess $525,700 $6,700 t2 (see sheet 6 of floodwater from BMP basin to existing outfall (to Plashes Brook). 16 !PLASHES POND �to ln5t1110catch basin -leaching structures, guild off-straot storage at existing town [at. with140,600 $4,760 lIrflowviaexisting drain structures to Plashes Pond. Build facilities to pump floodwater $(see sheet 10 of 13} existing Town drainage lot improved with BMP for outfall to Plashes Pond. 17 PRESIDENTIAL (see sheet 11 of 13) Town has installed extensive system of leaching drainage structures with outlet piping. installation of additional structures is not appropriate. No recommended improvements. Subtotal of Estimated Costs for Areas Rated Low to Moderate Severity = $0 $841,700 $0 $19,300 Areas with Severity Rated Low. 20 Lookout Road Install 4 catch basin -leaching structures. $28,560 $1,400 (see sheet 12 of 13) Pheasant Cove Install 4 catch basin -leaching structures. Re -grade roads in two areas and direct drainage $116,600 $1,800 21 (see sheet 13 of 13) toward two new BMP drainage swates, prior to release to wetlands (land bank property). Subtotal of Estimated Costs for Areas Rated Low Severity = $145,160 $3,200 Total for All Problem Areas with Recommended Solutions = $7,468,575 $85,300 (1) Public Bid Costs. Lard Cost - 2xAssessor Value. sea Table 5.4 delails. Norfolk Ram Group - Final Draft, September 2003 (g) 0 - M wet: Catch Basins - 7% of wnst.ly<. Dot. Basins sales = 10%ofconsilyr Table 5.2 Expar Problem / Causation __T Area a�b AREA NAME AND TYPE Go��•� a� ��i� you +`y+� Solution Number 1 1 2 1 3 SOUTH SHORE FLAT LOW LYING AREAS - Street & basement flooding in low-lying 1 high ws 2 VINEYARD X X 2 X 2 4 IROQUOIS X X 3 X 2 ; 5 CROWES PURCHASE X 1 RUN POND X 3 PAWKANNAWKUT X 8 BAYBERRY X 9 BERRY X CENTRAL FLAT ELEVATED AREAS - Street and/or basement flooding due to high water tabl( 7 ANASTASIA X X 2 X 2 6 JOHNSON SHORES X 12 IPLASHES BROOK X X 3 X 2 16 PLASHES POND X 17 PRESIDENTIAL X 11 FOREST ROAD / RT28 CENTRAL HILLY AREAS - Street and/or basement flooding due to closed drainage depressio 13 MULFORD STREET X X 2 15 CAPTAIN'S VILLAGE (WEST) X X 2 X 2 14 CAPTAIN'S VILLAGE (EAST) X X 3 X 2 J 14 BAXTER X 18 NO. DENNIS/GREAT WESTERN X 19 OXFORD STREET NORTHERN AREAS - Basement and minor street flooding due to seasonal high water table, I, 20 LOOKOUT ROAD X X 21 PHEASANT COVE X X 2 * Bold X t indicates solution preference, with X 1> X 2> X 3> X Other large-scale solutions that would help to address street and basement flooding problems includ 1. Establish zoning requirement that all new basements be constructed above seasonal high grounc 2. Construct neighborhood sewer systems with decentralized treatment to eliminate / relocate groun 3. Implement a Public Outreach - Education and Assistance Program to encourage homeowners to im - Solutions Matrix 'lutions (with ranking of preference*) t vat �t0a� �cc o���� e` �a acb`° e���°e a6 44+°e aooe aVa�` D oo Y�C6 ��. 0y to 1,a x0 a a� G" Q ewe yQ' ea Pie �,e <° 5 �0 �p`� b � o4 ear c� el ` KP b� °c O� � ce` ¢ �e ee ��' Ge a 4 �e� o b � at y�o bey �e� oJ� eae, te5 4�°c �,�c eati eat �a ova aQa �G®� G�� �p� Uziibl` o� G 5 B 7 8 9 10 Severity Rating is, ponding in closed drainage depressions X I X 2 X i X 3 HIGH X 7 X 2 X 3 X 1 X 3 MODERATE X I x 2 x 9 X 3 MODERATE X X LOW X X LOW X X LOW X X LOW closed drainage depressions, proximity to seasonal stream flooding XI X3 Xi X3 HIGH X X X LOW to MODERATE X I X 3 X I X LOW to MODERATE X 1 X 2 X X X LOW to MODERATE X X LOW to MODERATE X LOW onal high water table In/near depressions X 1 X 3 X 1 X 3 HIGH X7 X2 X3 X X1 X3 HIGH X 7 X 2 X 3 X X 1 X 3 MODERATE X X LOW X X LOW X LOW le soil