Stormwater Pond “Parts” & h k !& When To Take Action!

This short guide will help you determine what steps to take to maintain yourstormwater pond, and when to seek professional assistance.

Delaware Department of Natural Resources and Environmental ControlDivision of Soil and Water Conservation, Sediment and Stormwater Program302-739-9921

May 2007

Let’s Get Started1. By regulation, the State of Delaware requires

property owners to maintain the stormwatermanagement facility (must function properly).

2. This includes commonly owned ponds, for example, astormwater management pond that exists in commonground of a community development.

3. First, obtain the most recent maintenance inspectionperformed by the Delegated Agency, to assist youin deciding what repairs are required, versus whatn c ng what r pa rs ar r qu r , rsus whatis optional.

4. The Delegated Agency is the agency in Delawarethat implements the Delaware Sediment andStormwater Regulations at the local level. Thisagency is also responsible for maintenanceagency is also responsible for maintenanceinspections. The Delegated Agency in which youseek assistance will depend on where you live.Please see the next page for a listing of theDelegated Agencies and their jurisdiction.

5 N h h i f i i d i hi hi5. Note that the information contained within thisguidance document may vary slightly from oneDelegated Agency to another. Before acting,always contact the Delegated Agency to verify thatthe proper action is being taken. Some Delegatedp p g gAgencies, such as New Castle County and the Townof Middletown, may even perform majormaintenance corrections on stormwater facilitieswithin their jurisdiction. To find out, please contactyour Delegated Agencyyour Delegated Agency.

LIST OF DELEGATED AGENCIES

Department of Natural Resources & Environmental ControlD f l d W CDivision of Soil and Water ConservationSediment and Stormwater Program89 Kings HighwayDover DE 19901Phone: (302) 739-9921http://www.dnrec.state.de.us/DNREC2000/Divisions/Soil/Stormwater/StormWater.htmResponsible for all aspects of administration of the state sediment and stormwater p p

management program under the Delaware Sediment and Stormwater Law and Regulations. Responsible for plan review and inspection of State and Federal Projects.

Department of Transportation800 Bay RoadP.O. Box 778Dover DE 19903D DE 99Phone: (302) 760-2251 http://www.deldot.net/Delegated Area: DelDOT Construction

New Castle CountyNew Castle County Dept. of Land UseLicensing DivisionLicensing Division87 Reads WayCorporate CommonsNew Castle DE 19720Phone: (302) 395-5400 http://www.co.new-castle.de.us/landuse/home/webpage1.aspDelegated Area: All unincorporated areas of New Castle County

New Castle Conservation District2430 Old County RoadNewark DE 19702Phone: (302) 832-3100, Ext. 3 Delegated Area: All Incorporated areas of New Castle County (except City of Newark, City

of Wilmington and Town of Middletown).

City of NewarkPublic Works Department220 Elkton RoadNewark DE 19711Phone: (302) 366-7040http://newark.de.us/docs/departments/public_works.htmlDelegated Area: City of Newark

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LIST OF DELEGATED AGENCIES Continued…

City of WilmingtonDept. of Public Works800 North French StreetWilmington DE 19801Phone: (302) 576-3056 http://www.ci.wilmington.de.us/departments/pubworks.htmD l d f lDelegated Area: City of Wilmington

Town of Middletown19 West Green StreetMiddletown DE 19709Phone: (302) 378-2711

http://www.middletownde.org/town_offices.htmDelegated Area: Town of Middletown

Kent CountyKent Conservation District800 Bay Road, Suite 2Dover, DE 19901Dover, DE 990Phone: 302-741-2600 (X 3)http://kentcd.org/Delegated Area: Kent County

Sussex CountySussex Conservation District23818 Shortly Road23818 Shortly RoadGeorgetown DE 19947Phone: (302) 856-7219 http://www.sussexconservation.org/sed_sw.htmDelegated Area: Sussex County

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Typical Stormwater Pond (Excavated)

Stormwater Pond Parts…Typical Stormwater Pond (Excavated)

Outlet Structure Safety Benches

Embankment on Stormwater Pond

Inlet

When a pond can’t beexcavated, an earthen damk b k t

Pond Embankment

Embankment on Stormwater Pond

known as an embankmentmust be constructed witheither clay or a liner to retainwater.

ACTION ITEMACTION ITEMDo not plant large trees on embankment. Remove saplings as necessary.

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Outlet Structure

The outlet structureallows water to flowout of the stormwaterpond at a regulatedwater level.

ACTION ITEMSRemove debris from outlet structure. M 10 f t th t tl t

l

Mow a 10-foot access path to outlet.Hire a professional if structure is cracked or broken.

Inlet

Water flows intopond through theinlets. Keep inlett t f fstructures free of

debris and trash.

ACTION ITEMSRemove debris from all inlet structures. Mow 10-foot access path to outlet.Hire a professional if structure is cracked or broken.

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Every pond must have an emergency spillway. Water can overflow at thislocation if it becomes overly full due to a significant rain event.

Emergency Spillway

Rip Rap Emergency Spillway

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Concrete Emergency Spillway

ACTION ITEMHire a professional if structure is cracked or broken.

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Trash RackA trash rack keepsA trash rack keepstrash and debris fromexiting the pond.

Trash Rack on Low Flow OrificeThe low flow orificeregulates the water levelin pond.

ACTION ITEMACTION ITEMRemove trash and debris from the trash rackand outlet to allow water to exit thestormwater pond.

Concrete Weir

A concrete weir is notfound on all stormwaterponds. It functions toretain water andregulate water level.

ACTION ITEMHire a professional if structure is cracked or broken.

