ITEM DESCRIPTION:
Title
2nd Reading - Ordinance No. 2024-O-05 - Request to update Article IV “Resource Protection Standards” and V “Site Design Criteria” of the City of Edgewater’s Land Development Code.
Body
DEPARTMENT:
Environmental Services
SUMMARY:
On July 3, 2023, City Council authorized the engineering firm Jones Edmunds, Inc. to review and comment on the City of Edgewater’s Stormwater Codes and Standards. Brett Cunningham, P.E. with Jones Edmunds, Inc. presented the findings to City Council at their August 14, 2023 meeting. A copy of the Technical Memorandum containing their recommendations in attached.
Staff has proposed updated language to the various section of the Comprehensive Plan and Land Development Code to implement the recommendations. Mr. Cunningham reviewed and approved the proposed language.
The proposed updates to the Land Development Code are summarized below:
• Article IV “Resource Protection Standards”, Section 21-42 “Flood Plains”, paragraph 21-42.02.e.3.(b) relates to development activities proposed to be located in a riverine flood hazard area for which base flood elevations have not been designated. The adopted language restricts the acceptable degree of rise related to all anticipated encroachments in the riverine flood hazard area to no greater than 1-foot. The upgraded standard reduces this acceptable level of rise to four (4) inches.
• Section 21-42.04c.1.(c) and (d) relates to Flood Resistant Development standards pertaining the engineering site plans for new subdivisions and mobile home parks. This section has been upgraded to broaden the applicability of providing drainage paths within certain flood hazard areas. The new standard applies to all A-series flood hazard areas to avoid creating disconnected or isolated pockets with inadequate discharge paths.
• Article V “Site Design Criteria”, Section 21-53 “Stormwater Management Requirements”, paragraph 21-53.02 “Permit Authority” as adopted only recognizes the St. Johns River Water Management District (SJRWMD) as the sole outside agency with jurisdiction regarding stormwater management permits, however there are many other agencies which have various regulatory authority pertaining to matters related to stormwater management. The upgrades to this section seek to recognize the jurisdiction of such State and Federal agencies and authorizes the City to accept stormwater management system designs meeting the criteria of those regulatory agencies where such criteria are determined to be at least equal to, or more protective than City standards. Further, the code as adopted explicitly restricts the City’s ability to disapprove or refuse to issue a City stormwater permit where an Applicant has obtained a SJRWMD permit. The upgraded language re-instates the City’s right an independent review and decision.
• Section 21-53.03 “Exemptions to Permit Requirements” includes upgraded language whereby any activity, even those otherwise exempt, which is found to cause or contribute to a violation of any part of the Site Design Criteria standards will require issuance of a City stormwater permit to continue.
• Section 21-53.03.f. exempts very small amounts of impervious surface. The upgraded language specifies that such de minimis amounts of impervious surface are only exempt if they do not, in essence, cause a nuisance pertaining to runoff patterns.
• Section 21-53.04 “General Design Standards”, paragraph a. expands upon the accepted engineering methodologies for properly analyzing the behavior of stormwater runoff of a particular site or wide area basin. It is noted, the new language primarily applies to very sandy soils with a fairly deep water table. Edgewater has very few undeveloped lands which are expected to meet this definition. Nevertheless, the methodologies are generally accepted by the scientific and regulatory community and shouldn’t be excluded simply on a preference for one other methodology.
• Section 21-53.04.b. the proposed language reduces the number of hard-copy versions of engineering documents to be submitted and clarifies that such calculations should be signed and sealed by an appropriately licensed professional. The upgraded language also codifies recent practice waiving the need to involve a licensed professional engineer to produce stormwater calculations for small construction projects involving less than 9,000 square feet of total impervious surface. This standard was purposefully selected to match with the State-level threshold above which engineering design is required. The proposed language further clarifies the intent of the term “impervious surface.”
• Section 21-53.04.d. is upgraded to authorize the City to work toward meeting the goals of the State and Federal Environmental Protection Agencies regarding impaired waterbodies. This is accomplished by the USEPA and FDEP establishing, among other things, a Basin Management Action Plan (BMAP) or those agencies accepting a Reasonable Assurance Plan (RAP) produced by the regulated local governments. The main action item of a BMAP or RAP is typically to identify the target-level quantity of whichever parameters are determined to result in the type of impairment seen in the subject waterbody and then subdivide that target-level quantity among all stakeholders which contribute runoff into that water body in the form of Total Maximum Daily Limits (TMDL). Typically, these plans include a gradual reduction in the TMDL allocations over a period of years in order to reduce or remove the impairment designation. The upgraded language authorizes Staff to assess the proportionate share of such reductions onto any proposed development within areas contributing runoff to the impaired waterbody.
• Section 21-53.04.e. promotes the use of retention, meaning the percolation of stormwater runoff through the vegetated soil media into the surficial groundwater, where the drawdown recovery of such retention ponds can occur in less than 72 hours with an appropriate margin of safety. This cannot be accomplished everywhere as it relies on specific characteristics of the site’s soils, elevation, and other factors. As adopted, this paragraph requires one certain type of stormwater treatment system in those areas which cannot be served by retention alone. By changing “shall” to “may”, and in conjunction with the changes proposed in paragraph f., allows a variety of stormwater management systems to be used to best suit the site, while still favoring the use of retention.
• Section 21-53.04.f. the proposed language removes a too-narrow requirement regarding certain types of stormwater management systems which could be approved if permitted by SJRWMD. The upgraded language adopts the full range of stormwater system design and performance standards allowed by SJRWMD in their literature for a variety of treatment system components.
• Section 21-53.04.g. specifies a higher amount of water quality treatment on larger properties: one-half inch (1/2”) for properties smaller than 10,890 sqft and one-inch (1”) for all properties larger than that. The upgraded language clarifies how this amount is calculated and does not require the treatment volume to include any rainfall directly into a river, undisturbed wetland, or conservation buffers adjacent to those areas.
• Section 21-53.04.h. removes a provision which is now redundant to the upgraded subpart f and replaces it with an encouragement to include Low Impact Development (LID) techniques in developments, as required by the Comprehensive Plan.
• Section 21-53.04.i. and j. are upgraded to be consistent with current State law which forbids local governments from withholding or conditioning the issuance of a City-issued permit until another agency issues a permit.
• Section 21-53.04.k. is upgraded to better define the design storm events, which include the Mean Annual, 25-year, and 100-year storms. The requirements for full on-site retention are also better defined.
• Section 21-53.04.l. is upgraded to reflect the most current statistical data sources for precipitation amounts and clarifies the methodologies used to model how those amounts are distributed.
• Section 21-53.04.m. is upgraded to require a 10% reduction in discharge rate from any site which flows into a drainage system which serves areas impacted by the 100-year floodplain. The definition of this floodplain may be either as provided by FEMA or as adopted by the City based on wide-area hydrologic and hydraulic modeling.
RECOMMENDED ACTION
Staff recommends approval for Ordinance 2024-O-05.