substrate, ponding in closed depressions X X X 1 X LOW to MODERATE X I X 2 X t X LOW to MODERATE •ge from septic systems. :se and other low -impact re -development options at their home sites. Norfolk Ram Group - Final Draft, September 2003 CATCH BASIN -LEACHING SYSTEMS TABLE 7.2 RECOMMENDED Number of Recommended Estimated Estimated Area Area Name Catch Basins with Leaching Structures Capital Costs c1i Annual 0&M No. Areas with Severity Rated High VINEYARD 30 systems; (see Table 5.3 for complete $150,000 $10,500 2 (see sheet 1 of 13) assessment of costs). ANASTASIA 18 systems; (see Table 5.3 for complete $90 000 $6,300 7 (see sheet 5 of 13) assessment of costs). MULFORD STREET 6 systems; (see Table 5.3 for complete $30,Q00 $2,100 13 (see sheet 7 of 13) assessment of costs). CAPT. VILLAGE NONE RECOMMENDED FOR THIS AREA $0 $0 15 (WEST) see sheet 9 of 13) _ Subtotal for High 5everi $270,000 $18190 Areas with Severity Rated Moderate IROQUOIS 6 systems; (see Table 5.3 for complete $30,000 $2,100 4 (see sheet 2 of 13) assessment of costs). CAPT. VILLAGE 10 systems; (see Table 5.3 for complete $50,000 $3,500 14 (EAST) assessment of costs). (see sheet 8 of 13) Subtotal for Moderate Severs $ 80,000 $5,600 Areas with Severity Rated Low to Moderate CROWES PURCHASE 18 systems; (see Table 5.3 for complete $90,000 $6,300 5 (see sheet 3 of 13) assessment of costs). JOHNSON SHORES 4 systems; (see Table 5.3 for complete $20,000 $1,400 6 (see sheet 4 of 13) assessment of costs). PLASHES BROOK 12 systems; (see Table 5.3 for complete $60,000 $4,200 12 (see sheet 6 of 13) assessment of costs). PLASHES POND 10 systems; (see Table 5.3 for complete $50 000 $3,500 16 (see sheet 10 of 13) assessment of costs). 17 PRESIDENTIAL NONE RECOMMENDED FOR THIS AREA $0 $0 (see sheet 11 of 13) Subtotal for Low to Moderate Severity $220,000 $15,400 Areas with Severity Rated Low Lookout Road 4 systems; (see Table 5.3 for complete $20,000 $1,400 20 (see sheet 12 of 13) assessment of costs). Pheasant Cove 4 systems; (see Table 5.3 for complete $20,000 $1,400 21 (see sheet 13 of 13) assessment of costs). Subtotal for Low Severity $40,000 $2,800 Total = $610,000 $42,700 (1) Public Bid Costs. (2) 0 + M cost = 7% of Capital Cost Table Page 1 of 1 Norfolk Ram Group -Final Draft, September 2003 U3 W U3 IL 0 z 0 LU W 0 W w LL N M ti W J m H �O O Q �? NO M 04 r C N ; N l[S dT _ c? ti tl� cT*� cr7 co w Fa- ao O a O Co 's? Q p � o O CV U) N N p CV LO coC 6F3 !p U o 0 0 �? o � Q O � N CO N tf 3 M cf) p O n r kn O M UC14 CO 6q*- Oct N � p 0) cn a)D (a1 p 0 M co N N CF7 N X O a) N @ L- O 0 a 0 N m a) c � ( °� ay3 r C d] W E c � . CL v o 0 0 -o a) CL c c 7 > > C U) > O a = D p p © N d U r' O L Q CV y N D V v C _ a a o E _ Q 2 J ,J m O z w w 5 R c � f• c i w i `m as O com sr, 4- w m o H z U)° a cn o C7 o ¢ Us U) o m a�i cn a u, ti a, L Q as Q a) a> j �. 3 U, m N �" c11 U) N O fA F— j N N N Co.N U) za ¢a �a ¢W a fa m LD R E C E I V E D EFE:80 9 1922 YARMOUTH BOARD OF APBEA(.S Owner Lot Number Comments Ebert 311171 Known to have seasonal water flooding issues in basement. Warnock 311172 Known to have seasonal water flooding issues in basement. Santora 31 /173 Known to have seasonal water flooding issues in basement. Faqaharson 31/174 Known to have seasonal water flooding issues in basement. Burokas 311175 Known to have seasonal water flooding issues in basement. Butler 311208 Known to have seasonal water flooding issues in basement. emu._�u t Q m am a= k,c-"�� a-:--L :.'..' S� fir-+° � '1 '•' � sl r `_'�J��� v i,•_.AA, y+^r �* T _ µ � �r"d! F"°y'�i 'n a Ay \ } It ? " _` �T' Ss ` r. uj Cw UJ mLLJ Q LLco }I v ym� ID T•p A'-ze._. p _ a �*,p � II �I g �� '•\ �� � �' fir" d < =H p ..