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Safety Bench There are typically two safety benches in a stormwaterpond, one 1-foot above the permanent pool of water andone 1- foot below. This feature is called a safety benchbecause it is intended to safeguard someone if they fallin or near the pond.

Forebay

A forebay concentratessediment into one areato decrease dredgingcosts later.

ACTION ITEMHire a professional to remove sediment (dredge the forebay) on an as needed basis.

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Pond Buffers(“No Mow Zone”)

Buffers are optional, notp ,required. There are threemajor benefits of buffers.First, they providenecessary habitat forwildlife. Second, they filterthe water as it enters thepond, removing nutrientssuch as Nitrogen andPhosphorus. Third, theydeter geese from enteringthe pond which will

ACTION ITEM

the pond, which willreduce potentially harmfulbacteria from entering thewater.

ACTION ITEMBuffers are optional. The entire homeowner’sassociation should agree with the buffer widthdecision. Also work with your lawn care company toachieve the desired goals.

Aeration

Pond aeration provides oxygen in the water column, vital for thesurvival of aquatic organisms like fish. There are many differenttypes of aeration systems. Some types even have the addedbenefit of reducing mosquitoesbenefit of reducing mosquitoes.

OTHER ACTION ITEMAeration systems are optional. Hire a professional toinstall and maintain your aeration system, if yourhomeowner’s association or maintenancecorporation agrees on this optioncorporation agrees on this option.

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CASE STUDIESWh d I hi f i l?When do I hire a professional?

What can I do myself?

Here are some examples.

ACTION ITEMClean trash. To save on cost, do it yourself.

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ACTION ITEMSContact your Delegated Agency for the most recent maintenanceinspection. Hire a professional to remove vegetation (in this instancewill be mechanical and chemical). We do not recommend doing thisyourself. Hire a professional who has both a commercial applicator’slicense and aquatic pesticide applicator’s license through the Delawarelicense and aquatic pesticide applicator s license through the DelawareDepartment of Agriculture. Also, removing the fencing isrecommended, but not required.

OTHER ACTION ITEMSHire a professional to remove excess sediment fromthe pond, if determined by a maintenanceinspection. This can be costly ($$$), depending onsediment removal. The professional should obtainengineering plans prior to dredging to minimize the

Fencing is not required. Some insurance companies will require fencing to beinstalled in order for the maintenance corporation or homeowner’s association

A Note of Fencing

possibility of damaging the pond liner if one exist.

installed in order for the maintenance corporation or homeowner s associationto be covered by liability insurance. In Delaware, fencing is not recommendedbecause it makes maintenance of stormwater ponds difficult and can deteraccess should an emergency arise.

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ACTION ITEMSRemove vegetation from outlet. To save on cost, do ityourself. Additionally, you can choose to hire a year-roundprofessional for permanent algae control (optional) Weprofessional for permanent algae control (optional). Werecommend that you not do this yourself. Hire a professionalwho has both a commercial applicator’s license and aquaticpesticide applicator’s license through the DelawareDepartment of Agriculture.

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ACTION ITEMMajor structural repairs are necessary. This willbe costly, but must be done. Leaving thestructure in this state can be dangerous. Youmust first obtain guidance from the DelegatedAgency, followed by hiring a professional tocomplete the repair (costly$$$).

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ACTION ITEMSDecrease the use of lawn fertilizers throughout thecommunity Work with your lawn care company to be surecommunity. Work with your lawn care company to be surethat grass clippings are not dumped into the pond. This willreduce nutrients into the system. Algae removal is optional(not required). We recommend not to do this yourself. Hire aprofessional who has both a commercial applicator’s licenseand aquatic pesticide applicator’s license through theDelaware Department of Agriculture.p g

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ACTION ITEMSStabilize banks of pond. If erosion is severe enough, hire aprofessional. If erosion is minor, do it yourself to save oncost. In the spring or fall, till ground and clear soil of debrisand rocks. Seed with perennial species and mulch (strawworks well). Water frequently until vegetation is established.

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ACTION ITEMSACTION ITEMSDNREC Mosquito Control will sample the pond to see if thesource of mosquitoes is coming from your pond. If so, theywill treat for mosquitoes, free of charge.

New Castle County 302-836-2555Kent & Sussex Counties 302-422-1512

Other options? Call a professional to determine if the p pintroduction of Gambusia (mosquito fish) would be appropriate for the stormwater pond.

OTHER ACTION ITEMSContact your Delegated Agency for a maintenanceinspection. Hire a professional to remove vegetation (in thisinstance will be mechanical and chemical) We recommendinstance will be mechanical and chemical). We recommendthat you not do this yourself. Hire a professional who hasboth a commercial applicator’s license and aquaticpesticide applicator’s license through the DelawareDepartment of Agriculture.

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ACTION ITEMSDecrease the use of lawn fertilizers throughout thecommunity. In this instance, vegetation removal is optional;however, we recommend that you not do this yourself. Hire a, y yprofessional who has both a commercial applicator’s licenseand aquatic pesticide applicator’s license through theDelaware Department of Agriculture. The introduction of grasscarp is not permitted in stormwater ponds in the State ofDelaware.

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ACTION ITEMSNo action is required for goose control; however, leaving abuffer will deter the geese from staying at your pond. Otheroptions also exist that will deter geese; however, they can

t b d lf Hi f i l h hnot be done yourself. Hire a professional who hasexperience with goose control.

OTHER ACTION ITEMSDecrease the use of lawn fertilizers throughout the community.In this instance, vegetation removal is optional; however, we donot recommend that you do this yourself. Hire a professionaly y pwho has both a commercial applicator’s license and aquaticpesticide applicator’s license through the Delaware Departmentof Agriculture. The introduction of grass carp is not permitted instormwater ponds in the State of Delaware.

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