� � I l` �arjj � A16,� y, � ) bo ,.��- - ����-''''� to l � �AYr�...�i'r ' �j .l •\ ,• •'�� -� C, .ti. � Q ~'Yoh { { o ��_. L+�.�. Je O i �[ / # ter'-S ir ' 1. • �, 0. �'�� x` z : •a� i �� # � ; � • s � yet--._. -.-�� 1y��� r`�} (Zg} uj lam.. 1. � � 4 j•'s� \ � � � � I '� � � J •r • � _ � y I, fl+s}►� -..'�, I , Y 8 � S 1�--i � loll OVERVIEW AND RECOMMENDATIONS NORFOLK RAM GRoup Study of Groundwater Related Flooding Problems PRESENTATION (Report Overview) • Norfolk Ram Group, LLC (Plymouth) - Mark S. Bartlett, P.E. (Principal, Project Manager) • Representing the Town • George R. Allaire, P.E., Director of Public Works • Rick deMello, P.E., Town Engineer NOWDIA Juiy 2004 2 1 Study of Groundwater Related Flooding Problems TONIGHT? • General Town -Wide Meeting • Obtain further public input & comments REPORT OVERVIEW • Brief Overview of Study and Results • Recommendations — phased approach • Funding Sources - discussion After Tonight? ONE (1) MORE MEETING • Report back to Yarmouth Selectmen July 2004 Study of Groundwater Related Flooding Problems PROBLEM? • Street, yard, basement flooding (some residential areas) . Severity Varies • Year to Year • Seasonally • Depends on Water Table Level, Hydrogeology & Precipitation Town Motivation to Solve? • Serious Inconvenience • Potential Public Health and Road Safety Issues • Environmental Concerns 2 Study of Groundwater Related Flooding Problems STUDY OBJECTIVES • Final Study - Flood Control Feasibility • Identify Areas of Greatest Concern • Develop Set(s) of Feasible Solutions • Are there any? • Are they Cost Effective? • Do Solutions Minimize Environmental Impact? July 2004 f'> R A �� EDP '- 5 Study of Groundwater Related Flooding Problems 21 PROBLEM AREAS REDUCED TO 13 PRIORITY AREAS (identified for Detail Study) 1. Run Pond Road 12. Plashes Brook 2. Vineyard Street 13. Mulford Street 3. Pawkannawkut Drive 14. Captains Village East a. Iroquois Boulevard s. Crowes Purchase Road 15. Captains Village West B. Johnson Shores (8mberry La.) 16. Plashes Pond 7. Anastasia Road 17. Presidential Area a. ­-9— berry Road 18. No. Dennis Rd. 1 W. Great s. Berry Avenue Western Road 1o. Baxter Avenue 19. Oxford Road 2o. Lookout Road 11. Route 281Forest Road 21. Pheasant Cove Circle Jury 2004 `::<.:+ 6 J n -- . ,.:.>•-. -: a:. a."sa- e.-.-:..;.;f f-t w, 1F:, .. .:: ::.---:::: .:.. iNfx6s a.,: .::_::Y i. :axt :xic <,.:-f<— f .;, S} Xsgao 3.4-Rarharyab Eisgrarhy5smaves duwtxerd ixhlhe aquikrand.fhmhorimt+ta4ybaadi wtrs(W»red r Off t. i.e.-.-.<rix. .. moves eyt�dendcrB'sdutgad: Coi�frtitg vets oietcnatifofofiy,.s+l..and�Y(+t�sm+dFm'ftha ubnrnim�n'movammtof i..-,•. ,! - ... .... ��wternplaces and oHaet d'rieshxeRr-.vlxatxSauAttr.runmQ mx n.Csps God Bay.: 71+e 6x of AYesecOmxsshowi- t i � ... . -. Example of Research Results: - - Figure 3.4 .,.I:VerticaFGroundwaterFlow Net �� Vertical Groundwater Flow Net on as i Study of Groundwater Related Flooding Problems Flat Low-lying South Shore Communities (Vineyard, 104 Acres — see map on board) > LOW ELEVATIONS I HIGH WATER TABLE . Surface elevation range: just above sea level in outlying wetland areas, to approx. 12 feet above . Terrain of broad closed depressions (several), or flat or gently sloping toward adjacent water . Depth to high water table ONLY 0.9' and up . Seasonal water table changes, 2-ft . 2 main depressions collect storm water of about one (1) acre-foot in 10 year 24hr storm NORWI.-K. RAM GROUP July 2004 -- -- - Study of Groundwater Related Flooding Problems Central Flat Elevated Areas (Anastasia, 54 Acres — see display map) LOW ELEVATIONS I HIGH WATER TABL • Surface elevation range: 8' to 20' above sea level . Terrain of broad closed depressions (several), or flat or gently sloping toward adjacent water . Depth to high water table ONLY 2.5' to 5' and u . Water table fluctuations, 2' to 3' . 4 main depressions collect storm water, volume varies from 1I2 to 1 acre-foot in 10 yr-24hr storm r.:�ci�iaib�:3C July 2004 ...- ------ 5 Study of Groundwater Related Flooding Problems Central Hilly Areas (see display maps) Captains Village West - 71 acres Captains Village East - 83 acres Mulford Street Area - 12 acres > CLOSED DEPRESSIONS I HIGH WATER TABLE . Surface elevation range: 15' to 25' above sea level . Terrain of broad closed depressions (numerous) . Depth to high water table varies: 0' to >12' . Water table fluctuations, 3' to 5' . Depressions collect storm water*, volumes vary from 4 to 30 acre-feet of water depending on size *(10 yr-24hr storm) N"OR.$'(DtX July 2004 Study of Groundwater Related Flooding Problems SOLUTION OPTIONS (10) evaluated, for each area •Basement Sump Pumps (restrict, provide collection system?) Emergency Street Pumping (and, to where?) • Drainage Lots (build new or expand existing?) • Property Purchase (eliminate flood prone house lots, andlor provide new drainage lots?) • Reduce Tributary Area (install new catch basins w/ leaching?) • New Storm Drains, BMP Swales (redirectflow?) • Pump Stormwater (to leaching, detention, wetland?) • Pump Groundwater (from critical areas?) • On -Site Solutions (Rain Barrels 1 Gardens, less impermeable area?) • Abandon Basements (create crawl spaces for existing utilities?) July 2004 t#. d.. 12 Col Study of Groundwater Related Flooding Problems SOLUTIONS ELIMINATED Options considered, but eliminated as not feasible: . Area -wide lowering of groundwater table . Low-pressure sump -pump sewer systems . Enhanced Basement pumping . Installation of relief wells >; RAM Gfit<AT 13 JuVy2004 .v __ - . Study of Groundwater Related Flooding Problems RECOMMENDATIONS . General Recommendations . Area Specific Recommendations On -Site Homeowner Based Solutions Costs & Funding Options JuYy2QQ4 ,�.ta.f iSa1, 14 7 Study of Groundwater Related Flooding Problems SOUND ATTENUATED TRASH AND SEWER It is not only important to get the pumping accomplished, it is important to minimize disturbing the neighborhood. Sound Attenuated Pumps combine performance and quiet operation. Unit/Mod el Size Maximum Capaelty (GPH) Maximum Solids Maximum Head Sound Level STSS= it li.Mr r 14V 70� GTSC-= P gap" r 141r 74 dB. GTW-sa or samn r 114W 72 MI„ Juy 2004 17 Study of Groundwater Related Flooding Problems Pump Connection Examples '„v ya�i—p_*ty3h•{,,. .� � YS s s? Jury 2004 <;:5,- ..::..::..:::::..:.:... 18 9 SUMMARY OF RECOMMENDATIONS for HIGH SEVERITY PROBLEM AREA Area Area Name e=oende..d........ Estimated Estimated N - _-_-_ -- -_ _... s CapitalCoabs Annual09.M.. Install30 catch basin -leaching structures. Purchase 2 2 VINEYARD undeveloped lots toincreaseoff-street storage. Buldfacilitiesto (sheet 1of 13) pump excess floodwater to subsurface storage & recharge 5934550 $14400 facilities to be constructed at town parking lot. Install 18 catch basin -leaching structures. Purchase 3 7 ANASTASIA undeveloped lots & one house lot to increase off-street storage. (sheet 5 of 13) Build facilities to pump floodwater to a new storage & recharge 5998,600 $11,900 facility yo be constructed at Tabor Road, 13 MULFORD STREET Instail6 catch basin -leaching structures. Purchase 2 home sites $933,200 58,800 (sheet 7 of 13) that flood, increase off-street storage and raise Mulford Street, Purchase 4 home sites that flood and convert to increased off- street storage, and purchase 4 undeveloped lots to provide 15 CAP-f, VILLAGE increased off street storage (both storage areas require raising $1 9C>8,775 $15,600 (WEST) (sheet 9 of 13) road grades), Build facilities to pump excess floodwater to existing town drainage lot. (Emergency pump solution coordinates with Captain's Village East improvements). Install 10 catch basin4eaching structures. Increase off-street CAPT. VILLAGE storage at two existing town drainage lots. Build facilities to pump 14 (EAST) floodwater to new subsurface storage & recharge facility to be 51,514,350 $8,900 (see sheet 8 of 13) constructed at the Dennis -Yarmouth Regional School. (Emergency pump solution coordinates with Captain's Village West and Mulford Street improvements). FUNDING OPTIONS Local Funds . Roadway Management System . Drainage Capital Funds . Cape Cod Land Bank . Stormwater Utility (as yet, un-established source) State & Federal Funds . Conservation Grants . Community Development Block Grants (HUD) . S.399 and CWSRF grants and loans July2000. _;f' 20 10 Study of Groundwater Related Flooding Problems TOWN -WIDE COST & FUNDING SUMMARY Phase General Description Est. Cost' Alt, Funding Sources" All General Admin.IRecomm. $200,000 RMS, Operating Budgets Phases Phase I Vpgradient Drainage Sys. $610,000 RMS, Drainage, Grants Phase II Land Purchases 52,900,000 LB, CPA, Water, TMtg, Betterments, Grants Phase III Improvements after Land $690,000 RMS, Drainage, Grants Purchases Phase IV Remaining Infrastructure $3,100,000 Betterments, TMtg, Grants TOTAL $7,500,000 -Annual O&M costs (typically ranging from 1 % to 2%of the capital costs per year) would he additional. "- RMS: Roadway Management System; LB: Land Bank; CPA: Community Preservation Act; TMtg: Town Meeting These are total costs, for all priority areas, and all solutions....Not all may be neededl Plan is to Implement solutions by priority, step-wisel Then Track resultst >:> A0il oc-1, July 2004 V, N - 21 Example - Cost per homeowner (high priority areas only) CostlWcme l Torun Pays.... z N IOU Eli,# July 2004 'vo->' 22 Number of If 100% Homeowner for C13`s & for CB's, Land and Land 11 Making it Happen ON -SITE I HOMEOWNER METHODS Low cost ways that you can help to prevent flooding in your area. • Reduce stormwater run-off (and reduce sump pump discharges) to streets and storm sewers • Reduce Impervious Surfaces • Eliminate Basements that flood . Capture water as a resource for later reuse • Use Rain Barrels and Rain Gardens for roof runoff • Use Rain Gardens to receive and treat sump -pump discharges ?: R.13:#.l A01.P 23 July 2004 �' --_ _.. - 12 Study of Groundwater Related Flooding Problems RAIN GARDENS r i / 9 i f{ 7- i � F .. awrd.;� Y July 2004 13 Making It Happen Contact your Selectmen - ask for help For Land Bank Funds For Grant Fund Applications Political Process If the Selectmen choose to ask for additional funds to finance implementation of all or some recommendations: - then Town Meeting and/or a Ballot question would be needed. If the Selectmen choose to use the Betterment Fee process to fund all or or some recommendations: then a series of public meetings would be needed Nofam.-K. July 2004 27 Study of Groundwater Related Flooding Problems Open Discussion Questions & Answers July 2004 28 14 dam' c O - 4-0 uj rn LLJ r4 C a CL ui 0 m c r6 a uj m U L w LU V) A Ln m C C� v a m a CL Q O O m w V LL K w N R CL f * s J A lit t .. .s.,. R ?j it Ell tip 8 � ;J aO QJ tio 41 c LJJ n 0 N r- m 0 a r Q � LU u � O bA O m a LU c m U w LU �l E Z Q � _ J L tlp cd A III a� t v r6 cu Ln A N Cr'1 O Z Q 2 oc w c� r U O Oo O m Ia. Z Q 2 Lu L Iwl r`3 N O Q 2 a M r� r W Z U W M r ry IRr T r (D M ti T w M ri�j !,Oil T co T 1" n T M T )F T